Reconfigurable workholding fixture

• US 6,644,637 B1
• Filed: 09/13/2002
• Issued: 11/11/2003
• Est. Priority Date: 09/13/2002
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Spicer, John P., Shen, Chi-Hung, Agapiou, John Stilianos, Lin, Yhu-Tin, Jones, Gary Lee, Bojda, Phillip A.
• Primary Examiner(s): Wilson, Lee D.
• Application Number:
  US10/243,860
• Time in Patent Office: 424 Days
• Field of Search: 269/152, 269/8, 269/16, 269/289.R, 269/27, 269/24, 269/32
• US Class Current: 269/152
• CPC Class Codes: B25B 5/061 with fluid drive B25B5/087, B25B5/122 take precedence

Abstract

A reconfigurable fixture for workpieces is disclosed. It utilizes a flat surface magnetic chuck with modular workpiece supporting, locating and clamping elements that are carefully located on it and held by magnetic attraction to it. These elements are precisely located to hold the workpiece in spaced relation to the chuck surface. Some locating elements are mechanically fixed to the chuck for securing the workpiece from transverse movement on the chuck surface. Preferably, each of the supporting, locating and clamping members are fixed to separate steel bases for magnetic attraction to the chuck. Each base may also carry its own hydraulic actuator for height adjustment of a support element or for height adjustment and closure of a clamping element. These modular elements can be selected from a storage magazine and located on a chuck by numerically controlled mechanisms.

Claims

1. A workpiece holding fixture comprising:

a chuck plate of ferromagnetic material, said chuck plate having a flat surface,

a guide rail fixed to said chuck plate and at least one workpiece locating post with a workpiece locating surface, said post being attached to said guide rail,

at least one workpiece support member, said support member comprising a post with a workpiece engaging post surface, said post being carried upright on a base of ferromagnetic material, said base being adapted for magnetic attachment to said chuck plate surface at a predetermined location, and

at least one workpiece clamp member comprising a clamp arm carried on an upright post that is carried on a base of ferromagnetic material, said clamp post base being adapted for magnetic attachment to said chuck plate surface at a predetermined location, and one of (i) said chuck plate and (ii) said clamp base and said support base being magnetizable and de-magnetizable on command, whereby

each said support member and each said clamp member is located on said chuck plate surface so that a workpiece can be held by said clamp(s) against said post surface(s) in spaced relation to said chuck plate surface for work on said workpiece.

2. A The workpiece holding fixture as recited in claim 1 in which said workpiece locating surface of said locating post comprises a workpiece locating pin.

3. A workpiece holding fixture comprising:

a chuck plate of ferromagnetic material, said chuck plate having a flat surface and being magnetizable and de-magnetizable on command,

a guide rail fixed to said chuck plate and at least one workpiece locating post with a workpiece locating surface, said post being attached to said guide rail,

at least one workpiece support member, said support member comprising a post with a workpiece engaging post surface, said post being carried upright on a base of ferromagnetic material, said base being adapted for magnetic attachment to said chuck plate surface at a predetermined location, and

at least one workpiece clamp member comprising a clamp arm carried on an upright post that is carried on a base of ferromagnetic material, said clamp post base being adapted for magnetic attachment to said chuck plate surface at a predetermined location, whereby

each said support member and each said clamp member is located on said chuck plate surface so that a workpiece can be held by said clamp(s) against said post surface(s) in spaced relation to said chuck plate surface for work on said workpiece.

4. The workpiece holding fixture as recited in claim 3 which said workpiece locating surface of said locating post comprises a workpiece locating pin.

5. The workpiece holding fixture as recited in claim 4 in which a workpiece support member is a modular hydraulic support member comprising a said base;

a support post of adjustable height, said post comprising a rod slidable in a support member cylinder, said cylinder being fixed at one end to said base and adapted to receive hydraulic fluid for adjusting or maintaining the height of said support post;

a pump for delivery of hydraulic fluid to and from said support member cylinder, said pump being carried by said base; and

said base comprising a fluid channel for transport of said fluid between said pump and said support member cylinder.

6. A The workpiece holding fixture as recited in claim 4 in which a workpiece clamp member is a modular hydraulic clamp member comprising said base;

a clamp arm, said clamp arm being carried on a rod slidable and rotatable in a clamp member cylinder, said cylinder being fixed at one end to said base and adapted to receive hydraulic fluid for rotating and adjusting the position of said rod;

a pump for delivery of hydraulic fluid to and from said clamp member cylinder, said pump being carried by said base; and

said base comprising a fluid channel for transport of said fluid between said pump and said clamp member cylinder.

7. The workpiece holding fixture as recited in claim 3 in which a workpiece support member is a modular hydraulic support member comprising a said base;

a support post of adjustable height, said post comprising a rod slidable in a support member cylinder, said cylinder being fixed at one end to said base and adapted to receive hydraulic fluid for adjusting or maintaining the height of said support post;

a pump for delivery of hydraulic fluid to and from said support member cylinder, said pump being carried by said base; and

said base comprising a fluid channel for transport of said fluid between said pump and said support member cylinder.

8. The workpiece holding fixture as recited in claim 3 in which a workpiece clamp member is a modular hydraulic clamp member comprising said base;

a clamp arm, said clamp arm being carried on a rod slidable and rotatable in a clamp member cylinder, said cylinder being fixed at one end to said base and adapted to receive hydraulic fluid for rotating and adjusting the position of said rod;

a pump for delivery of hydraulic fluid to and from said clamp member cylinder, said pump being carried by said base; and

said base comprising a fluid channel for transport of said fluid between said pump and said clamp member cylinder.

9. A workpiece holding fixture comprising;

a selectively magnetizable and de-magnetizable chuck plate of ferromagnetic material, said chuck plate having a flat surface with x-y coordinates for the magnetic attachment of workpiece supporting, locating and clamping elements;

a guide rail attached to said chuck plate and at least one workpiece locating post with a workpiece locating surface, said post being attached to said guide rail;

at least one workpiece support member, said support member comprising a base of ferromagnetic material, said base being adapted for magnetic attachment to said chuck plate surface at a predetermined x-y coordinate location; and

at least one workpiece clamping member, said clamping member comprising a base of ferromagnetic material, said base being adapted for magnetic attachment to said chuck plate surface at a predetermined x-y coordinate location, a hydraulic pump carried on said base, and a hydraulically actuatable clamping member carried on said base, said base comprising a hydraulic fluid channel between said pump and said clamping member.

10. The workpiece holding fixture as recited in claim 9 in which a workpiece support member comprises a said base, a hydraulic pump carried on said base, and a hydraulically actuatable support member carried on said base, said base comprising a hydraulic fluid channel between said pump and said support member.

11. The workpiece holding fixture as recited in claim 9 in which said workpiece locating surface of said locating post comprises a workpiece locating pin.