US2021138A - Machine for operating upon sheet metal - Google Patents

Description

NOV; 1935. M. H. BA LLARD ETAL 7 3 MACHINE FOR OPERATING UPON SHEET METAL Filed June 29, 1951 e Sheets-Sheet 1 Fig.1.

, JAM/ENTER.

gg mml @v, 19, 1935. M. H.- BALLARD ET'AL R 2,021,138

I MACHINE FOR OPERATING UPON SHEET METAL Filed June 29, 1951 Sheets-Sheet 2 Nov- 1935- i M. H. BALLARD ETIAL 2,021,138

MACHINE FOR OPERATING UPON SHEET METAL Filed June 29, 1951 6 Sheets-Sheet 3 Nov. 19, 1935. BALLARD r AL 2,021,138

MACHINE FOR OPERATING UPON SHEET METAL Filed June 29, 1931 6 Sheets-Sheet 4 O 1935- M. H. BALLARD EI'AL. A ,0 8

MACHINE FOR OPERATING UPON SHEET METAL Filed June 29, 1931 6 Sheets-Sheet 5 WW FwnmwhW NOV W, 1935. i M. H. BALLARD ET AL 2,021,133

MACHINE FOR OPERATING UPON SHEET METAL Filed June 29, 1931 6 Sheets-Sheet 6 Axis of I Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE MACHINE FOR 0111:]

RATING UPON SHEET ETAL chinery Corporation, ration of New Jersey Paterson, N. J., a corpo- Application June 29, 1931, Serial No. 547,546

3 Claims.

This invention relates to machines for operating upon sheet material and is herein illustrated as embodied in a press of the type commonly known as a clicking machine, such as that disclosed in United States Letters Patent No. 921,503, granted May 11, 1909, upon an application filed in the name of Arthur Bates, and illustrating a machine comprising a work-supporting bed, a reciprocating post, and a presser arm extending laterally from the post and movable therewith toward and away from the cutting bed to force dies through sheet material positioned upon the bed, thereby to form blanks. Various features of the invention disclosed but not claimed herein constitute the subject-matter of applications for United States Letters Patent, Serial No.

692,513, filed October 6, 1933, in the name of Milton H. Ballard, Serial No. 751,030, filed November 1, 1934, in the names of Milton H. Ballard and Donald G. McLean, and Serial No. 755,685, filed December 3, 1934, filed in the names of said Ballard and McLean.

It is an object of the present invention to provide an improved machine of the type referred to which, without sacrificing the characteristic advantages of such machines heretofore in use, will be so constructed and arranged that increased economy in the cutting of blanks will be effected and that the performance of operations by use of the machine as well as the adjustment and servicing of the parts thereof will be facilitated.

To this end, the invention provides a machine of the afore-mentioned type having a frame, and a cutting bed mounted for movement in the frame, together with mechanism for adjusting the position of the bed heightwise of the frame comprising a shaft having a rack, and pawl normally operative to engage the rack to prevent rotation of the shaft, a lever for rotating the shaft, and means carried by the lever for releasing the pawl. This construction is advantageous in that it provides readily operable means for rapidly adjusting the position of the cutting bed relatively to the frame and for retaining the bed in adjusted position during operations of the machine.

The invention in its various aspects is disclosed in the following detailed description and in the accompanying drawings and is pointed out in the claims.

In the drawings:

Fig. 1 is a side elevation of a machine illustrating one embodiment of the invention;

Fig. 2 is a front elevation of the machine with certain parts thereof shown in cross-section;

Fig. 3 is a cross section taken along line III-III of Fig. 2 illustrating the mechanism for adjusting the height of the bed;

Fig. 4 is a view taken along the line IV-IV of Fig. 2 and illustrates details of the bed-locking mechanism;

Fig. 5 is a plan view of the upper end of the frame showing the upper bearing for the post;

Fig. 6 is a cross sectional view taken along lines VI-VI of Fig. 5; v

Fig. 7 is a side view partly in section illustrating the clutch-controlling mechanism;

Fig. 8 is a side elevation partly in section illustrating the motor drive mechanism;

Fig. 9 is a cross-section taken through the lower portion of the motor bracket showing details of the bracket-locking device;

Fig. 10 is a detail view of a part of the bracketlocking device; and

Figs. 11, 12, 13, and 14 are diagrammatic views illustrating the operation of the presser member and cutting bed.

