Inverted Carrier Lift Device System and Method
1. A method for manipulating the position of a workpiece in a workstation, the method comprising:
- transferring a trolley engaged with a conveyor along a path of travel to a predetermined position at a workstation, the trolley connected to a carrier having a workpiece support beam operable to support a workpiece;
lowering the carrier relative to the trolley by a lifting mechanism from a raised position to a lowered position along a carrier axis of travel in the workstation;
conducting a process on the workpiece;
raising the carrier from the lowered position to the raised position in the workstation by the lifting mechanism; and
transferring the trolley from the predetermined position at the workstation by the conveyor along the path of travel.
An inverted carrier lift and method is disclosed. The inverted carrier lift includes a trolley movable along an overhead conveyor and a carrier for supporting a workpiece to undergo an assembly or manufacturing process. The carrier is movable relative to the trolley from a raised position to a lowered position by a motor engaged with a lifting mechanism on the trolley. On rotation of the motor, the carrier and supported workpiece is lowered or raised to position the workpiece in the workstation for processing. The workpiece may be disengaged by the carrier for support of the workpiece by one of many different fixtures depending on the processing. Following processing, the workpiece is re-engaged by the carrier, moved to a raised position and the trolley is transferred to a subsequent workstation.
- 1. A method for manipulating the position of a workpiece in a workstation, the method comprising:
transferring a trolley engaged with a conveyor along a path of travel to a predetermined position at a workstation, the trolley connected to a carrier having a workpiece support beam operable to support a workpiece; lowering the carrier relative to the trolley by a lifting mechanism from a raised position to a lowered position along a carrier axis of travel in the workstation; conducting a process on the workpiece; raising the carrier from the lowered position to the raised position in the workstation by the lifting mechanism; and transferring the trolley from the predetermined position at the workstation by the conveyor along the path of travel.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
The present application is a divisional application of U.S. patent application Ser. No. 15/588,326 filed May 5, 2017 which claims priority benefit to U.S. Provisional Application No. 62/332,598, filed May 6, 2016, and U.S. Provisional Application 62/433,405, filed Dec. 13, 2016, the entire contents of each application are incorporated herein by reference.
The present invention pertains generally to assembly systems, particularly of the type including conveyors defining a path of travel between workstations for conveying of a workpiece to one or more workstations positioned along the path of travel.
In automotive production lines, individual workpieces, such as automotive body panels, frame components, etc., may be transported between workstations where selected operations, such as welding or other joining operations, are performed by workers, robots, or other processing equipment. Transporting individual workpieces to, and accurately placing the workpieces at, a desired workstation on a production line poses numerous difficulties. Tooling and other processing equipment at a workstation present obstacles that must be avoided by the incoming and departing workpieces. After reaching a given workstation, the workpieces must be accurately positioned within the workstation to allow necessary processing operations to be performed. Efficiency and accuracy requirements of modern production lines require that workpiece delivery to a workstation be as rapid and precise as possible.
In many common production lines and other assembly applications, workpieces are transported along an overhead rail, for instance a monorail. Powered roller rail systems move support trolleys or carriages between various workstations. Electrical conductors can be provided along the rail to provide power to the trolley motors. The trolleys carry workpieces along the path defined by the rail, delivering the workpieces to the workstations. To perform a processing operation on a workpiece transported along an overhead rail, often a mechanism must be provided to raise and lower the workpiece with respect to the workstation to properly position the workpiece in the workstation. Prior powered roller rail and trolley systems and devices used to raise and lower workpieces in a workstation include those described in U.S. Pat. No. 6,799,673; U.S. Pat. No. 9,513,625; and U.S. Patent Application Publication No. 2015/0128719 assigned to the assignee of the present invention and all incorporated herein by reference.
Many prior known mechanisms for raising and lowering a workpiece into the workstation have moved the entire workpiece-laden trolley along with an entire section of the overhead rail. This type of mechanism is complicated in design and prone to wear. For example, joints must be provided between the fixed and moveable rail sections to disengage and re-engage the rail and/or trolley to the main conveyor mechanism. It can be difficult to ensure that the section of rail lowered with the trolley is properly realigned with the fixed rail sections. This negatively impacts the operational capacity of the production or assembly lines, for instance by causing wasteful “down-time” for repairs. In addition to the foregoing disadvantages, many prior known mechanisms cycle at relatively slow speeds, since the weight of the carrier, trolley, and rail must all be borne by the movement mechanism. Consequently, a need exists for a simplified lifting mechanism that meets the efficiency requirements of modern production and assembly lines, and which is simple in operation.
The inventive inverted carrier lift device system and method is useful to transport a workpiece along an assembly line and to selectively lower and raise the workpiece in a predetermined area for processing or temporary storage of the workpiece. The carrier lift may selectively and automatically release the workpiece into a fixture or other device for processing and thereafter automatically re-engage the workpiece for continued movement along the assembly line.
