US2204258A

US2204258A - Nibbling machine

Info

Publication number: US2204258A
Application number: US203381A
Authority: US
Inventors: George F Ryan
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1938-04-21
Filing date: 1938-04-21
Publication date: 1940-06-11
Anticipated expiration: 1957-06-11

Description

June 11, 1940. G. F. RYAN NIBBLING momma Filed April 21, 1938 2 Sheets-Sheet 1 June 11, FQYAN 2,204,258

NIBBLING MACHINE Filed April 21, 1938 2 Sheets-Sheet 2 Patented June 11, 1940 UNITED STATES PATENT OFFICE NIBBLING MACHINE Jersey Application April 21, 1938, Serial No. 203,381

10 Claims.

This invention relates to nibbling machines and is herein illustrated as embodied in a nibbling head adapted for use in a machine of the type disclosed in Letters Patent of the United States No. 2,148,506, granted February 28, 1939,

on an application of G. F. Ryan.

In the operation of a machine of this type relative movement is effected between a piece of sheet material and a nibbling head having a rapidly reciprocating tool or punch along a path corresponding to the desired contour of the work piece to be cut from the sheet material. Because of the resistance offered to the punch in case a sheet of metal is being operated upon and'also because of the-high speed of the punch, enough vibration of the latter may be set up to cause a misalinement of the punch and die which, although slight, may be sufiicient to shorten materially the life of the punch and die.

Moreover, because of the high speed at which the punch is operated, it is impracticable to stop the punch between successive operations to facilitate shifting of the work piece and, accordingly, in machines of this type it is desirable to be able to retract the punch from the die and work without requiring the punch to be stopped.

In view of the foregoing, objects of the invention are to provide an improved nibbling head in the operation of which vibration is reduced to a minimum, and to provide improved means for retracting the punch from the die during the continuous operation of the punch.

Accordingly, the invention provides, in accordance with one feature thereof, improved driving means for a reciprocating punch device, this means comprising in the illustrated construction a pair of crankshafts which are rotated at the same velocity in opposite directions so that the lateral vibration which each crank tends to produce is counteracted by the other. Preferably the punch device is also mounted to reciprocate between and equidistant from the crankshafts whereby lateral frictional and driving forces exerted by the cranks on the punch device are equalized and both vibration and lateral bearing pressures of the punch device are minimized.

With a view toward further diminishing vibration in the operation of the illustrated machine, it is provided, in accordance with another feature of the invention, with means for counterbalancing the punch device, this means comprising, as herein illustrated, a plunger which is arranged to be reciprocated oppositely to the punch unit by a pair of cranks on the abovementioned crankshafts which are spaced 180 from the cranks referred to above from which the punch device is driven.

Another object of the invention is attained by the provision ofimproved means associated with a continuously reciprocating punch device for moving the punch between its operative and inoperative positions with respect to the die while the unit is reciprocating. Accordingly, the invention provides, as another feature, a punch device comprising power driven and punch carrying members between which are provided connections having cooperating inclined surfaces arranged to cause relative axial movement between the members when they are rotated relatively to each other. As a result of this construction, a positive driving connection between the members of the tool device is maintained at all times, notwithstanding the movement of the tool away from the work support, and the operator while moving the tool into and out of operative relation to the die is relieved of the shock caused by the tools striking the work. To permit the tool to be moved away from the work support while the tool unit continuously reciprocates, the above-mentioned connections include a nut which, in accordance with another feature of the invention, is provided with teeth extending in the direction of reciprocation 0f the tool device which teeth mesh with a gear throughout the stroke of the device so as to enable the operator, by rotating the gear, to operate the nut at any time while the unit is in motion.

To insure against misalinement of the members of the tool device, they are provided, in accordance with another feature of the invention, with 'alining surfaces which normally are seated on each other.

These and other features of the invention will be apparent from the following description when read in connection with the accompanying drawings and will be pointed out in the claims.

In the drawings,

Fig. 1 is a side elevation partly in section of an illustrative nibbling head in which the invention is embodied, a part of the base of the tool head being broken away;

Fig. 2 is a plan view of a part of the mechanism shown in Fig. 1, parts of the mechanism in this figure having been broken away to show the operating mechanism;

Fig. 3 is an end elevation of the structure shown in Fig. 1, and

Fig. 4 is a sectional side elevation illustrating the punch and die and their mounting.

The frame of the illustrated machine coinprises a base ill and integral therewith an arm [2 overhanging the base, the arm carrying at its outer end a casing l4 having a double row of bearings l6, H3 in which are rotatably mounted

crankshafts

20, 22, respectively. The

crankshafts

20, 22 are arranged to drive, through connections to be described later, a punch device comprising a sleeve member or plunger 24 carrying a punch bar 26 which is mounted to reciprocate vertically within the casing l4 toward and away from the base ill. The punch bar 28 carries at its lower end a punch 28 (Fig. 4) which cooperates with a die 3i! mounted on the base ill to form a series of overlapping holes in a work piece which is continuously moved under the punch 23 while the latter is rapidly reciprocated thereby cutting a profile on the work piece depending upon the direction of its feed movement,.in a manner well understood in this art.

