Machine tool rotary table locking apparatus

• US 5,676,360 A
• Filed: 07/11/1995
• Issued: 10/14/1997
• Est. Priority Date: 07/11/1995
• Status: Expired due to Fees

• Current Assignee: Thermocarbon, Inc.
• Original Assignee: David E. Bajune, John N. Boucher
• Inventors: Boucher, John N., Bajune, David E.
• Primary Examiner(s): Eley, Timothy V.
• Assistant Examiner(s): WILSON, LEE D
• Application Number:
  US08/500,733
• Time in Patent Office: 826 Days
• Field of Search: 451/397, 451/398, 134/153, 134/157, 134/902, 134/25.4, 269/20, 269/57, 269/56, 269/73, 269/71, 188/368, 188/366, 188/71.4, 188/73.2, 74/826, 74/813
• US Class Current: 269/74
• CPC Class Codes: B23Q 1/28 Means for securing sliding members in any desired position
• CPC Class Codes: B23Q 1/52 a single rotating pair
• CPC Class Codes: B23Q 16/105 clamping with a disc brake

Abstract

A rotary table lockdown apparatus made a part of a computer controlled dicing saw holds a table work surface parallel to a reference surface independent of axial misalignment and without rotational movement. The apparatus includes a deflectable disk rotor radially extended from the table within a plane parallel to the reference surface. A piston styled plunger is biased against a top surface of the rotor forcing it into frictional contact with the reference surface for holding the table and thus the work surface in a rigid position for operation on a workpiece removably attached to the work surface. A chamber is pressurized to displace the plunger in a piston-like manner against a top surface of the rotor. A flexible O-ring holds the plunger in sealable contact with chamber walls and with increased pressure in the chamber flexes to permit the displacement of the plunger. Upon release of the pressure, the flexible O-ring pulls the plunger out of contact with the rotor permitting the table to be rotated. To provide further rigidity, a ball bearing assembly operating within a table rotation shaft and bore permits free rotation of the shaft within the bore under chamber ambient pressure conditions. During chamber increased pressure, displacement of the rotor also results in longitudinal displacement of the shaft forcing the ball bearings to bias against opposing shaft and bore race edges preventing axial misalignment of the shaft and thus table work surface.

Claims

1. A rotary table locking apparatus comprising:

a table assembly having a work surface within a table central portion and the assembly further having a peripheral portion hingeably attached to the central portion, the peripheral portion adapted for making frictional contact with a base;

a base having a reference surface for rigidly securing the table peripheral portion; and

clamping means for securing the table assembly peripheral portion to the base reference surface, the clamping means rigidly securing the table to the base when in a clamped position and permitting movement of the table during an unclamped position.

2. The apparatus as recited in claim 1, further comprising:

the base having a bore for receiving a shaft, the bore having a race carried within a bore side wall portion for receiving bearings;

a shaft extending from the table assembly for rotating the table assembly about a longitudinal axis of the shaft, the shaft rotatable within the bore, the shaft having a race for receiving the bearings operating within the races; and

a bearing slidable within the races for providing smooth rotation of the shaft about the axis within the bore, the bearing generally slidable within race center portions for shaft rotation during the clamping means clamped position, the bearing movable to a position biasing against opposing shaft and bore race side portions for providing a frictional force between the shaft and the base and thus further table rigidity.

3. A rotary table locking apparatus comprising:

a table assembly having a rotatable central portion having a work surface, the assembly further having a peripheral portion for communicating with clamping means, the peripheral portion hingeably attached to the central portion;

a base having a reference surface adapted for securing the peripheral portion there to, the base further having a bore for receiving a shaft, the bore having a race within a side wall portion for receiving bearings;

clamping means for removably securing the table assembly peripheral portion to the base reference surface for locking the table assembly in a rigid position during a clamped position thus preventing rotation of the table assembly, the clamping means permitting table assembly rotation during an unclamped position;

a shaft extending from the table assembly and received within the bore for rotating the assembly about a longitudinal axis of the shaft, the shaft having a race positioned for communicating with the bore side wall race through a bearing operating within the races; and

a bearing slidable within the races for providing smooth rotation of the shaft about the axis within the bore, the bearing generally slidable within race center portions for shaft rotation during the unclamped position, the bearing movable to a position biasing diagonally against opposing shaft and bore race sides for providing further table rigidity during the clamped position.

4. The apparatus as recited in claim 3, wherein the clamping means comprises:

the base further having a peripheral portion adjacent the table assembly peripheral portion, the base peripheral portion having a cavity formed by a cavity top wall and cavity side walls, the side walls dimensioned for receiving a plunger element;

a plunger element defined by top, bottom and side surfaces, the plunger element attached to the table assembly peripheral portion along one plunger element side surface, the attaching sufficient for deflecting the plunger element in a direction generally parallel to the shaft axis during the clamped position for holding the plunger element against the base reference surface and rigidly holding the table assembly, the plunger element bottom surface dimensioned for making frictional contact with the table peripheral portion, the plunger element side surfaces positioned for slidable movement along the cavity side walls, the plunger element further having a top wall defining a chamber in combination with the cavity walls; and

a flexible member in sealable contact with the plunger side surfaces and cavity side walls, the flexible member sufficiently flexible for elastically deforming from a first sealable position during a first pressure level within the chamber to a second sealable position during increased pressure within the chamber for placing the plunger element bottom surface in frictional contact with the table peripheral portion top surface thus locking the table in a rigid position, the plunger element retracting from frictional contact with return to the first pressure level within the chamber.