As illustrated in Figs. 1 and 2 of the drawings, the machine comprises a C-shaped frame 10 upon one side of which is slidably mounted a hollow upright post l2 to which is secured a presser member or arm [4 arranged for co-operation with a second presser member, in the form of a cutting bed l6 mounted upon the opposite side of the frame, to apply pressure to work, such as leather or other sheet material, positioned upon the bed. As is customary in machines of this type, the post I2 is movable angularly about its axis so that the presser arm 14 secured thereto can be moved over the bed It about the axis of the post, for example, into operative position relatively to a freely movable cutting die located upon the work. The post is arranged to be reciprocated vertically by a connecting rod 18 operatively connected to an eccentric 2| upon a rotary shaft 20 which is controlled by a onerevolution clutch 22 adapted to cause engagement of the shaft 20 with a fly-wheel 24. Re-

ciprocation of the post l2 results in movement of blank.

The presser arm M comprises an integral casting located substantially entirely upon one side of the post l2 and secured thereto by clamping members 26. The arm extends freely over the central portions of the frame it and is of such length that it can be swung into a position in which its flat striking surface 28 overlies any desired portion of the cutting bed. The arm is so designed that its eiiective cross-section increases from its free end to a point near the axis of the post with the result that the stiffness of the arm under load increases as the point of application of the load upon the striking face .28 is brought closer to. the axis of the post l2. Consequently, the maximum deflection ofthe arm under a given load upon the striking face 28 occurs when the load is applied to the extreme outer end of thearm, and the deflection is practically negligible when the same load is applied to the striking face near the axis of the post.

- The body portion of the bed l6 comprises a casting having a flat cutting-block support 35% mounted upon a hollow colulnn 32 which is slidably positioned an enlarged portion 34 of the frame It. The frame portion M is provided with laterally extending ears 36 within which are located bushings 38 which support screw-shafts 4!) extending upwardly substantially parallel to the axis of the column 32 and equally spaced laterally thereof. The upper portion of each of the shafts 48 is screW-threaded at 42 and engages a nut 44 secured by bolts #35 in an opening 46 in the under side of the bed l6, thereby supporting the bed in position above the frame. The support'3fl carries a wooden cutting block G'l substantially coextensive therewith and which is suitably secured thereto by bolts 68 (Fig. 1) which engage clamp' .ing irons 5B of the block. The forward portions of the bed it including the block 31 are located close to the plane of the axes of the-'screw-shafts 3%, but the rearward portions of the bed extend freely toward the'axis of the post l2 and over- I hang the central portions of the frame it). Thus it will be seen that the forward portions of the bed are substantially rigidly supported against deflection during pressure applying operations whereas the rearward or overhanging portions of the bed are less rigidly supported and are subject to deflection in a downward direction under pressure applied by the presser arm Id. The bed It is provided with stiifening ribs 52 which extend from the column 32 diagonally across the under side of the support 30 to the corners of the bed, and otherribs 54 (Fig. 1) extending from the ribs 52 toward the sides of the block. The ribs 52 a and 54 are so constructed and arranged that the freely extending portion of the bedis stiffened substantially to an equal extent at points equidistant from the axis of the post l2, the effective cross section of the bed increasing in thickness from the side of the bed nearest to the post to a .rigid when theyield of the arm is amaximum and yields increasin ly as the arm .stiffens, with the result that for a given;stroke of the presser arm the pressure applied, for example, to a die supported onthe cutting block 41 .will be substantially constant for any position 'of the die upon the bed. For example, when a die is positioned upon the block ll near the axis of the supporting column 32 and the presser arm is brought into position in which it overlaps the die and bed 5 and is reciprocated, the arm is engaged near its outer end and, under load, is subjected substantially to its maximum deflection whereas the bed 56 remains substantially rigid. On'theother hand, if a die is placed on the cutting block adja- 10 cent to its inner edge, the bed it, under load, is subjected to substantially its maximum deflection whereas thepresser arm id is engaged near the axis of the post [Zand consequently is subject to slight deflection only. Thus, for various 15 positions of a die along the cutting bed at different distances from the axis of the post, the deflections under forces applied to the presser arm and bed during operation of the machine tend to balance each other, that is, the total dis- 20 placement of the members engaging opposite sides of the die tends to remain constant. Furthermore, if a die is successively located on the cutting block at different pointsequi-distant from the axis of the post, in which positions the die 25 will be engaged by the same portion of the presser arm, the successive deflections of the-bed and arm will be substantially the same. Consequently, the sum of the deflections of the portions of the arm and bed engaging the die will be sub- 30 stantially the same for any position of the die upon the cutting block. The pressure applied to the die and consequently the penetration of the die into the cutting block will therefore be substantially the same for all positions of the die 35' ranged forrotation by a hand-wheeltZ. The