In one example, the carrier includes an onboard lifting mechanism having a ratcheting device and a tether for raising and lowering a support beam engaged with the workpiece through workpiece engaging devices. The lifting mechanism is selectively engageable with a motor stationarily positioned at a workstation which rotates the ratchet device to raise and lower the workpiece. In a lowered position, the workpiece engaging devices are automatically actuated to release the workpiece from the support beam into a desired holding fixture or other device for further processing or storage. Following further processing or storage of the workpiece in the workstation, the carrier is positioned, lowered and automatically re-engaged with the workpiece. The carrier is then raised by the lifting mechanism and selectively moved along the assembly line to another predetermined position.
In one example, the ratchet device includes a drum which threadingly engages a single tether connected at both ends to the workpiece support beam, on rotation of the ratchet device by the motor, the tether is spooled onto, or unspooled from, the drum to raise or lower the workpiece respectively.
In another example, the carrier is connected to a trolley engaged with and elevated or overhead conveyor for movement of the carrier along an assembly line through a plurality of workstations.
In another example, the carrier is used with a trunnion fixture positioned in a workstation along the assembly line. At a lowered position, the carrier positions and releases the workpiece to the trunnion fixture which rotatably manipulates the workpiece to one or more predetermined positions for processing of the workpiece.
The inventive method for raising and lowering a workpiece in a workstation is useful for selectively vertically positioning a workpiece in a workstation for processing or temporary storage of the workpiece in the workstation or other location. In one example, a carrier is connected to a trolley engaged with an elevated or overhead carrier movable along an assembly line. The carrier selectively raises or lowers the supported workpiece relative to the trolley to position the workpiece on a fixture or other device positioned in the workstation.
In one example of the method, the carrier automatically releases the workpiece into the fixture or other device and then re-engages the workpiece following processing or storage for further movement along the assembly line.
In another example an alternate lift mechanism including an extension device using scissor links is used to raise and lower the workpiece.
In another example, the actuating motor for selectively raising and lowering the workpiece is onboard the lift carrier instead of stationarily positioned at the workstation independent of the carrier.
These and other aspects of the present disclosure are disclosed in the following detailed description of the embodiments, the appended claims and the accompanying figures.
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
As best seen in
The powered rollers 26 may be controlled by a programmable control system used to monitor, sequence and control the movement of the individual inverted carrier lift trolleys discussed below along an assembly line. One example of a suitable control system is described in U.S. Patent Application Publication No. US 2010/0241260 assigned to the assignee of the present invention and incorporated by reference herein.
The inverted carrier lift 10 may be selectively and precisely positioned at one or more locations in a workstation through a closed loop control system including an optical reader positioned at the station and coded strips or other devices on the carrier 27. The coded strips may be specific to the particular carrier lift 27 or the workpiece transferred by the carrier 27 such that on a carrier 27 entering a workstation, the optical reader scans the coded strip identifying information on the strip, which may be particular to the specific carrier 27, and the carrier 27 can be stopped at a predetermined or optimal position in the workstation for the work to be performed on the workpiece. One suitable transport monitoring, control and positioning system is disclosed in U.S. Pat. No. 7,108,189 owned by the assignee of the present invention and is incorporated herein by reference. An example of the coded strip is shown atop rail 23 in
As best seen in
The exemplary inverted carrier 27 includes a workpiece support beam 36 suspended from the trolley 28 by two telescopic posts 38. The workpiece support beam 36 is selectively movable between a raised position, for example, as shown in
In the example, each telescopic post 38 includes a lower post member 44 slidably received within an upper post member 46. In the illustrated exemplary configuration, the upper post member 46 is shown attached to the trolley 28 and the lower post member 44 attached to the workpiece support beam 36, but in practice, the orientation of the telescoping post 38 may be inverted, such that the lower post member 44 is attached to the trolley 28 and the upper post member 46 is attached to the carrier 36. As illustrated, when operating the carrier 27, the lower post member 44 moves progressively further into the upper post member 46 when moving the workpiece support beam 36 toward the raised position, and extends progressively further out from the upper post member 46 when moving the workpiece support beam 36 toward the lowered position. The telescopic post 38 may include an alternate configuration to accommodate the design and performance requirements of a particular application. More than two telescopic posts 36 may be employed with the carrier 27.
Referring to the example carrier 27 shown in
With reference to the example shown in
In one example of the illustrated tether 54, tether 54 includes a single, continuous member that is threaded through the ratchet mechanism 56 further discussed below, and attached at both a first end 58 and a second end 60 to the carrier 36 at a first attachment point 59 and a second attachment point 61, respectively. A buckle 62 may be used to attach the ends 58 and 60 of the tether 54 to the carrier 36.
