GB2209488A - Positioning apparatus - Google Patents

Abstract

The apparatus can be mounted on a drill table and carries a position sensor 23 on arm 17 which can pivot on axis 18 at a slider which can slide on arm 14 so sensor 23 has linear and arcuate movement. Arm 17 carries table 19 mounting vice 30 for receiving a master template. Sensor 23 can be removed to enable e.g. holes to be drilled in template 22 at positions corresponding to holes in the master template as sensed by stylus 42 in the drill chuck. When the slave template is finished, the master template is removed and the slave template is used to position the main drill in relation to a workpiece held in vice 30 on table 19. <IMAGE>

Description

POSITIONING APPARATUS AND ASTHODS This invention relates to positioning apparatus and methods.

According to the invention positioning apparatus comprises movable means adapted for carrying a workpiece, the means being movable with a linear movement and with angular movement so that a position sensor carried by the means can be moved to a desired position.

The apparatus may comprise a table for supporting a workpiece, means for supporting a template, the position sensor cooperable with a template supported by said supporting means, said sensor being connected to the table, and gas support means for supporting the table during movement of the sensor and table in relation to the template.

The gas may be air.

The position sensor may comprise cam means cooperable with a valve for forming an air cushion beneath the table during said movement.

The position sensor may be carried on an arm connected for pivotal movement with respect to a member which can slide on a rod.

According to another aspect of the invention a method of moving a position sensor over a surface comprises moving the sensor with a linear movement and an arcuate movement.

From another aspect positioning apparatus comprises a table for supporting a workpiece, means for supporting a template, the position sensor cooperable with a template supported by said supporting means, said sensor being connected to the table, and gas support means for supporting the table during movement of the sensor and table in relation to the template.

The invention may be performed in various ways and one specific embodiment with possible modifications will now be described by way of example with reference to the accompanying drawings, in which: Fig. l is a side view of a positioning apparatus; Fig. 2 is a plan view of Fig. 1; Fig. 3 is a side view of a drill device; and Fig. 4 is an enlarged view of part of Fig. 1.

A positioning apparatus or jig 10 is in the form of a floating template table. The apparatus has a base 11 secured for example to a machine tool drilling table indicated at 9 by a threaded stud 12 or other clamping device and having secured thereto a base table 13, which in the case shown is rectangular. A rectangular section arm 14a extends from the base 11 and supports clamps 14b holding a light weight circular section rod 14 having a longitudinal axis 15. The arm 14a is secured to the base at spaced positions 14c. A slide 16 can slide on the rod 14 and carries a generally rectangular section arm 17 which can pivot on the slide about vertical axis 18 offset from the axis 15. Secured on the arm 17 is a rectangular table 19. The arm 17 extends with a close fit through a bridge 20 attached to the base table 13 and thus the table 19 is maintained in contact with the table 13.

A mounting 21 is provided on the table 13 at the opposite side to the pivot 18 and is adapted to receive releasably a flat template 22. At the end remote from the pivot 18, the arm 17 carries a plunger assembly 23 forming a position sensor.

The slide 16 includes a linear bearing 24 which is a recirculating ball bearing but could be a bearing of the kind supported by compressed air. The arm 17 and table 19 can thus slide on the rod 14 to give linear movement on the axis 15 and can rotate on the pivot 18 to give arcuate movement. The sensor 23 can thus be moved arcuately, and linearly, in a plane.

The table 19 carries a circular support 80 on which is mounted a vice, chuck or other means 30 for holding a workpiece.

The plunger assembly 23 has a bush 31 which is screw threaded into the arm 17. A plunger 32 which can locate in an aperture 33 in the arm 17 is axially slidable in the bush 33. The plunger 32 is connected to an operating knob 34 having inclined cam face 35. The bush 31 is fixed to the arm 17; parts 32, 34, 35 are removable.

In use, the apparatus is first used to obtain a slave template from a master template.

Thus a master template 40 is secured in the holder 30. The template 40 has been accurately drilled, for example, or marked out at which drilling or other action is to be performed. A fresh plan template 22 is secured in the mount 21 and a drill chuck receives a pointed stylus 42.

The plunger assembly 23 is removed and replaced by a hand-operated drill 45' having a shank 43 received in the aperture 33 in the arm 17 and rotatable by a handle 44. Instead of drill 45' a hand drill with suitable cutter is used.

As the plunger assembly is being removed from the arm 17, the cam 35 first opens a valve 45 in a compressed air circuit 46 connecting a source 47 of compressed air with outlet orifices 48 (including adjustable restrictors 49) which face downwardly beneath the table 19; as the cam 35 leaves the valve 45, the valve 45 closes again and remains closed during preparation of the template into the slave template. Valve 45 moves with the arm 17.

The orifices 48 could be directed upwardly from the table 13.

The circuit 46 includes single banjo fitting 46a and double banjo fitting 46b.

When the valve 45 is open, compressed air is delivered beneath the table 19 to r#ise the table slightly clear of the table 13 and support the table 19 on an air cushion. The restrictors are arranged to give a constant air flow from the orifices which are symmetrically located with respect to a centre axis 49' of the table 19. The air pressure may for example be 10 to 30 lb/square inch (0.7 to 2.1 kilogram per square centimetre).