The crankshaits 2Q. 22 are arranged to be driven in opposite directions and at the same speed by interineshing gears 32 and mounted on the

crankshafts

29 and 22, respectively, the latter crankshaft being connected to a suitable source of power such as a motor which is fixed to the. arm l2.

Toward their right-hand ends (Fig. l), the crankshafts 2Q, 22 are provided with cranks 33, 4!), respectively, on which are rotatably mounted blocks Z2, M which are arranged to slide, as the crankshafts are rotated, between the arms oi a :double yoke 45 integral with the plunger '24.

Thus, as the crankshafts 2b and 22. are rotated, the plunger 24 is reoiprocated vertically in bearings 58 carried by the casing M and because of the opposite rotation of the crankshafts and the corresponding opposite movements of the blocks 42, it and their equal spacing from the axis of the plunger 25, lateral forces tending to bend the plunger 2 or to cause it to set up lateral bearing pressures against the bearings 48 are substantially equalized.

Further to insure smoothness in the operation 01' the machine the above punch device comprising the plunger 24 and punch bar 26 is counter balanced by another plunger till arranged to reciprocate idly in bearings 52, mounted in the casing i l, oppositely to the reciprocation of the punch device. The plunger 50, like the plunger is provided with a double yoke 54 between the arms of which

slide blocks

56, 58 which are rotatably mounted on cranks 6t 52 on the crankshafts 2t and 22, respectively, the. crank 60 and the crank 38 being 180 apart and similarly the cranks 62 and it being 180 apart. It will now be understood that the tendency of the punch device to cause the machine to vibrate vertically because of the reciprocation of the punch device, is ollset by. the opposite movement of the plunger 53.

The punch bar 2'6 is normally looked against axial movement with respect to the plunger 2 3 but may be elevated under the control of the operator away from the die 30 in order to permit the work piece to be out along a discontinuous line or to be moved between successive blank forming operations without being operated upon.

To this end, the punch bar 26, at its upper end, is threaded at 64 into a nut 613 to which the bar may be locked in any desired position by a lock nut 68. The. nut 66 is threaded on the plunger at I0 and upon being turned in a clockwise direction (Fig. 2), carries the punch bar 25 downwardly until a conical shoulder l'Z on the upper end of the plunger is engaged by a complemental surface on the nut 65 and another conical shoulder '54 on the lower end of the punch bar 26 is seated against a collar l6 adjustably threaded on the lower end of the plunger 24. When the punch bar 26 and nut 65 are thus seated against the collar l6 and plunger 24, respectively, the punch bar is rigidly held at both ends in axial alinement with the plunger 2t, and the punch 28, during the lower part of its stroke, passes into the die 3t and thus will make a perforation in the work piece on the die.

The extent to which the punch 28 enters the die 38 is controlled by adjusting the position of the collar 16 axially of the plunger iii to which the collar is locked in adjusted position by a set screw ll threaded in the collar and adapted to bear against the plunger. A corresponding adjustment is then made between the punch bar 23 and the nut 66 so that the seating of the latter against the shoulder 12 occurs simultaneously with the engagement of the shoulder M- of the punch bar with the collar it when the punch bar is lowered into its operative position.

However, upon rotating the nut 66 in a counterclockwise direction, the punch bar 26 is elevated Within the plunger 2? to such an extent that the punch 28 throughout its entire stroke is well above the work piece when resting upon the die 3!) thereby permitting the operator to move the work piece without its being engaged by the punch to make a discontinuous cut or to present a fresh area of the work piece to the punch and die for a succeeding blank forming operation.

The punch 28 is thus moved into and out of operative relation with respect to the die 35) at the will of the operator without requiring the machine to be stopped, by swinging a lever TB which is fixed on a segmental gear 89 pivoted on a stud 82 fiXBd in the casing i l, the gear being arranged to mesh with vertical gear teeth formed on the nut 56 so that the drive between the gear Eli and nut 56 is preserved notwithstancb ing the reciprocation. of the punch device, Thus, by swinging the lever 78 in an appropriate di rection, the nut 655 may be operated while the punch device is reciprocating either to raise or to lower the punch bar 26 for the purposes de scribed above, and it is apparent that because of the gear connections between the lever and nut none of the shock resulting from the impact of the punch 28 against the work is transmitted to the operator through the lever 78.

The movement of the lever 78, which results in the retraction of the punch 28 from the die 30, is limited by the engagement of the gear HQ with an adjustable stop screw 33 threaded in a lug 8 3 extending upwardly from the casing It.

The punch 28 (Fig. 4) is reinovably held in the punch bar 26 by a spring collet 85 which is threaded in the lower end of the punch bar 26 and has a conical shoulder 85 which, upon being drawn against a complemental seat on the punch bar 26 causes the punch 25 to be firmly gripped in axial alinement with the punch bar. At its lower end the punch bar 26 is guided by a support 83 fixedly mounted on the casing l4 by means of studs 90 (Fig. 3), the support 88 being provided with a bushing 92 arranged to receive the lower end of the punch bar. In order to prevent the work piece from rising with the punch 28 and also to minimize frictional resistance to the movement of the work piece, there is fixed to the bottom of the support 88 a plate 94 which is perforated to receive a number of balls 96 adapted to engage and roll against the upper surface of the work piece if the latter is moved out of parallelism with the upper surface. of the die 30.