In the example shown, tether 54 passes through a pair of pulleys 64 attached to the support member 30 spaced on either side of the ratchet mechanism 56 as generally shown. As best seen in
The pair of pulleys 64 may be spaced apart along the guide rail 24 by a distance that approximates the spacing between the attachment points 59 and 61 of the tether 54 to workpiece support beam 36. To maximize lifting efficiency of the lifting mechanism 52, the pulleys 64 may be spaced such that portions of the tether 54 located between the pulleys 64 and the tether connection points 59 and 61 are arranged substantially parallel to one another. A different pulley 64 spacing may be employed, but may result in reduced lifting efficiency.
In the example shown, the drum 72 includes a first drum end plate 80 and a second drum end plate 82. A plurality of elongate rods 84 extend between the first 80 and second 82 drum end plate, each rod with a first end 86 attached to the first drum end plate 80 and an opposite second end 88 attached to the second drum end plate 82. In one example, the rods 84 may be arranged generally perpendicular to the first 80 and second 82 drum end plates. The rods 84 may also be arranged in a circle so as to form linear segments generally defining an outer perimeter of a cylindrical-shaped structure extending between the first 80 and second 82 drum end plates. In the example best seen in
As best seen in
Although lifting mechanism 52 is described and illustrated as including a single continuous tether 54 threaded through the ratchet mechanism 56, alternately, two or more tethers may be used in place of the single tether 54. For example (not shown), one tether may have a first end attached to the carrier 36 at the first attachment point 59 and a second end attached to one of the rods 84 of the ratchet mechanism 56 (or other reel or take-up device). Similarly, a second tether (not shown) may have a first end attached to the carrier 36 at the second attachment point 61 and a second end attached to one of the rods 84 of the ratchet mechanism 56 (or other reel or take-up device). The lifting mechanism 52 will operate in a similar manner to reel in or out a length of the tether(s) whether employing a single tether or multiple tethers.
In one example of engagement of the above described motor coupler (not shown), the motor 57, the motor shaft 96 or other structure (not shown) is actively extended in a direction toward the ratchet coupler 104 to position the motor coupler lobes into the coordinating openings 100 in the ratchet coupler 104 such that rotation of the motor shaft 96 equally rotates the ratchet coupler 104 and drum 72. On completion of the processing at the workstation, the motor 57, coupler, shaft 96 or other device is retracted in a direction away from the ratchet coupler 104 to disengage the motor coupler lobes from the ratchet coupler openings 100 thereby clearing the motor coupler from the ratchet coupler 104 so the trolley can freely move from the workstation along the path of travel 21.
As best seen in
In one example of engagement of motor coupler 108 and alternate ratchet coupler 104A, on transfer of a carrier 27 into a workstation, the stationary motor 57 is horizontally aligned, and motor coupler 108 and ratchet coupler 104A automatically positioned, such that the motor coupler 108 planar plates 114 slidingly enter the ratchet coupler 104A through the respective spaces 118. On stopping of the carrier 27 at the predetermined position in the workstation, the planar plates 114 are positioned in abutting engagement, or are directly adjacent to, walls 116 and the motor shaft 96 rotational axis is aligned with the ratchet mechanism shaft 74 rotational axis. On rotation of the motor shaft 96, the planar plates 114 abuttingly engage the walls 116 causing equal rotation of the ratchet mechanism shaft 74 and the drum 72. On completion of the processing at the workstation, the motor coupler 108 is automatically returned to its original position, for example, where the planar plates 114 are aligned or parallel with the carrier 27 path of travel 21, such that on exiting of the carrier 27 from the workstation, the planar plates 114 freely pass through the openings 118 on the other side of the ratchet coupler 104A to clear the ratchet mechanism 104A from the motor coupler 108. Other devices, orientations and methods for aligning and engaging and/or disengaging the described motor couplers from the ratchet couplers 104, 104A may be used. It is further understood that different lifting mechanisms 52, ratchet devices 56 and drive sources such as motor 57 may be used to suit the particular application and performance specifications of the assembly line and system.
In one example of operation of the described motor couplers and ratchet couplers 104, 104A, one or more sensors (not shown) are used to monitor and control the rotational positions of one or both of the described motor couplers and the ratchet couplers so that the respective couplers are properly positioned in predetermined alignment as a carrier 27 enters the workstation in order to effect the respective engagement/disengagement scheme described above. For example, encoders may be used in a closed-loop system to monitor the rotational position of the motor shaft 96 and/or the ratchet shaft 74. In an example where an encoder is used for the motor shaft 96, the encoder can be in electronic communication, for example wired or through known wireless protocols, with a control system to send signals to the control system as to the present position of the respective shafts and/or couplers. The control system can compare the received current position of the motor shaft 96 (or motor coupler) and send signals to, for example, the motor 57 to ensure the motor coupler is in a position whereby the motor coupler is to properly engage or disengage the respective ratchet coupler 104, 104A at the proper point in time of the overall operating system. In one example, the described encoder is placed in communication with the control system previously described and detailed in U.S. Patent Application Publication No. US 2010/0241260. Other sensors, monitors, controllers and control systems may be used.