shaft it extends through openings 64 in the frame. portion 34 and through slots 66 in the column tE, the slots 66 being elongated to provide clearance for the shaft as the column is moved 5() up or down with the bed. Rotation of .the handwheel 62 in a counterclockwise direction results casting relatively to the arm 54, means is provided for adjusting the shaftfiu relatively to one a of the worms. To this end, the operative connection between the worm 58 and the shaft, 59 comprises a collar. 63 which, surrounds the outer end 60 of the shaft 65 and is'loosely coupled to the worm 58' by interlocking projections 6!. The collar is secured to the shaft 68 by a pin 1'0 which can be inserted in any oneofseveral openings 12 in the end of the shaft. or in correcting the setting of the bed, the bed is leveled by turning shaft 60, causing worm 59 and gear 56 in mesh therewith to raise or lower the right side of the bed 28, the collar 83 being disconnected from the wormed at this time so that 70 a the worm will not be effective to vary theposition of the left side of the bed. The collar 58 is then moved alongthe shaft until thejprojections 61' of the shaft 55 and the worm fat interengage, and the pin H] is inserted'in the nearest hole 12, thus In assembling the machine 5 p its original position, being guided by the inner wall of the wedge IZB so that the setting of the cap is not lost. To provide for taking up the cap bearing upon wear on the walls of the opening I M, the rear end of the cap is provided with a downwardly projecting ear I34 (Figs. 1 and 5) through which extendsa set-screw I36 adapted to engage the frame It. To take up the wear from the cap the set-screw is turned in a clockwise direction with the result that the cap is pulled rearwardly a sufficient amount to compensate for the wear, it being only necessary to loosen the bolts I32 and set-screw ltd prior to adjusting the cap.

The drive shaft 28 is arranged to be operatively connected at the will of the operator to a flywheel 24 (Figs. 1 and '7) driven by a motor MB supported on the frame. The operative connection between the shaft and fly-wheel comprises a one-revolution clutch 22, for example, of the type illustrated in United States Letters Patent No. 1,011,903, granted December 19, 1911, upon an application filed in the name of Arthur Bates, said clutch including a spring-pressed bolt I42 operation of which controls the clutch. The clutch is operated by means of a handle I44 mounted on the presser arm Id and arranged to engage a lever Hit which has a forked end I48 making engagement with a link I563 which is pivoted at 52 on the frame and has a rearwardly extending portion ltd to which is connected a link 455. The link IE6 at its lower end is pivotally connected to a link I58 loosely carried on a stud I66. The stud it also carries a link I62 extending into position for engaging the clutch bolt I 52 normally to hold it in the position in which the shaft 2t and fly-wheel 24 are disconnected. For raising the link I82 to permit movement of the bolt M2 in effecting operation of the clutch, the link IE2 carries a latch 96 i pivoted thereto and having a plate 86 normally arranged in position to be engaged by a plate 56? on the link E58 upon depression of the starting handle I44. Such operation results in the raising of the link I52 to effect operation of the clutch to cause engagement of the fly-wheel and shaft. The latch IE4 is provided with a tail portion I68 which is arranged to be engaged by a cam we on the flywheel shortly after the latter commences to rotate, said cam being effective to rotate the latch I66 to release the link lfis'permitting a spring III to force the link E62 back into position to disengage the bolt I42 at the end of a single revolution of the shaft.

