GB2075403A

GB2075403A - Punching apparatus

Info

Publication number: GB2075403A
Application number: GB8015169A
Authority: GB
Original assignee: Burner Systems International Inc
Current assignee: Burner Systems International Inc
Priority date: 1980-05-07
Filing date: 1980-05-07
Publication date: 1981-11-18
Also published as: GB2075403B

Abstract

Punching apparatus for punching a series of longitudinally aligned ports in cylindrical tubing of the type used in gas burners includes a vertically reciprocable punch 26 which is reciprocated in synchronism with longitudinal advancement of a chain 20 secured to a tube holder assembly 12 so that a tube is advanced through a collar 28 in a punch arbor 27 by a predetermined amount for each punching stroke. <IMAGE>

Description

SPECIFICATION Apparatus for punching holes This invention relates to porting apparatus for punching holes in tubes or sheet metal. Such tubes may consist, for example, of cylindrical tubing of the type used in gas burners.

Apparatus of this type is described, for example, in U.S. Patents 1,054,143 1 305,972 2,296,483 3,094,158 3,099,180 3,231,099 3,266,356 3,540,258 3,678,718 3,738,209 3,815,399 In accordance with the present invention there is provided apparatus for punching holes in sheet metal or tubing, the apparatus comprising: a plurality of punch arbors supported side-by-side upon a base, each punch arbor including a reciprocably actuated vertical punch; a plurality of corresponding tube or sheet metal arbors supported side-by-side on a movable holder to engage one end of a tube or sheet being punched within the punch arbor, each punch arbor further including: a tube or sheet receiving means for receiving the tube or sheet being punched and a horizontal guide aligning the tube or sheet arbor with respect to tube or sheet receiving means; first stop means for limiting longitudinal advance of the tube arbor with respect to the punch arbor, second stop means for limiting longitudinal movement of the tube arbor away from the punch arbor; and drive means for incrementing the tube or sheet holder longitudinally with respect to the punch arbors while synchronously reciprocating the punches.

The drive means preferably includes a chain drive secured to the movable tube or sheet holder, a ratchet mechanism for rotating a chain drive sprocket by a predetermined amount for each punching stroke, and means for adjusting the amount by which the ratchet is rotated to thereby adjust the longitudinal spacing between the punched holes.

By way of example only, an embodiment of the invention will now be described with reference to the accompanying drawings in which:~ FIG. 1 is a side elevational view, partially in fragmentary section, showing a vertical punch reciprocally actuated at one end, and a tube arbor longitudinally movably positioned with respect to the punch arbor.

FIG. 2 is an end elevation of the punch arbor, showing the vertical punch reciprocally positioned with respect to the tube collar.

FIG. 3 is a side elevation of the linkage between the press ram crank shaft and the drive sprocket for advancing the drive chain.

FIG. 4 is a fragmentary elevation, partially in section, showing the cam and set screw vertical adjusting means for the tube engaging collar.

FIG. 5 is an enlarged, fragmentary perspective, showing the side-by-side array of four punches and respective tube engaging collars in the punch arbor.

FIG. 6 is a fragmentary side elevation, showing support of one end of the punch arbor support rod 38 within the punch arbor.

FIG. 7 is a fragmentary side elevation, along the lines of FIG. 3, and showing the air cylinder depressing arm 7 so as to urge brake arm 39 against brake hub 40.

FIG. 8 is a fragmentary elevation, along the lines of FIGS. 3 and 7, illustrating the air cylinder raising brake arm 7, so as to disengage brake arm 39.

FIG. 9 is a fragmentary side elevation in partial section, illustrating the termination of tube holder assembly movement, as stop rod 18 engages microswitch trip arm 33.

As illustrated in FIGS. 1, 2 and 5, a stationary punch arbor 27 includes a collar 28 for receiving one end of a tube to be punched, and a vertically reciprocable punch 26 secured to a press ram 24 in a press head. The collar 28 is retained within a holder 29 by a set screw 46. The other end of the tube to be punched is placed over a tube arbor 14 in a movable tube holder assembly 12 and locked into position by tube holding pin 15. The tube holding pin 15 is activated by an air cylinder 16.

A tube is advanced through the punch arbor by driving a sprocket chain 20 which is secured to the tube holder assembly 12 by fastener 13. This movement is synchronized with the reciprocating movement of the punch 26 by a linkage including a connector rod 4. The basic drive comes from a crankshaft 43 (Fig. 2) which is driven by a motor 2.

As illustrated in FIGS. 2 and 3, connector rod 4 is reciprocated by rotation of a journal shaft 3 extending from crnnkshaft 43 of the press head 1.

One end of the rod 4 is adjustably locked in a slot on journal shaft 3 so that the eccentricity can be adjusted to vary the stroke of rod 4. The reciprocation of connecting rod 4 reciprocates an idler arm 42 and thereby pushes an attached ratchet arm 5 into notches or teeth of a ratchet gear 6. Adjusting the stroke of rod 4 adjusts the amount by which gear 6 is rotated for each stroke of punch 26.

The resulting rotary movement of gear 6 is transferred through a ratchet drive shaft 9 to a sprocket drive gear 10 which drives the sprocket chain 20. Accordingly, the distance between the punched holes can be adjusted by adjusting the stroke of connecting rod 4. Alternatively, the size of gear 6 may be changed.

Since press ram 24 is reciprocated at a very high rate, the sprocket chain 20 will be driven at a corresponding high rate. Any loose motion is controlled by a sprocket idler gear 11, as well as by a brake 39 which engages a hub 40 of the gear 6 to eliminate over-advancing of the chain due to the momentum of the chain drive. The brake is actuated by an air cylinder 48, having a conventional air hose 49 feeding system, a conventional bleed off valve 50 and a manual control 51 as illustrated in FIG. 7 and FIG. 8. Using this braking control in the single barrel mode, approximately 500 punching strokes of the punch per minute have been achieved. In the multi-barrel mode, as illustrated in FIG. 5, approximately 200 punching strokes per minute have been achieved.

As illustrated in FIGS. 1 and 9, movement of tube holder assembly 12 is terminated when a stop rod 18 makes contact with a trip arm 33 to actuate a microswitch arm 34 and thereby open an electrical circuit, deactivating an electrical solenoid 36 and disengaging a clutch in the drive to the press head 1. Alternatively, the movement of assembly 12 may be controlled or terminated through suitable electronic sensing devices, such as counters coupled with a proximity switch.

The vertical length or stroke of punch 26 is adjusted by a ball screw 23, which is locked into position by a lock nut 22.

To reduce the depth of the opening obtained by the punching operation, the tube collar holder 29 may be moved downwardly away from the stroke of punch 26 by rotating cam 31, illustrated in FIGS. 2 and 4, so that the holder rests upon -a flat of the cam. Alternatively (or additionally), adjustment stops 32 (FIG. 2) for the tube collar holder 29 may be fore-shortened to provide a lower stopping surface with respect to the vertical stroke of punch 26.

The rotation of cam 31 may be accomplished either by the rod 18 attached to tube holder assembly 12 engaging a cam arm 30 as the tube holder assembly 12 is indexed forward by the sprocket drive chain, or by suitable electronic means, such as a conventional counter coupled with a proximity-switch.

The tube holder assembly 12 is aligned with the tube supporting collar 28 by means of two longitudinally extending guide bars 19 9 which support linear bearings enclosed in the tube holder assembly 12.

Precise orientation of punch 26 with respect to punch arbor 27, and the desired punch or shear clearance, is adjusted by means of fine thread nuts 21 connected to a punch arbor support rod 38.

This is to provide adequate openings for operations performed upon the tubular material.

As illustrated in FIG. 6, punch arbor support rod 38 is secured within punch arbor 27 by means of socket head screw 48.

At the end of a punching cycle, the next tube or sheet of metal is placed in position after brake 39 and ratchet arm 5 have been released by deenergising cylinder 48 as illustrated in FIG. 8. A tube holding pin 15 is actuated by an air cylinder 1 6 synchronously with the brake cylinder 48. With the ratchet arm 5 released, the tube holder assembly 12 can be freely pushed (or moved back) into position while being limited by a back stop 17.

The above apparatus thus utilizes a single chain drive system for horizontal moving of the tube, as press ram 24 is actuated vertically downwardly.

This system enables the punching of as many as 12 ports per longitudinal inch of tubing, a capability which contrasts with the approximate 8 ports per longitudinal inch in conventional devices.

Port size is, of course, controlled by changing the size of the punch. Also, changes in height of the tube collar and vertical stroke length of the punch may be undertaken to vary punch configuration, The apparatus may be used for punching holes, extrusions, and lances in sheet metal and tubing.

Claims

CLAIMS 1. Apparatus for punching holes in sheet metal or tubing, the apparatus comprising: a plurality of punch arbors supported side-by-side upon a base, each punch arbor including a reciprocably actuated vertical punch; a plurality of corresponding tube or sheet metal arbors supported side-by-side on a movable holder to engage one end of a tube or sheet being punched within the punch arbor, each punch arbor further including: a tube or sheet receiving means for receiving the tube or sheet and a horizontal guide aligning the tube or sheet arbor with respect to tube or sheet receiving means; first stop means for limiting -longitudinal advance of the tube arbor with respect to the punch arbor, second stop means for limiting longitudinal movement of the tube arbor away from the punch arbor; and drive means for incrementing the tube or sheet holder longitudinally with respect to the punch arbors while synchronously reciprocating the punches. 2. Apparatus according to Claim 1 in which the second stop means is supported on the horizontal guide. 3. Apparatus according to Claim 1 or Claim 2 in which the first stop means is movable with the holder, and the base includes a switch actuable upon contact with the first stop means to deenergise the drive means. 4. Apparatus according to any one of the preceding claims in which the punch arbor furthér includes a vertical adjustment means for adjusting the height of the tube or sheet receiving means with respect to the vertical punch. 5. Apparatus according to any one of the preceding claims further including punch stroke depth adjusting means for adjusting the vertical depth of punch strokes with respect to the tube or sheet receiving means. 6. Apparatus according to Claim 4 wherein the vertical adjustment means includes an eccentric cam. 7. Apparatus according to Claim 6 wherein the vertical adjustment means further includes a vertically adjustable set screw interposed between the tube or sheet receiving means and said base. 8. Apparatus according to Claim 1 further including a stop means supported upon the base to limit longitudinal movement of the tube or sheet arbor with respect to the punch arbor. 9. Apparatus according to any one of the preceding claims wherein the drive means includes a drive shaft for driving the punches, a chain drive for incrementing the tube or sheet holder, and eccentric cam adjusting means interconnecting the shaft and the chain drive to permit adjustment of the amount by which the chain is incremented for each punching stroke. 10. Apparatus according to Claim 1 and substantially as herein described with reference to the accompanying drawings. New claims or amendments to claims filed on 20 Jan. 198 1. Superseded claims 1-10. New or amended claims:~ CLAIMS

1. Apparatus for punching holes in sheet metal or tubing, the apparatus comprising a vertically reciprocable punch, a tube or sheet receiving means positioned beneath the punch for receiving one end of the tube or sheet to be punched, a movable tube or sheet holder for holding the other end of the tube or sheet, means for aligning the holder horizontally with the receiving means, drive means for incrementing the holder to advance the tube or sheet through the receiving means while synchronously reciprocating the punch, means for limiting the longitudinal advance of the said holder toward the receiving means, and stop means for limiting longitudinal movement of the holder away from the receiving means.

2. Apparatus according to Claim 1, in which the aligning means comprises a horizontal guide member, the stop means being supported on the said member.

3. Apparatus according to Claim 1 or Claim 2, in which the means for limiting the longitudinal advance of the holder includes a longitudinally extending member movable with the holder, and a switch actuable upon contact with the longitudinally extending member to de-energise the drive means.

4. Apparatus according to any one of the preceding Claims further comprising means for adjusting the vertical height of the tube or sheet receiving means with respect to the punch.

5. Apparatus according to any one of the preceding Claims, in which the receiving means includes a collar for circumferentially engaging a tube to be punched and an arbor for internally supporting the tube.

6. Apparatus according to Claim 5 further including means for adjusting the vertical depth of punch strokes with respect to the said collar.

7. Apparatus according to Claim 6, wherein the vertical adjustment means includes an eccentric cam.

8. Apparatus according to Claim 7, wherein the vertical adjustment means further includes a vertically adjustable set screw interposed between the collar and a fixed base.

9. Apparatus according to any one of the preceding Claims, wherein the drive means includes a drive shaft for driving the punch, a chain drive for incrementing the tube or sheet holder, and eccentric cam adjusting means interconnecting the shaft and the chain drive to permit adjustment of the amount by which the chain is incremented for each punching stroke.

10. Apparatus for punching holes in metal tubing, the apparatus comprising a row of vertically reciprocable punches, a plurality of corresponding tube receiving means positioned beneath the respective punches for receiving one end of the tube to be punched, a movable tube holder for engaging the other ends of the respective tubes, means for aligning the holder horizontally with the receiving means, drive means for incrementing the holder to advance the tubes through the respective receiving means while synchronously reciprocating the punches, means for limiting longitudinal advance of the holder toward the receiving means, and stop means for limiting longitudinal movement of the holder away from the receiving means.

11. Apparatus according to Claim 1 and substantially as herein described with reference to the accompanying drawings.