Referring to the exemplary ratchet mechanism 56 in
With reference to
In examples of an automated latch arm 134, for example by an electric motor or magnetically powered actuator, the motor/actuator may be connected to a control system having a controller (not shown). The control system would be operable to monitor and/or control actuation or movement of latch arm 134 between a latched and unlatched position through energizing the motor/actuator. One or more sensors (not shown), for example mechanical or electric switches or contacts, or optical/vision systems, may be used to monitor the position of the latch arm 134. The sensor(s) can also be in electronic communication with the control system to actively monitor the position of the latch arm 134, for example, a real time, closed-loop automated monitoring and control of the latching mechanism. The control system may include preprogrammed instructions whereby, for example, the motor 57 cannot be energized when the latch arm 134 is determined or sensed to be in a latched or locked position. Equally, conveying system 20, the lifting mechanism 52 and/or the ratchet mechanism 56 can also include sensors and be in electronic communication with the above-described local or central control system, as well as the respective individual mechanisms and systems, for a semi-automated, or fully automated, closed-loop operation for system 10.
In one example of inverted carrier lift system 10 shown in
In the example trunnion 152, two circular, generally disc-shaped end plates are used for engaging workpieces 146, including a first end plate 160 and a second end plate 162. The frame 150 includes one end 164 connected to the first end plate 160 and a second end 166 connected to the second end plate 162. The frame 150 and/or the end plates 160 and 162 may support clamps, tooling, fixtures, engagement pins, sensors and other devices for receiving, positioning and/or temporarily securing the workpiece 146 to the trunnion 152, for example to the frame 150, during processing of the workpiece 146. The workpiece 146 may be supported by the trunnion fixture 148 between the end plates 160 and 162. For example, the workpiece 146 may be transferred to the trunnion fixture 148, as shown, for example, in
One or more workpiece engaging devices (not shown) may be connected to and positioned relative to the frame 150 and/or the end plates 160 and 162. The workpiece engaging device may include a tooling, nesting or holding fixtures, locating pins, clamps, and other devices for guiding, positioning, engaging and/or securing the workpiece 146 to the trunnion fixture 148. Both the first end plate 160 and the second end plate 162 may be fitted with similar workpiece engaging devices, or with different configurations or operative devices. Electric or pneumatic power and/or controls for the workpiece engaging devices, or for other structures of the trunnion fixture 148, may be directed through an aperture 168 in the end plates 160 and 162 or by other devices or structures. Control of the exemplary workpiece engaging devices may be actively monitored and controlled by the control systems, devices, hardware and/or software in a manner previously described, for example described in U.S. Patent Application Publication No. US 2010/0241260. Other devices and methods of monitoring and controlling the position and actuation of workpiece engagement devices, either locally by the workstation, or centrally in the plant facility, may be used.
In one example of inverted carrier system 10, one or more workpiece engaging devices 147 are connected to the workpiece support beam 36 and/or auxiliary arms 50 (as shown) to removably engage and secure the workpiece 146 to the carrier 27, for example, workpiece support beam 36. In one example, on transfer of the workpiece 146 to the trunnion fixture 148 for workstation processing, the one or more workpiece engaging devices 147 are disengaged or otherwise, for example by an actuator (not shown), to release the workpiece 146 from the workpiece support beam 36 and/or the auxiliary arms 150, or otherwise the carrier 27.
In one example, none of the carrier 27, lift mechanism 52, or trolley 28 includes an onboard power generation devices or control systems that require a power connection to operate. For example, as illustrated and described above, lifting mechanism 52 does not require an onboard electrical motor to rotate drum 72 which would require a power connection or hook-up when the carrier 27 is positioned in the workstation. Rather, ratchet mechanism 56 is configured to be engaged by an electrical motor 57 which is stationarily mounted in the workstation. This is advantageous to reduce complexity of the system 10 and carrier 27. A further advantage is shorter cycle times through a reduced number of, or no required, connections of power to the trolley 28 and/or carrier lift 27 when the trolley 28 enters and exits a workstation.