The motor M8 is controlled by mechanism indicated generally by reference character I12 at the top of the frame IE3, this mechanism being operated by a hand lever i'i l pivoted on the frame at H5 and having a switch button I78 effective when the lever i'id is moved forwardly to close the motor circuit. The lever I'M is held in operative or inoperative position as the case may be by a spring-pressed plunger I8 carried by the frame and adapted to extend inwardly into engagement with a portion I32 of the lever I14 to retain it in the position to which it has been moved.

In order to prevent tripping of the clutch lever @522 when the power is off, which might result in inju y to an operator or in damage to the machine or to the work when the power is later turned on, the latch i6 5 is arranged to be held in inoperative position when the motor circuit is open. To this end, the tail portion of the latch ltd is provided with a projection I85 adapted to be engaged by a rocker arm I36 pivoted at I83 on the frame and operatively connected to the link I14 by a rod I90. When the lever I14 is moved rearwardly to open the motor circuit, the rod I98 is depressed with the result that the link I86 is rotated in a counterclockwise direction, 5 engaging the projection I 84 and rotating the latch I64 out of operative position relatively to the link I58. Consequently, as long as the motor circuit is open, depression of the starting handle 14a will result merely in the rotation of lo the link I58 on its shaft E68 without resulting in the tripping of the clutch. Thus, while the starting handle can be moved in such a way that the various parts will not be subjected to strain as they would be if it were held in locked position, no damage will result from its operation.

Preferably, and as shown in Figs. 2 and 8, the motor I40 is supported on a bracket E92 depending from a shaft I96 pivoted in ears let. The fly-wheel 24 is provided with a circular rack I98 which is arranged to engage a pinion 2% on the motor, and has flanges 262 which act as guards to prevent injury to the teeth of the rack I98. These flanges would operate to prevent withdrawal of the fly-wheel unless the pinion and fly-wheel were relatively movable laterally. Consequently, the pivoted motor bracket I92 makes it possible to move the pinion 2% out of the line of movement of the flanges when it is necessary to remove the fly-wheel from the shaft 2e. In order to lock the motor bracket in position with the pinion 260 in mesh with the rack 598, the motor bracket E9? is provided with a depend ing portion 234 having a slot 295 within which is positioned a retaining bar 23% (Figs. 2, 8, 9, and 10). The bar 2&6 is arranged for pivotal movement about a shaft 268 and carries a spring Elli normally operative to force the motor bracket outwardly. The end of the bar 2% is provided with an elongated slot 2l2 within which is lo cated a retaining pin ZI-i and which is supported in the portion 264 of the motor bracket. At one end of the slot M2 the bar 298 is provided with a tapered recess Zlfi adapted to receive a correspondingly tapered portion 2I8 of the pin 2M. The tapered portion ZIS terminates in a shoulder 22!) which, when the bracket I92 is swung outwardly from the frame of the machine, rides upon the outer side of the bar 206, the shoulder being forced into engagement with the bar by a spring 222 which surrounds a reduced end portion 224 of the pin 2M. When it is desired to place the pinion 299 and the rack I98 in mesh, the motor bracket is pushed inwardly and the pin 2 I4 slides along the slot ZIZ until the spring 222 forces the tapered portion 2I8 into the recess fit of the bar, thus locking the bracket in position. The bracket is released by pulling the pin 2M outwardly by means of a handle 22$ thus removing the tapered portion MS from the recess 258, and permitting the spring 2 I to force the bracket outwardly. This construction provides a convenient means whereby the removal of the flywheel for servicing is facilitated.

The operation of the various parts of the machine will be clear from the foregoing description. The operator places sheet material such as leather upon the cutting block 41 forming the upper part of the bed I6 and positions a die upon the work with the cutting edges of the die in contact with the work. The presser arm I4 is then swung about the axis of the post if until the striking face 28 of the arm is positioned over the die. The starting handle I M is then depressed resulting in the engagement of the flying of the bed diflicult.