5. A rotary table locking apparatus comprising:

a circular table having a center portion and peripheral portion surrounding the center portion, the table having a top surface for placing a workpiece thereon and an opposing bottom surface having a shaft extending therefrom for rotation of the table about a longitudinal axis of the shaft, the shaft having a cylindrical side wall;

a disk rotor flexibly extended from the table peripheral portion, the rotor hingedly flexible about the table peripheral portion for movement from a position out of contact with a base contact surface for rotation of the table to a position in contact with the base reference surface for locking the rotor against the base reference surface, the rotor having a first surface for making frictional contact with the base reference surface and a second surface for making frictional contact with a plunger surface;

a base having a reference surface for biasing the rotor first surface thereto, the base having a bore for closely receiving the shaft for movement of the shaft within the bore, the bore having a cylindrical side wall for receiving the shaft cylindrical wall, the base having a peripheral portion proximate the table peripheral portion, the base peripheral portion formed for receiving the rotor therein, the base peripheral portion having a cavity opposing the rotor second surface, the cavity having a top wall and side walls, the side walls dimensioned for receiving a plunger therebetween;

a plunger defined by opposing first and second surfaces and opposing side surfaces, the plunger second surface dimensioned for making frictional contact with the disk rotor second surface, the plunger side surfaces positioned for slidable movement along the cavity side walls, the plunger first surface in combination with the cavity top and side walls defining a chamber; and

a flexible member in sealable contact with a plunger side surface and cavity side wall, the flexible member sufficiently flexible for elastically deforming from a first sealable position during a first pressure level within the chamber to a second sealable position during increased pressure within the chamber for biasing the plunger second surface against the rotor second surface for placing the plunger second surface in frictional contact with the rotor second surface and the rotor first surface into frictional contact with the reference surface for locking the rotor and thus the table in a rigid position, the plunger retracting from frictional contact with a return to the first pressure level within the chamber.

6. The apparatus as recited in claim 5, further comprising:

ball bearings dimensioned for freely rotating within a race;

a first arcuate groove within the bore side wall, the first groove within a plane perpendicular to the shaft axis, the first groove having opposing edge portions and a central portion for movement of the ball bearings about the central portion; and

a second arcuate groove within the shaft wall, the second groove opposing the first groove, the second groove having opposing edge portions and a central portion for movement of the ball bearings within the central portion, the first and second arcuate grooves cooperating to form a race for freely receiving the ball bearings for movement within the race, the groove central portions further cooperating to permit free movement of the bearing within central portions during rotation of the shaft within the bore during the first chamber pressure level while the plunger is out of contact with the rotor thus permitting rotation of the table, the groove edge portions cooperating to bias the ball bearings against opposing bore and shaft race edge portions during the chamber increased pressure for providing rigidity between the shaft and bore and thus further rigidity to the table during the flexible member second sealable position.

7. The apparatus as recited in claim 5, further comprising a shaft gear attached to the shaft for rotating the shaft in response to a driven gear communicating with the shaft gear.

8. The apparatus as recited in claim 5, wherein the plunger further comprises a groove within a side wall most distant the axis and the cavity side wall closest the axis having a groove, the plunger and cavity wall grooves dimensioned for receiving the flexible member.

9. The apparatus as recited in claim 5, further comprising a port extending through the base peripheral portion for providing access to the chamber for controlling pressure within the chamber.

10. A rotary table useful with a computer controlled dicing saw, the rotary table comprising:

a table base having a vertical cylindrical bore for receiving a shaft for rotation within a bore side wall, the bore side wall having a first race positioned for communicating with a shaft first wall race through ball bearings operating within the first races, the bore further having a second race positioned for communicating with a shaft second race through ball bearings operating within the second races, the base further having a reference surface within a plan perpendicular to a longitudinal bore axis;

a cylindrical shaft having an axis or rotation coincident with the bore axis for shaft rotation within the bore, the shaft outside wall dimensioned for free rotation along the bore side wall, the shaft extensively within the bore, the shaft having one end extending outward from the bore for attaching to a table;

the shaft wall having a first race positioned proximate a shaft table end for communicating with the bore first side wall race through ball bearings operating within the first races and a second race positioned at an opposing shaft end for communicating with the bore second race through ball bearings operating within the second races;

ball bearings slidable within the races for providing smooth rotation of the shaft about the axis within the bore, the bearings generally slidable within race center portions for shaft rotation during a table unclamped position, the bearings movable to a position biasing against opposing shaft and bore race sides for providing further table rigidity during a table clamped position;

a cylindrical table attached at a table bottom side to the shaft extended end for rotation of the table about the axis of the shaft, the table having an opposing table work surface for placing a workpiece upon the surface, the work surface generally parallel to the reference surface during free rotation of the shaft within the bore;

a circular disk rotor attached along a peripheral portion of the table within a plane parallel to the work surface, the disk hingably attached for movement from a first position distant the base reference surface for free rotation of the shaft and thus table about the axis to a second position wherein the rotor is biased against the reference surface for locking the rotor and pulling the table into a rigid position having the work surface parallel to the reference surface; and

means for biasing the rotor against the reference surface, the biasing sufficient for providing frictional contact between the rotor and reference surface for preventing rotation of the table and further for moving the bearings to the position biased against opposing shaft and bore race sides, thus providing table rigidity for operation on the workpiece attached to the work surface.