In one alternate example (not shown), remote power or signals may be used in order actuate actuator(s) (not shown) for the above-described workpiece engaging devices 147 mounted on the workpiece support beam 36 in order disengage/engage the workpiece 146 for transfers between the carrier 27 and the trunnion fixture 148. For example, clamps (not shown) positioned on workpiece support beam 36 used to engage workpiece 146 may require electrical or pneumatic power to actuate the clamps between an open (typically disengaged position) and a closed (typically engaged) position. In one example, on the carrier 27 positioning of the workpiece 146 in the desired position, for example a fully lowered position thereby placing workpiece 146 in the proper position on trunnion fixture 148, cooperating and mating power connection modules or connectors are used on both of carrier 27 and the trunnion fixture 148 or the workstation. For example, as described above, the trunnion fixture 148 includes a power source (for example, electrical wiring harness or pneumatic tubing and valves with an end connector/module/plug/coupling) that may extend through aperture 168. Trunnion fixture 148 may further include a connector module, plug, socket or connector block vertically positioned in the lowering travel path of the carrier 27, for example the path of the horizontal member 48 and/or auxiliary arms 50. The carrier 27, for example workpiece support beam 36, can also include a coordinating and mating power connector/block/socket/plug/coupling that is aligned with the connector/block on the trunnion fixture 148.
On lowering of the carrier lift 27 to a position where the workpiece 146 is properly positioned on the trunnion fixture 148 for processing, the coordinating power modules/blocks on the carrier 27 and trunnion fixture 148 engage thereby completing a power circuit to provide power to the carrier 127 workpiece engaging devices to disengage the workpiece 146 from the carrier 27 such that the trunnion fixture 148 fully supports the workpiece 146 for further processing. On completion of the workstation processing on workpiece 146, the carrier 27 may be re-lowered into position such that the coordinating/mating power modules/blocks re-engage thereby providing power (for example electrical, data, pneumatic) to the workpiece engaging devices 147 on the carrier 127 to re-engage the workpiece 146 and remove the workpiece 146 from trunnion fixture 148 so that the carrier 127 may be transferred to a subsequent workstation for further processing. This example is advantageous as described above due to reduced equipment and complexity of mobile carrier 27.
In one example, the workpiece engaging devices connected to the trunnion fixture 148 may be powered and operated in a similar manner through the supply of power previously described. Monitoring, actuation and control of the workpiece engaging devices may be made through communication of such devices, or sensors in communication with the devices, by a local or central control system previously described and detailed in U.S. Patent Application Publication No. US 2010/0241260. Other devices and processes to engage/disengage the workpiece 146 from the carrier 27 and/or provide power to the carrier 27 and/or trunnion fixture 148 may be used.
In the example trunnion fixture 148, the end plates 160 and 162 are rotatably supported and frictionally engaged on the rollers 156 to promote selected rotational movement of the frame 150 and the end plates 160 and 162 about a longitudinal axis of the trunnion mounted fixture 148. In one example, an outer circumferential edge 170 of each roller 156 engages an outer circumferential edge 172 of the respective end plates 160 and 162. Each roller 156 may be rotatably connected to a bracket 174 fixedly attached to the base 158. Rotation of the rollers 156 causes a corresponding rotation of the respective end plates 160 and 162 about the longitudinal axis of the trunnion mounted fixture 148. The rollers 156 are suitably configured for supporting the weight of the end plates 160 and 162, the frame 150 and the workpiece 146 connected to the trunnion mounted fixture 148.
The respective outer circumferences 170 and 172 of the rollers 156 and end plates 160 and 162, respectively, may include mating contours to help minimize axial movement of the trunnion 152 relative to the rollers 156. For example, the outer circumference 170 of the rollers 156 may include a recessed groove 176 that rollingly engages a corresponding convex shaped outer circumference 178 of the end plates 160 and 162. Other contours may also be employed. The outer circumferences of the rollers 156 and the end plates 160 and 162 may employ or include materials configured to enhance traction between the rollers 156 and the end plates 160 and 162. In one example, the rollers 156 may be made of urethane to promote frictional contact with the end plates 160 and 162. Other materials and methods of engagement may be used. Other constructions and methods for preventing or minimizing relative axial movement between the end plates 160 and 162 and rollers 156 may be used by those skilled in the art.
With continued reference to
In operation, the drive 154 may rotate the trunnion fixture 152 in either rotational direction, as indicated by arrow 192 in
With reference to
In one example of rotary drive 154 not shown, a separate rotary drive 154 may be employed to separately drive the rollers 156 associated with each end plate 160 and 162. For example, with reference to
In an alternate example of rotary drive 154 shown in
In one example of described rotary drives 154, for example as illustrated in
It is further understood that the described workstation and process may not be an assembly or manufacturing workstation or area, but an alternate predetermined area along the assembly line path of travel 21 which serves as a temporary storage area or holding area for workpiece 146 (each considered a workstation for simplicity in this disclosure). For example, the workstation may be a production line buffer wherein workpieces that are in process are temporarily stored or racked until needed for the next stage of the assembly or manufacturing process.
