Accumulating pallet chain-dog conveyor and method of conveying pallets

• US 4,793,261 A
• Filed: 02/11/1987
• Issued: 12/27/1988
• Est. Priority Date: 02/11/1987
• Status: Expired due to Term

• Current Assignee: Dürr Automotion GmbH (Durr AG)
• Original Assignee: Durr Industries, Inc.
• Inventors: Schwaemmle, Kurt W.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/013,482
• Time in Patent Office: 685 Days
• Field of Search: 104/165, 104/172.1, 104/172.3, 104/172.5, 104/229, 104/231, 104/233, 104/249-252, 104/254, 198/803.01, 198/465.1, 198/345
• US Class Current: 104/172.3
• CPC Class Codes: B23Q 7/1457 comprising an impeller or a series of impellers
• CPC Class Codes: B65G 19/02 for articles, e.g. for containers
• CPC Class Codes: B65G 35/06 comprising a load-carrier moving along a path, e.g. a closed path, and adapted to be engaged by any one of a series of traction elements spaced along the path effecting drive at two or more points spaced along the length of an endless conveyor B65G23/32
• CPC Class Codes: B65G 47/261 Accumulating articles

Abstract

An accumulating pallet chain-dog conveyor has spring-biased roller assemblies attached to the pallet underside for frictionally engaging dogs and spacers which are connected to an endless chain. The roller assemblies include rotatable rollers having a plurality of flats for engaging the surfaces of the dogs and spacers. In operation, the pallets are propelled by the dogs which are engaged by the spring-biased rollers. The conveyor includes a pallet stop which halts the forward movement of the pallet at a predetermined position. When the forward movement of the pallet is stopped, the opposed rollers rotate the distance of one flat whereby the dog passes between the rollers in sliding, frictional engagement therewith. Thus, the pallet stops and the endless chain with its attached dogs and spacers continues to move. After the dog passes from between the opposed rollers, the rollers slidingly, frictionally engage a spacer which also passes between the rollers. The sliding, frictional engagement with the dogs and the spacers during the time in which the pallet is stationary due to its engagement with the pallet stop prevents rearward and lateral movement of the pallet. In another aspect, the conveyor includes a pallet-propelling sprocket in synchronous motion with the endless chain and a plurality of sprocket-receiving pins mounted on the underside of the pallet. The conveyor includes a drive course and return course linked by turn courses. As a pallet reaches the end of the drive course or the end of the return course, the pallet-driving sprocket engages the pins whereby the pallet is carried through the turn course.

Claims

1. An accumulating pallet chain-dog conveyor comprising:

a carrier attachment defining a conveyor course;

a pallet adapted to be propelled on said carrier attachment through said conveyor course;

a pallet stop for halting the movement of said pallet through said conveyor course;

an endless propelling means associated with said carrier attachment for propelling said pallet through a portion of conveyor course;

a generally wedge-shaped dog connected to said endless propelling means;

a spacer attached to said endless propelling means;

two pivoting arms attached to the underside of said pallet;

two horizontally opposed rollers for sequentially engaging said dog and said spacer during movement of said endless propelling means and defining a space between said rollers, said rollers each having at least one flat surface for said sequential engagement of said dog and said spacer and one of said rollers being attached to one of said pivoting arms and the other of said rollers being attached to the other of said pivoting arms;

first biasing means in operative relation to said one of said pivoting arms;

second biasing means in operative relation to said other of said pivoting arms, said first and second biasing means for biasing said rollers toward one another such that said dog and said spacer are sequentially, substantially, continuously engaging by said flat surfaces of said rollers;

whereby said rollers engage said dog during operation of said conveyor to propel said pallet through said conveyor course until the movement of said pallet is halted by said pallet stop at which time said biased rollers allow said dog to move through said space, said flats of said rollers being in sliding frictional contact with said dog, whereupon said spacer moves through said space in sliding, frictional contact with said flats of said rollers, imparting a stabilizing force on said pallet.

2. The accumulating pallet chain-dog conveyor recited in claim 1, wherein said rollers are rotatably mounted to said pivoting arms.

3. The accumulating pallet chain-dog conveyor recited in claim 1, wherein said first and second biasing means each include a spring contacting said pivoting arms.

4. The accumulating pallet chain-dog conveyor recited in claim 1, wherein said endless propelling means includes and endless chain to which said dog and said spacer are attached.

5. The accumulating pallet chain-dog conveyor recited in claim 1, wherein said rollers are hexagonal in shape.

6. The accumulating pallet chain-dog conveyor recited in claim 1, wherein said rollers are octagonal in shape.

7. The accumulating pallet chain-dog conveyor recited in claim 1, wherein said carrier attachment is a track and wherein said pallet includes wheels.

8. The accumulating pallet chain-dog conveyor recited in claim 1, wherein said conveyor course includes a vertical turn course and further including a rotating pallet-propelling sprocket assembly for propelling said pallet through said turn course, and a pin assembly mounted on the underside of said pallet, said pin assembly and said sprocket assembly being adapted to mesh with one another such that said pallet is propelled by said sprocket assembly through said turn course.

9. The accumulating pallet chain-dog conveyor recited in claim 8, further including a first housing attached to the underside of said pallet for housing a portion of said one of said pivoting arms, said first housing having a pinmount portion, and a second housing attached to the underside of said pallet for housing a portion of said second of said pivoting arms, said second housing having a pin-mount portion, and wherein said pin assembly includes at least two pins mounted on the pin-mount portion of said first housing and at least two pins mounted on the pin-mount portion of said second housing and wherein said sprocket assembly includes first and second sprockets such that as said pallet reaches said turn course portion of said conveyor course said first and second sprockets mesh with said pins on said first and second housings whereby said pallet is propelled through said turn course.

10. The accumulating pallet chain-dog conveyor recited in claim 8, further including four pin-housings attached to the underside of said pallet, and wherein said sprocket assembly includes two sprockets and wherein said pin assembly includes at least two pins mounted on each of said pin-housings, the relative positions of said pin-housings and said sprockets being such that as said pallet moves to the beginning of said turn course, said sprockets engage said pins to propel said pallet through said turn course.

11. A method of conveyance employing the following:

a conveyor having a carrier attachment defining a conveyor course;

a pallet adapted to be propelled on said carrier attachment through said conveyor course;

a pallet stop for halting the movement of said pallet through said conveyor course;

and endless propelling means associated with said carrier attachment for propelling said pallet through a portion of said conveyor course;

a generally wedge-shaped dog connected to said endless propelling means;

a spacer attached to said endless propelling means;

two pivoting arms attached to the underside of said pallet;

two horizontally opposed rollers for sequentially engaging said dog and said spacer during movement of said endless propelling means and defining a space between said rollers, said rollers each having at least one flat surface for said sequential engagement of said dog and said spacer and one of said rollers being attached to one of said pivoting arms and the other of said rollers being attached to the other of said pivoting arms;

first biasing means in operative relation to said one of said pivoting arms; and

second biasing means in operative relation to said other of said pivoting arms, said first and second biasing means for biasing said rollers toward one another such that said dog and said spacer are sequentially, substantially, continuously engaging by said flat surfaces of said rollers;

said method comprising the steps of;

propelling said pallet at least partially through said conveyor course by engaging said dog with said rollers whereby said pallet is propelled along said carrier attachment;

stopping the movement of said pallet through said conveyor course using said pallet stop, whereby said rollers slidingly frictionally engage said dog and subsequently said spacer to stabilize said pallet to prevent rearward and lateral movement of said pallet on said carrier attachment.