11. The table as recited in claim 10, wherein the biasing means comprises:

a ring member attached to the base reference surface, the ring member and reference surface forming an opening for receiving the rotor therein, the ring member further having a cavity extending over the rotor for placing the rotor between the cavity and the reference surface, the cavity defined by a top wall and opposing parallel side walls; and

a plunger slidable within cavity side walls, the plunger having a top surface defining a chamber in combination with the cavity walls, the plunger further having a bottom surface for biasing against the rotor in response to increased pressure within the chamber.

12. The table as recited in claim 11, further comprising:

the ring member cavity side wall proximate the axis having a groove for receiving a ring member O-ring;

the plunger having a side wall distant the axis, the distant side wall having a groove for receiving a rotor O-ring;

a ring member O-ring positioned within the ring member groove; and

a plunger O-ring positioned within the plunger wall groove, the O-rings positioned for making sealable contact with corresponding rotor and surface portions, the O-rings flexing from a first position wherein sealable contact is made at a wall surface portion for each O-ring to a second O-ring twisted position wherein the O-rings maintain sealable contact at their respective surface portions, the O-rings elastically torqued by movement of the plunger resulting from increased pressure within the chamber, the O-rings further returning to their first sealable position with removal of the increased pressure within the chamber.

13. A rotary table locking apparatus comprising:

a table assembly having a rotatable work surface, the assembly further having a peripheral portion hingeably attached thereto;

a base having a surface portion for clamping the table assembly thereto, the base further having a bore for receiving a shaft;

clamping means carried by the base, the clamping means for placing the table assembly peripheral portion in frictional contact with the base for locking the table assembly in a rigid position;

a shaft extending from the table assembly for rotating the table assembly about a longitudinal axis of the shaft, the shaft closely received within the bore for rotation about the axis; and

bearing means carried within the bore for providing rotation of the shaft, and thus the table, about the axis, the bearing means comprising a first race carried by the shaft and a second race carried by the base, the bearing means further comprising a bearing slidable between the first and second races, the bearing generally slidable within race center portions during shaft rotation about the axis for rotating the table assembly, the bearing biasing against first and second race diagonally opposing race portions during longitudinal displacement of the shaft along the axis, the biasing providing sufficient force for rigidly securing the table to the base.

14. The apparatus as recited in claim 13, wherein the bearing comprises a ball bearing, the biasing thus providing a force between each race opposing portion with such force between the base and the shaft extending through the ball bearing center.

15. A rotary table locking apparatus comprising:

a table assembly having a central portion for providing a work surface, the assembly further having a peripheral portion hingeably attached to the central portion;

a base having a surface portion for positioning the table assembly thereto; and

clamping means for clamping the table assembly peripheral portion to the base surface portions, the clamping means locking the table assembly in a rigid position during a clamped position for preventing rotation of the table assembly.

16. The apparatus as recited in claim 15, further comprising:

a shaft extending from the table assembly for rotation of the table assembly about the axis, the base further having a bore for receiving the shaft therein; and

bearing means carried within the bore for providing rotation of the shaft, and thus the table assembly, about the axis, the bearing means comprising a first race carried by the shaft and a second race carried by the base, the bearing means further comprising a bearing slidable between the first and second races, the bearing generally slidable within race center portions during shaft rotation about the axis for rotating the table assembly, the bearing biasing against first and second race diagonally opposing race portions during longitudinal displacement of the shaft along the axis, the biasing providing sufficient force for rigidly securing the table to the base.

17. A rotary table locking apparatus comprising:

a table having a disk rotor hingeably attached along a table peripheral portion;

a shaft extending from the table for rotating the table about a longitudinal axis of the shaft;

a base having a bore for receiving the shaft therein;

clamping means cooperating with the base for securing the table to the base to thereby longitudinally displace the shaft along its axis; and

wherein the clamping means cooperates with the disk rotor for deflecting the disk rotor and placing the rotor in frictional contact with the base for the locking of the table to the base;

bearing means carried within the bore for providing the rotation of the shaft about the axis, the bearing means comprising a first race carried by the shaft and a second race carried by the base, the bearing means further comprising a bearing slidable between the first and second races, the bearing generally slidable within race center portions during shaft rotation about the axis for rotating the table assembly, the bearing operatively biasing against first and second race diagonally opposing race portions during the longitudinal displacement of the shaft along the axis, so that the biasing thereof cooperates with the clamping means for locking the table to the base.