Although shown as a trunnion fixture 148, different fixtures, tooling, racks and other movable and fixed devices suitable for supporting and securing workpiece 146 may be used (each referred to as a “fixture” for simplicity herein). For example, the fixture may be an indexing storage rack for temporarily holding a plurality of workpieces, for example in an in-process buffer area or an end-of-process storage area where completed parts await packaging and shipment. Other fixtures suitable for the particular workstation or process operation known by those skilled in the art may be used.
With reference to
With reference to
With reference to
The carrier 27 supports at least one workpiece 146 during movement of the carrier 27 along the guide rail 24 with respect to the workstation. The carrier 27 may be alternately moved between the raised position, as illustrated, for example, in
As previously described, in one example the carrier 27 is slidably associated with the trolley 28 so as to be moveable vertically in relation to the trolley 28 to lower the workpiece 146 into the workstation, and more particularly, the trunnion mounted fixture 148, without the necessity of lowering the entire overhead conveyor system 20, as with some prior known mechanisms. In one example, the workpiece 146 is released or disengaged from horizontal member 48 and arms 50 through release of clamps or other workpiece engaging devices 147 connected to horizontal member 48 and auxiliary arms 50 in engagement with workpiece 146. The clamps or other retaining devices may be electronically connected to and controlled by the local or centralized control system including sensors previously described above.
The workpiece 146 may be retained within the trunnion 152 by one or more workpiece retaining devices previously described. Once secured to the trunnion mounted fixture 148, the workpiece 146 is ready for processing, which may include, for example, rotating the workpiece on one or more positions, for one or more welding operations or a metal forming operation designated for that workstation. For example, one or more robots (not shown) may perform a welding operation on the workpiece 146 supported by the trunnion mounted fixture 148. In one example, the trunnion 152 may reposition the workpiece 146 to another position following a process. For example, following one welding operation at the workstation, the workpiece may be rotated to another position so that a second welding operation can occur allowing better access by the second welding robot.
When processing of the workpiece 146 is complete, the trunnion 152 may be rotated by the rotary drive 154 to a predetermined rotary position in preparation for removal from the trunnion mounted fixture 148 by the carrier 27. The controller 210 or the local or centralized control system previously described may then control the carrier 27 to engage the workpiece 146 to the carrier 36 and remove the workpiece 146 from the trunnion mounted fixture 148. On completion of the predetermined operations at the workstation, the motor 57 (
The exemplary carrier lift 310 is preferably includes trolley 28 engaged with an elevated or overhead conveyor 20 for movement of the trolley 28 and carrier along an assembly line path of travel 21 as previously described for alternate carrier 10.
Still referring to
In a preferred example, support beam 350 and arms 50, or other attachment and workpiece engaging devices, are modular in nature and can be quickly connected and disconnected to support beam 350 to quickly change the support beam 350 configuration to, for example, accommodate different components or vehicle styles to support dynamic random build sequences (vehicle models A, C, D, B, E), or batch build assembly sequences (vehicle models AAA, BBB, CCC, DDDD). Although shown as straight bars, support beam 350 and extensions 50 can take other forms, shapes and configurations to suit the particular application as known by those skilled in the art. Respective rails 30, beams 350 and arms 50 are preferably made from aluminum or steel but can be made from other materials known by those skilled in the art. It is further understood that support beam 350 can include workpiece engagement devices 147 as previously described (not shown in
Referring back to
In the example carrier lift 310 carrier 27A shown in
In the example carrier 27B and lift mechanism 352A shown in
The example carriers lifts 310 and carriers 27A, B and C shown in
Referring to the example carrier lift 310 and carrier 27A shown in
Referring to the example carrier lift 310 and carrier 27B shown in
Referring back to
In the example lift carrier 310 and carrier 27A-D shown in
For example carrier lifts 10, 310, a centralized controller (not shown) connected to, or onboard, carrier 310 may be in communication with other controllers or actuators onboard carrier 310 to execute signals which energize or actuate motor 357 and workpiece engaging devices 147. The carrier 310 central controller may be in communication, for example hard wire or wireless protocols, with a local workstation or assembly line controller or an assembly plant programmable controller to send and receive signals, data and/or instructions to actuate the motor 357 and workpiece engaging devices 147 in a predetermined sequence as generally described above or described herein. Equally, sensors (not shown) may be included for motor 357, workpiece engaging devices 147 and other equipment connected to carrier lift 310 to actively monitor, in a closed loop feedback system, the precise position and/or operations status of the respective equipment and send signals to the local or centralized assembly plant controllers and control system as previously described for carrier lift 10. The previously mentioned controllers and control systems may each include a central processing unit (CPU), memory storage devices for storing preprogrammed instructions and received signals and/or data, transmitters, receivers, input and output devices, and buses to place the respective components in communication with each other. Other devices for the described controllers and control system known by those skilled in the art may be used.