The bed i5 is locked against downward movement by a pawl 74 (best shown in Fig. 4) mounted on a stud it on the machine frame. The pawl 14 is arranged to engage a circular rack 73 on the inner end of the shaft es and is normally forced into engagement with the rack by a spring 88. A

lever 82 is provided for releasing the pawl I4 when it is desired to vary the position of the bed I6. This lever is loosely mounted on the shaft 6e and is provided with a fiat cam surface 84 and a curved cam surface as adapted to engage a pin 88 onthe pawl I4 upon clockwise rotation of the lever to force the pawl out of engagement with the rack and to maintain it out of engagement as long as the lever 82 is held in a forward position. By moving the lever forwardly through a small angle the cam surface 8 is operative to release the pawl and to hold it out of locking position so that the hand-wheel 52 can be rotated to raise or lower.

the bed Hi heightwise of the arm I i.

In some instances it may be that the machine becomes stalled, due .to improper operation, in which case the presser member M is usually positioned at the lower end of its stroke and exerts tremendous pressure upon the bed I6. When this occurs the parts may be sprung to such an extent that it is difficult to turn the hand-wheel 62. In order to overcome this difficulty, the lever 32 is so arranged that it can be used to apply considerable force to the shaft 6%! to release the bed. To this end, the lever 82 is provided with a pawl 9Q pivoted on a stud 92 carried by the lever and normally forced toward the rack is by a spring 94. However, the pawl is normally maintained out of rack-engaging position by a curved cam surface 96 on the frame which engages a pin 93 on the pawl to hold the pawl in inoperative position. When the lever 82 is rotated outwardly through an angle of about 15, the pin 98 of. the pawl is moved past the cam surface 96 and the spring 94 forces the pawl into engagement with the rack l8, thus providing a connection between the lever and the shaft 89 whereby the shaft can be turned, the pawl I' l being held in inoperative position'by cam The lever 82 is of comparatively great length and consequently considerable force can be applied to the shaft to release the pressure on the released and the bed adjusted to operative posi tion, the lever 82 is swung rearwardly and a flat cam surface it! engages the pin 93 of the pawl 99, removing the pawl from engagement with the rack, and upon further rearward movement of the lever the pin 88 of the pawl I4 drops off the cam surface 8 3 and permits return of the pawl M into engagement with the rack E8 to lock the bed in position. 7 It is to be noted that, when under normal conditions the height of. the bed I6 is to be adjusted, upon a slight forward movement of the lever 82, both pawls I l and 96 are held disengagedfrom the rack I8 by cam surfaces 84 V and res, respectively. The lever 32 is provided with a spring-pressed plunger Id! (Fig. 2) adapted to be engaged by a lug I02 on the machine frame for retaining the lever rearwardlyfln which posi- "tion the bed is locked'rigidly to the frame, or for retaining the lever in slightly rotated position with both pawls released from the rack.

To facilitate the handling of sheet material, the machine is provided with a trough I63 positioned upon the frame between the post I2 and the bed 5 IS, the overhanging portion of the bed providing adequate clearance so that a considerable amount of material can be positioned in the trough out of the way of the operator who may operate upon a portion of the material which is drawn over the inner edges of the block .41 on to its upper surface, the material being conveniently held in position by a clamping device such as clamp 204.

As above stated, the post I2 is slidably mountedi i for reciprocation in the frame. To facilitate the assembly of the post in the machine and to provide for convenient removal of the post when necessary to service it, the bearings for the post are so constructed and arranged that the post can 0 be inserted or removed without disturbing other parts of the machine. To this end, the lower end of the post extends through a bearing formed in a projection Hi5 (Fig. l) on the upper portion of the frame If! and near its upper end is engaged 225 on one side by a. semi-annular bearing W6 which is positioned to take the lateral thrust of the post under the load caused by the operation of the presser arm I4 upon the work. The extreme upper end of the post is reduced in size forming a Q cylindrical member I08. This cylindrical member is engaged by a bearing in the form of a cap 5 iii (Figs. 1, 5, and 6) positioned upon the extreme upper portion of the frame IQ. Since the greater portion of the lateral thrust to which the post is 35 subjected is taken by the hearing I 536, the periphery of the cylindrical member M8 is cut away or relieved on the side remote from the presser memher as indicated by reference character H2 so that it engages the walls of an opening I id in the 0 I I 3 during such times as the presser member is not under load. The advantage of this construction is that the relieving of the member 6&8 will reduce the friction between it and the cap, thus reducing the amount of effort required to turn the. post in moving the presser member over the cutting block 4'! about the axis of the post.

The cap or bearing i In is positioned upon a seat lit which is provided with tapered lateral walls M8, the cap being held in position by of wedges i223 and E22 which are forced between the side walls of a central rib I24 of the cap and the walls H8. In initially positioning the the post and presser member are located with the post in substantially verticalposition by blocking up the presser member. versely and longitudinally on the seat IE6 until the opening I I4 is located over the cylindrical portion I68. The wedges IZS] and IE2 are then driven in and are secured in position respectively by a bolt I26 located in an opening'in the cap and which passes through an elongated opening I28 in the wedge I20, and by a set-screw I36 which passes through the cap and engages the wedge I22. The cap is further'secured in position by bolts I32 which pass through the cap and into the frame Ill. If for any reason the presser member is to be removed, the cap III] is taken off by removing the bolts I32 and withdrawing the wedge I22, the wedge I20 being left in position. Then when the post'is replaced the cap is returned to The cap is adjusted trans- 60 wheel 24 with the shaft 20, thus causing a reciprocation of the post and presser member thereby to force the die through the work and into the cutting block. The operation of the presser arm l4 and the cutting bed I6 is illustrated in further detail by Figs. 11, l2, l3, and 14. These figures are diagrammatic only and very greatly exaggerate the action of the various parts. The full lines in Figs. 11, i2, and 13 indicate the relative positions of the presser arm 44, the cutting bed It and a die 228 at the point in the cycle of operations of the presser member in which the striking face 28 of the presser member is in its lowermost position. In these figures the dotted lines indicated by reference characters 236 represent the position of the presser member 14 upon its initial engagement with the die in each case. Reference characters 232 in Figs. 11 and 12 indicate the position which the presser member would assume at the end of its stroke if the arm were not deflected due to resistance of the die to the movement of the member. Reference character 234 indicates the normal position of the cutting bed I6 when it is not deflected under load. Reference character 236 in Figs. 12 and 13 indicates the position of thecutting bed which it has taken as a result of deflection under load.

In the case illustrated in Fig. 11 it will be observed that the die 228 has been placed upon the cutting block in the vicinity of the axis of the column 32 in which case the resulting deflection of the bed is so small that it can be neglected. At the same time the presser arm I 4 is engaged by the die close to its outer end with the result that the amount of deflection of the arm represented by a is substantially at a maximum. This results in the forcing of the die into the cutting block by a slightly greater amount on the side of the die nearest the axis of the post. In Fig. 12 it will be observed that the die has been located centrally of the cutting block with the result that under load the bed has been deflected by an amount b whereas the arm M which engages the die a considerable distance inwardly of its end has been deflected by an amount a. The deflections referred to are substantially equal and consequently the die has penetrated the cutting block to the same extent throughout the length of the die. In Fig. 13 the die has been placed on the cutting block near its inner edge portion, that is, near the axis of the post and under load the bed has been deflected by a still greater amount I) but, since the die is engaged by the presser arm quite close to the axis of the post, the deflection of the arm is practically negligible. In View of the fact that the bed was deflected substantially to its maximum amount whereas the arm was not appreciably deflected, the penetration of the die will be slightly greater on the portion thereof away from the axis of the post. As illustrated by Fig. 14, letters 0, d, and 6 indicate the approximate position of the die 228 corresponding respectively to its positions shown in Figs. 11, 12, and 13, in which the die is shown in various positions along the central line of the block which passes through the axis of the post. The line 238 represents the contral line of the presser arm it when it is swung laterally over the block to an angle of about 30 relatively to the central line of the block. If the die were placed successively at points d, and e, which are located along the line 2385 at the same distances from the axis of the post respectively as the points 0, d, and e, the effect due to deflections of the arm and bed will be substantially the same as illustrated in Figs. 11, 12, and

13. For example, the deflection of the arm when the die is positioned at 0 will be substantially the same as that when the die is positioned at 0. Since the point 0 is located a greater distance from the axis of the column 32 than the point 0, 5 it might be supposed that the deflection of the bed would be substantially greater when the load is applied at c. This is not the case, however, for the reason that the reinforcing ribs 52 serve to stiffen the bed in directions extending angularly of the central line of the cutting block. As a result of this, the deflection of the bed is approximately the same along an are which has the axis of the post as a center, and, since a die positioned on the block anywhere along the arc engages the 15 presser arm at the same point, the deflection of the arm will likewise be substantially the same with the result that the penetration of the die will be substantially uniform along said arc. In view of all this, it should be apparent that the com pensating deflections of the presser arm and bed produced when the die is placed in different positions anywhere on the cutting-block surface will result insubstantially the same penetration of the die into the cutting block for a given initial position of the bed heightwise of the arm.

In adjusting the height of the presser arm M for a die of given height, the arm is adjusted heightwise of the block through operation of the hand-wheel 62 and its associated mechanism into such position that at the end of the stroke of the presser member the die will be forced into the block a slight distance, in practice, from onesixteenth to three-sixteenths of an inch. The presser arm will then be operative to perform cutting operations with the die in any position on the block and will be effective to perform such operations in a uniform manner over the entire surface of the cutting block.

Having described the invention, what we claim 4 as new and desire to secure by Letters Patent of the United States is:

1. A clicking machine comprising a frame, a post mounted for reciprocation in the frame, a presser arm carried by the post, a cutting bed, means for supporting the bed upon the frame in operative relation to the presser arm comprising a plurality of screw shafts, a transverse shaft, gears connecting the transverse shaft with the screw shafts for rotating the latter to effect adjustment of the bed heightwise of the frame and presser arm, a rack on the transverse shaft, a pawl pivotally mounted on the frame and arranged to engage the rack for locking the bed in adjusted position, a lever loosely mounted on the transverse shaft, a cam on the lever for releasing said pawl upon angular movement of the lever, a second pawl pivotally mounted on the lever, and a cam on the frame normally operable to retain the second-mentioned pawl in inoperative position but operable upon angular movement of the lever to a predetermined extent to permit movement of said pawl into engagement with the rack whereby the lever is effective upon further rotation to cause rotation of the transverse shaft. 2. A clicking machine comprising a frame, a cutting bed carried by the frame, means for adjusting the position of the cutting bed heightwise of the frame comprising a plurality of screw shafts and a transverse shaft for operating the screw shafts, a pawl for locking the transverse shaft in fixed position, a lever loosely mounted on the transverse shaft, a pawl carried by the lever for engaging the shaft whereby the lever can be operated to rotate the shaft, means for normally ment with the shaft and for maintaining the sec- 7 ond-mention'ed pawl out of engagement with the shaft, and. means for releasing the first-meme tioned'pawl and for causing engagement of the second-mentioned pawl with'the shaft upon angular movement of the lever to a predetermined extent whereby the lever. is rendered operative A for turning the transverse shaft.

3. A clicking machine comprising a frame, a

maintainingthe first mentioned navvl in engagecutting bed'mounted for movement'heightwise, of the frame, means for adjusting the position of the bed heightwise of the frame comprising a shaft, a rack on the shaft, a pawl mounted upon the iframe normally operative to engage therack for preventingrotation of the shaft, a lever for rotatingthe shaft, and means carried by the leverfor releasing the pawl. V

MILTON H. BALLARD. DONALD G. McLEAN.

CERTIFICATE OF CORRECTION.

Patent No. 2,021,133. r November E9, 1935.

MILTON H. BALLARD, ET AL.

It is heteby certified that error appears in the above numbered patent requiring correction as foiiows: in the grant and heading to the drawing and specification. title of inventiomior the word "METAL" read MATERIAL; and that the said Letters Patent should he read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of Januuary, A. D. 1936.

Leslie Frazer (Seal) Acting Commissioner of Patents.

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