With the plunger assembly 23 removed, the arm 17 and the slider 16, and table 19, are now moved to bring the drilled or marked points on the master template 40 in succession beneath the stylus point 42 and at each location the drill 45' or other drill can be operated to drill the slave template 22 via bush 31 so that the template 22 is thus formed with a plurality of apertures corresponding in relative positions to those on the master template 40. The slave template 22 may for example be of Tufnol paper laminate which is suitably stable and readily drilled but other materials can be used. During movement of the arm 17 between locations, the valve 45 is manually held open to raise the table 19 during these movements.

It is now possible to use the slave template 22 in the repeated drilling of workpieces in the vice or holder 30. Thus the plunger assembly 23 is replaced in the bush 31 and the master template 40 is replaced by a workpiece to be operated on (holes drilled, reamed, tapped for example). The arm 17 is moved in the two directions of movement (linear, rotary), using slider 16 as required, to bring the plunger 32 successively into the apertures in the slave template 22. In movement of the plunger assembly 23 between apertures, the plunger 32 is raised so that the end 50 rests on the surface 51 of the template 22 and thus cam 35 engages and holds open valve 45 so that during adjustment between apertures the table 19 moves on the low friction air cushion. At the apertures the plunger 32 moves downwards and the cam 35 moves off valve 45 and the valve 45 is closed to remove the air cushion during drilling of the workpiece. Thus a succession ofvworkpieces can each be drilled etc. at 8 plurality of accurately related locations or coordinates.

One, fixed, jaw 30a of the vice 30 may carry an adjustable side stop 30b. The other jaw 30c is carried on an arm 60 screw threaded in a housing 61 on table 19 and connected to a handle 62 which can be rotated to move jaw 30c towards and away from jaw 3Ca. The outer end of handle 62 is biased away from the arm 17 by spring 63 in a housing 64 so that the jaw 30c is urged towards the support 80. The spring 63 extends over a stem secured to arm 17.

The outer periphery of workpiece holder support 80 may have an annular resilient guard 52 (e.g. of rubber or plastics) to protect against turnings etc. produced by the drilling operation.

After use of the slave template the apparatus 10 may be removed from the drilling table 9 and, if it is desired to use the apparatus 10 and the slave template Pgain, it is important when replacing the apparatus 10 on the table 9 that the axis 18 be correctly positioned in relation to the axis of the stylus 42. The following procedure can be adopted.

1. The apparatus 10 is fitted to the drilling machine 9 but is not clamped tightly.

2. A template 22 is fitted to the mount 21, having a single predrilled hole 70.

3. The moving part of apparatus is moved to position plunger 32 in predrilled hole 70.

4. Apparatus 10 is moved as a whole to enable stylus 42 to contact a location recess in the workpiece holder 30.

5. Apparatus 10 is clamped tightly to drilling machine table 9.

6. Apparatus 10 is then used to drill one or more apertures or perform other operations on a workpiece, using a previously formed slave template 22.

The apparatus may for example be used on small bench and pillar drills and provides a convenient and uncottiplicated means for repetitive coordinate movement.

Claims (4)

1. Positioning apparatus comprising movable means adapted for carrying a workpiece, the means being movable with a linear movement and with angular movement so that a position sensor carried by the means can be moved to a desired position.

2. Positioning apparatus as claimed in Claim 1, comprising a table for supporting a workpiece, means for supporting a template, the position sensor cooperable with a template supported by said supporting means, said sensor being connected to the table, and gas support means for supporting the table during movement of the sensor and table in relation to the template.

3. PositionIng apparatus as claimed in Claim# comprising two jaws mounted on said table for holding a workpiece, one jaw being movable towards and away from the other jaw, and means for biassing said one jaw towards said table.

4. Apparatus as claimed in Claim 3, in which the position sensor comprises cam means cooperable with a valve controlling the formation of a gas cushion beneath the movable means during the movement.

4. Positioning apparatus as claimed in Claim 2 or Claim 3, in which the gas is air.

5. Positioning apparatus as claimed in Claim 4, comprising cam means cooperable with a valve for forming an air cushion beneath the table during said movement.

6. Positioning apparatus as claimed in any preceding claim, in which the position sensor is carried on an arm connected for pivotal movement with respect to a member which can slide on a rod.

7. Positioning apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

8. Q method of moving a position sensor over a surface comprising moving the sensor with a linear movement and an arcuate movement.

9. A method of moving a position sensor over a surface substantially as hereinbefore described.

10. Positioning apparatus comprising a table for supporting a workpiece, means for supporting a template, the position sensor cooperable with a template supported by said supporting means, said sensor being connected to the table, and gas support means for supporting the table during movement of the sensor and table in relation to the template.

Ctk I#IS 1. Positioning apparatus comprising means for supporting a template, and movable means for moving a worY#piece support and a position sensor support to move the position sensor support in relation to a template supported in the supporting means, the position sensor support being adapted to receive a tool for operation on the template.

2. Apparatus as claimed in Claim 1, in which the position sensor support is apertured to receive a position sensor or said tool.

3. Apparatus as claimed in Claim 1 or Claim 2, including means for forming a gas support for the movable means during movement of the sensor in relation to the template.