As best seen in
In the example, workstation 314B is an automated work station which may include, for example, a plurality of programmable multi-axis robots (not shown) to further conduct assembly operations on the progressively assembled workpiece 146. In the example workstation 314B, carrier lift 10, 310 and carrier 27A, B or C (C shown) may lower support beam 36, 350 and engaged workpiece 146 to a lowered position 416 to the workstation lower level 506, or to another elevation along travel axis 370, into what is schematically shown as a tooling area 420.
Tooling area 420 may be an area of the workstation which contains holding or welding fixtures, for example trunnion fixture 148 or other fixtures, tooling or supports described herein, which secure workpieces 146 in a predetermined position so that, for example, spot welding by the industrial robots can take place. In one example, lift mechanism 52, 352 selectively, for example through control signals sent by a local or central control system as described above, lowers the workpiece 146 onto the fixtures or other tooling in tooling area 420 and then disengages the workpieces 146 in a manner previously described by workpiece engaging devices 147, and then is raised to so as to be clear of the travel paths of the robots so the predetermined assembly or manufacturing work can take place.
On completion of the predetermined work in workstation 314B, in a preferred example, the carrier 27A, B or C positioned above the workpiece 146, rises and returns to workstation 314A to engage a new or next workpiece positioned in workstation 314A, rises and delivers the next workpiece in workstation 314B. The completed workpiece in workstation 314B is retrieved by a second carrier lift 10, 310 positioned in a subsequent workstation positioned downstream along path of travel 21 to retrieve the workpiece from workstation 314B and deliver it to the next downstream workstation (not shown) along path of travel 21. This process continues with the carrier lift 10/310 moving only between workstations 314A and 314B as the workpiece progressively moves down path of travel 21.
Alternately, carrier 10, 310 positioned in workstation 314B may be lowered, re-engage workpiece 146 in the manner previously described, and through overhead conveyor 20 and trolley 28 move along the path of travel 21 downstream to the next workstation in assembly line 316 (not back to workstation 314A as described above). In one example as shown in
Although workstation 314A and 314B are described as being manual and automated assembly setups and functions, it is understood that the workstations may be reversed in order, for example automated assembly first then manual operations, or may be a combination of both manual and automated operations in the same workstation depending on the application. It is further understood that different operations may occur than those described. For example, automated robots (not shown) may grasp and position workpiece 146 and place them in tooling fixtures in workstation 314A instead of manual operations depending on the application.
An advantage of carrier lift 310 carriers 27A, B and C and workpiece support beam 350 is that support beam 350 may be used to engage workpieces 146 on the support beam 350 underside or lower surface 351 (similar to support beam 36 previously described) or on the support beam 350 upper surface 349. When engaged on lower surface 351, for example as shown in
In the example, a plurality of workpieces 146 are vertically stacked as generally shown. Carrier lift 10, 310 is positioned in the workstation 316 at an upper level 500A or raised position 410 and then lowered through lift mechanism 52, 352 to engage the exposed workpiece 146 through, for example, actuation of workpiece engaging devices 147 as generally described above. Carrier 10, 310 is then raised by lift mechanism 52, 352 as described above and moved to the next workstation down the assembly line path of travel 21. Alternately, carrier 10, 310 may be used to place or deposit workpieces 146 into the stacker 510 and cradle 516 in a similar manner as placing workpieces in a fixture, for example trunnion fixture 148, as described above.
As the exposed workpiece 146 in stacker 510 may be at different heights depending on the current capacity of stacker 510, sensors or other monitoring devices may be used to signal a central controller which then calculates the proper amount for carrier 10, 310 and support beam 36, 350 to lower into tooling area 420 to properly engage the exposed workpiece 146. Alternately, stacker 510 may include devices which automatically position the highest or exposed workpiece 146 at a predetermined and known height so that carrier lift 10, 310 may be lowered to the same lowered position and engage workpiece 146 at a known height position. Other stacker devices 510, constructions, orientations and operations known by those skilled in the art may be used.
In one example, conveyor 528 operates as a “first-in-first-out” type of system where the workpieces 146 are kept in sequential order in the production assembly sequence. This is useful and advantageous to support the complex assembly build sequences in automotive assembly where, for example, random or short batch build sequences described above are used. The carrier lift 10, 310 device is useful and fully supportive of this sequenced part or component delivery systems described in U.S. Pat. Nos. 8,869,370 and 9,513,625 the entire contents of which are incorporated herein by reference.