The illustrated die 30 .is so mounted in a holder 58 fixed to the base H] as to permit any of a number of holes 99 in the die to be moved into alinement with the punch 28 when one of them becomes excessively worn. To this end the holes 99 are arranged in the die 30 in a circle which is intercepted by the axis of the punch 28, and the die 30 is adapted to be rotated from one operative position to another, determined by a detent I011 cooperating with recesses in the side of the die 3|], to locate the die with one of its holes 99 directly in line with the punch 28 in which position the die may be locked by a clamp screw I02 which extends across a bifurcated lug I04 projecting from the rear side of the holder 98.

Although the invention has been described herein with reference to a nibbling machine employing a punch and die, it is to be understood that the term punch as used herein is intended to designate any form of marking or indenting tool as well as one adapted to make a perforation, and that the term die is intended to include any form of work support which may be appropriate for use with the type of tool in question.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a nibbling machine, a die, rotatable shafts each having a pair of oppositely disposed cranks, means for rotating said shafts at the same velocity, a punch device connected to one of the cranks of each shaft and mounted to reciprocate toward and away from said die, and an idling plunger for counterbalancing said punch device connected to the other cranks on said shafts.

2. In a nibbling machine, a die, a punch device mounted to reciprocate toward and away from said die, rotatable shafts each having a pair of oppositely disposed cranks, means connecting said shafts whereby one is rotated at the same velocity as and in a direction opposite to that of the other, connections between said punch device and one crank on each of said shafts for causing said punch device to be recipro'cated when said shafts are rotated, and an idling plunger connected to the other cranks of said shafts for counterbalancing said punch device.

3. In a nibbling machine, a die, a punch mounted to reciprocate toward and away from said die, a pair of rotatable shafts having cranks, connections between said shafts for rotating them at the same velocity in opposite directions whereby said cranks are moved alternately toward and away from each other, connections between said cranks and said punch for causing the latter to be reciprocated when the shafts are rotated, an idling plunger, and means for reciprocating said idling plunger at the same frequency as but oppositely to the reciprocation of said punch.

4. In a nibbling machine, a die, a punch device comprising a member mounted for movement toward and away from said die and a punch bar carried by and mounted for movement axially of said member, cooperating surfaces on said bar and member for insuring their axial alinement, and means movable in one direction to seat said surfaces on each other and in another direction to move said bar with respect to said member away from said die.

5. In a nibbling machine, a die, a punch device comprising a plunger mounted to reciprocate toward and away from said die and a punch bar mounted in said plunger for movement axially thereof, cooperating conical surfaces on said bar and plunger for insuring their axial aline- ,ment, and means connecting said bar and plunger movable in one direction to seat said conical surfaces on each other, said means being movable in the opposite direction to move said bar with respect to said plunger away from said die.

6. In a nibbling machine, a die, a punch device comprising a member mounted to reciprocate toward and away from said die and a bar carried by said member adapted to hold a punch, a shoulder on said member adapted to be engaged by said bar thereby to limit movement of .said bar with respect to said member toward said die, and means for moving said bar with respect to said member toward and away from said die comprising gears one of which connects said bar and member.

7. In a nibbling machine, a die, a punch device mounted to reciprocate toward and away from said die, said device comprising a plunger and a punch bar mounted in said plunger for movement axially thereof, means for moving said bar with respect to said plunger away from said die comprising a member fixed on said bar and threaded on said plunger, and means for rotating said member to cause said bar to be retracted from said die.

8. In a nibbling machine, a die, a punch device mounted to reciprocate toward and away; from said die, said device comprising a plunger carrying a bar adapted to hold a punch, means for moving said bar with respect to said plunger toward and away from said die comprising a rotatable nut connecting said bar and plunger, said nut having gear teeth extending in the direction of reciprocation of said device, and a gear mounted and arranged to mesh with the teeth of said nut throughout the stroke of said device whereby said bar may be moved with respect to said plunger while said device is in motion.

9. In a nibbling machine, a die, a punch device comprising a reciprocating member and a punch bar mounted for rotative and axial movement with respect to said member, means for adjusting the punch bar including means slidably engaging said bar for rotating it while it is reciprocating, and connections between said bar and member arranged to utilize the rotative movement of said bar to move it axially into and out of operative relation with respect to said die. I I

10. In a nibbling machine, a die, a reciprocating punch device comprising a plunger and a punch bar mounted for rotative and axial movement with respect to said plunger, said plunger and bar having cooperating inclined surfaces arranged to cause said bar to be moved axially into operative relation to said die when said bar is rotated, said plunger and bar also having shoulders cooperating to limit the axial movement of said bar, and operator controlled means slidably connected to said bar for rotating said bar while said device is reciprocating.

GEORGE F. RYAN.