In another example of powered conveyor 528 (not shown), a second powered roller transport 528 and pallet 532 is used on the opposite side of carrier lift 10, 310 (to the right of carrier 10, 310 in
In an alternate example, all of the workpieces 23 on the left transport conveyor 528 may be used or engaged and removed by carrier lift 10, 310 before any from a right transport 528 (not shown) is employed and workpieces thereon used or processed. This may be useful in batch build assembly sequences where all of the components on one transport conveyor 528 are for one vehicle body type and another transport 528 may include workpieces 146 for an alternate vehicle type. Other combinations, constructions and orientations of transport conveyors 528 may be used as known by those skilled in the art.
As noted above, carrier lift 10, 310 carriers 27, 27A, B and C and the variously described workstations 314 may include a plurality of sensor devices, for example, vision, optical, laser, pressure and limit-type switches, which all may be in communication with a local and/or central controller as described above in a closed loop, feedback system to continuously monitor, control and send data to and from the carrier 10, 310, so the carrier 10, 310 and assembly line is highly monitored and controlled for present and historical operations data.
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It further understood that the workstation could be a non-assembly or non-manufacturing cell or area, for example a stacker or buffer 510 device, work table 508, or area where workpieces 146 are temporarily stored in fixtures or racks until the workpieces are re-engaged by the carrier 27, 27A-D for further processing or transfer along the assembly line or to another predetermined location or area. For example, the workstation may be a production line buffer wherein workpieces that are in process are temporarily stored or racked, for example cradle 516 in
In an exemplary second step 620 a carrier 27, 27A-D supporting the workpiece 146 is selectively lowered from a raised position to a lowered position in the workstation. In an optional step 625, the carrier positions the workpiece 146 in a fixture, tooling, rack or other device positioned in the workstation, for example trunnion fixture 148, work table 508, cradle 516, or tooling 534, used to support and/or manipulate the workpiece 146 as needed for the predetermined process or processes in the workstation. It is understood that the carrier can be lowered (or raised) and stopped at any point along the carrier vertical axis of travel 370 suitable for the particular workstation or process. In one example (not shown), the carrier 27, 27A-D automatically disengages or releases the workpiece 146 from a workpiece support beam 36, 350 through actuation of one or more workpiece engaging devices 147 connected to the support beam 36, 350 as described above. It is understood that carrier 37, 27A-D may begin at a lowered position and raised to the raised position for further processing.
In one example (not shown) the carrier 27, 27A-D is raised from the lower position away from the exemplary fixture or other device supporting the workpiece to provide clearance for the predetermined process or operation to take place on the workpiece.
In one exemplary step (not shown), a buffer 510, cradle 516 (
In the example, step 630 includes conducting a process on the workpiece. The process or operation may be, for example, welding, brazing, soldering, application of adhesive, riveting, staking, bolting, drilling, machining, polishing and other assembly and/or manufacturing processes, or temporary storage for example in a buffer, known by those skilled in the art (each considered a process or operation as used herein). These processes may be executed by programmable industrial robots (not shown) or other automated or semi-automated devices or manual by an operator.
In an optional step 635 (not shown), opposite to optional step 625, the carrier 27, 27A-C may remove the workpiece 146 from the fixture or other workpiece supporting device. In one example (not shown) described above, the carrier 27, 27A-D will automatically actuate workpiece engaging devices 147 to re-engage or reacquire the workpiece 146 to support beam 36, 350 so that the carrier again supports the workpiece 146. Sensors may be used along with power sources to determine the position of the support beam 36, 350 relative to workpiece 146 in order to actuate the workpiece engaging devices 147 to re-engage or removably connect the support beam 36, 350 to the workpiece 146. It is understood that, depending on the application and assembly process, steps 625 and 635 can be switched. For example, step 625 can be that carrier lift 10, 310 first goes to, for example, a stacker or buffer 510, or a worktable 508, where the workpieces 146 are presently positioned and first engage the workpieces and then removing them (versus carrying workpieces 146 into the workstation and depositing them as first described for step 625 above).
In example step 640, the carrier 27, 27A-D raises the workpiece 146 from the lowered position, for example 416, to a raised position, for example 410, in the workstation. In one step (not shown) a locking mechanism 132, 132A may be actuated to lock or prevent vertical movement of the carrier 27, 27A-D support beam 36, 350 while in a locked position.
In an optional and exemplary step 655, the carrier lift 10, 310 is transferred from the workstation along the assembly line path of travel 21 to the next predetermined workstation or location for further processing or storage. It is understood that the above steps are exemplary and that additional, or fewer, steps, and in different order of sequence, may be used in the manners described above without deviating from the present invention. In one example step not shown, the workstation may include two sequential workstations, for example workstations 314A and B (
All terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.
The above drawings are not necessarily to scale and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present invention. Further, the above descriptions set forth herein are not intended to be exhaustive or otherwise limit or restrict the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description.
The foregoing description relates to what is presently considered to be the most practical embodiment. It is to be understood, however, that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims.