US2760380A - Machine for intermittently driving an actuating member - Google Patents

Description

Aug. 28, 1956 H. R. HEAVENER MACHINE FOR INTERMITTENTLY DRIVING AN ACTUATING MEMBER 5 Sheets-Sheet 1 Filed May 13, 1953 Aug. 28, 1956 H. R. HEAVENER 2,760,380

MACHINE FOR INTERMITTENTLY DRIVING AN 'ACTUATING MEMBER Filed May 13, 1953 5 SheetsSheet 2 INVENTOR Zen/ fry/@2115? BY ATTORNEY Aug. 28, 1956 H. R. HEAVENER MACHINE FOR INTERMITTENTLY DRIVING AN ACTUATING MEMBER Filed May 13, 1953 5 Sheets-Sheet 5 INVENTQ R /%2rz;q;/Z? Zazwzer ATTORNEY Aug. 28, 1956 H. R. HEAVENER 2,760,380

MACHINE FOR INTERMITTENTLY DRIVING AN ACTUATING MEMBER Filed May 13, 1953 5 Sheets-Sheet 4 INVENTOR 7km V? iaz/e/ er BY a;

ATTORNEY -Sheet 5 Aug4'28, 1956 H. EAVENER MACHINE FOR,INTERMIT TLY DRIVING AN ACTUATING MEMBE Flled May 15, 1953 5 Sheets INVENTOR Z 390 ewe? rzf BY 5 ATTORNEY MACHINE FOR NTLY DRIVINGAN ACTUATING MED BER Application May 13, 1953, Serial No. 354,831 7 Claims. (Cl. 74424.8)

This invention relates to machines for intermittently driving an actuating member of a device such as a blade for severing elongated or continuous strips or pieces of material into predetermined lengths and more particularly to automatic machines for producing metallic strips or tubes of desired lengths for ultimate use in the fabrication of such articles as automobile radiator cores. A machine of this type is disclosed in the U. S. Letters Patent #2,071,584, granted February 23, 1937, in the name of Leo C. Shippy and the present invention constitutes an improvement thereover.

The conventional automobile radiator core comprises a series of preformed strips of a suitable length stacked to aiford a series of spaced water tubes with fins therebetween. These strips, when of a single thickness of material, usually constitute a regular series of zigzag or other similar formations and during quantity production ribbon stock is fed between rolled dies to form deep corrugations, accordion pleats or similar deformations of the sheet material as a preliminary to severing the same into proper lengths. Other strips used in radiator cores are in the form of tubes of rectangular cross section and the formation of such tube material likewise may immediately precede the step of severing the formed material into suitable lengths.

In the machine as disclosed in the aforementioned patent, provision is made for feeding a strip continuously, forming the strip, as it is fed, into a deeply corrugated shape as desired and then severing the formed strip into predetermined and desired lengths. Provision is made in the machine for ensuring the proper lengths to be severed despite a lack of dimensional stability in the stock, i. e., a tendency of pleated sheet stock to vary in its longitudinal dimension when subject to any incidental force or purposely applied force such as the resistance of a knife to feeding of the work. The machine of the patent therefore incorporates an index device associated with a shearing knife for determining or locating the proper length of pleated sheet material to be severed and moving forward that length between successive cutting strokes in timed relation with operation of the forming and severing mechanisms.

A continuously fed piece of tube stock, on the other hand, ordinarily has a stable longitudinal dimension but will are slightly when a section thereof is stopped by a knife in the act of shearing and withdrawing. In handling tubular stock, the longitudinal dimension of the stock being stable, obstruction by the knife blade causes the stock to bend during the severance operation. In this situation the indexing device may be dispensed with while reliance for timing to secure proper Work lengths may be placed on the constant delivery rate of the tube forming instrumentalities.

The aforementioned machine has proved successful and satisfactory in production but, nevertheless, a number of disadvantages have been encountered which should be eliminated. In continuously feeding work material, whether it be in corrugated sheet form or in the form of a atent Q tube, the end of the section to be severed and adjoining the charging side of the knife must momentarily be stopped for the shearing operation as heretofore stated. This stop interval or dwell for a work section is necessarily so short in the interest of production as to require almost instantaneous starting and stopping of the severance or shearing mechanism. In order to protect the shearing mechanism against stresses and strains due to shock and often greater than those the machine parts are able to withstand for substantial periods of time it has heretofore been necessary to lower the productive rate of the machine. Despite lowering of the productive rate to that minimum rate at which the machine would be operable and practicable, difficulties in maintenance have continued, prior to the present invention, because of the repeated shocks imposed on the mechanism leading ultimately to breakage of parts. Any lowering of the machine speed is accompanied by a lowering of quality in the product as a quick cut severs the work cleanly and a slow cut leads to roughness. The clashes of the parts in operating the knife also has given rise to objectionable noise heretofore inherent in the operation of such machines.

It is an object of the present invention to provide an improved machine for severing predetermined lengths from continuously fed work.

Another object is to provide a machine for severing lengths of material from continuously fed sheet metal with a minimum of shock being imposed on the machine.

One other object is to provide a machine for severing predetermined lengths from strip material, the machine having a high production rate.

It is a further object of the invention to provide a smoothly operating machine which is relatively quiet in operation and is adapted to sever lengths from continuously fed work.

Another object is to provide an improved machine for driving an actuating member intermittently and with a minimum of shock.

A feature of the invention resides in a fluid-pressure operated means for performing and controlling the severing operation. Another feature is a fluid-operated cushioning means for absorbing shocks in a mechanism for driving a reciprocating knife. Another feature is the combination of a forming machine for strip material having a continuous feed with a fluid-pressure and mechan ically operated mechanism for reciprocating a knife with relation to said material and at spaced intervals.

These and other important features of the invention and novel combinations of parts will now be described in detail in the specification and then pointed out more particularly in the appended claims.

In the drawings,

Figure 1 is a side elevation of the complete machine illustrating more or less diagrammatically the relation of the various parts thereof;

Figure 2 is an enlarged end elevation of the machine looking toward the left in Figure 1;

Figure 3 is a longitudinal section of a part of the operating mechanism shown on a somewhat larger scale and is taken on line 33 of Figure 2;

Figure 4 is a transverse section taken on the line 44 of Figure 2;

Figure 5 is a section through one of the operating shafts illustrating the trip mechanism forming a part of the drive for the shaft, and the view being taken on line 55 of Figure 2;

Figure 6 is a detailed perspective view of the roller and stop shown in Figure 5 and is drawn to a large scale;

Figure 7 is a transverse sectional view taken on line 7-7 of Figure 3; and

Figure 8 shows in perspective a small portion of the metallic strip as it leaves the forming rolls of the machine.

It is clear from the showing of Figure 8 that the deeply corrugated or pleated strip has little dimensional stability and is easily distorted by any slight force applied to it. Such a strip, as used in automobile radiators, is formed rom brass or copper ribbon and difficulties in handling and severing predetermined lengths of such yielding material are obvious. In treating such material and also tubes of metallic sheet material, the problems have been encountered as above set forth.

By way of example, there is hereinafter described one convenient form of construction in which the present in vention is embodied to eliminate or minimize the disadvantages encountered in the operation of the machine shown in Patent #2,07l,584. The machine herein illustrated is disclosed in the patent referred to except for a novel work severing mechanism which is part of the present invention.

In Figure l, a roll 1 of ribbon stock is shown at the front of the machine with the ribon feeding through the machine to the rear or shearing end. Suitable forming rolls 3 and 4, mounted in side plates 5 and 6 extending upwardly from the bed plate 7, impart to the strip a preliminary undulating form. From the preliminary rolls, the strip passes through an endless or a chain type forming die 8 which, in cooperation with a pressure roll 9 operating under somewhat slower speed than the preliminary forming rolls 3 and 4, reduces the space between the corrugations or pleates 6 (Figure 8) of the work W. A similar endless forming die 10 and companion roll 11 further crowd the fins, pleats or corrugations together and impart to the strip its final undulating shape and also feed the work continuously and toward a work discharge zone wherein a work severing mechanism or reciprocating knife blade is installed intermittently to traverse the work path.

Any suitable gear mechanism may be provided for driving the several forming dies in proper timed relation. Only so much of the gearing as will facilitate understanding of the present invention is shown in the drawings. The main drive shaft is the one on which a pinion 13 is mounted. Gear 12 is an idler mounted on a swinging arm to connect pinion 13 with a cut-off or severance timing gear 16. Gear 16 is a change gear, and the number of teeth in it determines the number of convolutions, pleats or ridges, that are in the strip severed, i. e. the desired length of a corrugated work piece. This is done by means of an indexing device as will appear hereinafter. Gear 14, for the die member 10, is driven through the intermediate gear 15 from a gear not shown on the shaft on which gear 13 is mounted. Associated with the severance timing gear 16 is a sprocket wheel 17 for the chain 18 which is adapted to drive the sprocket 19.

The sprocket 19, as seen in Figure 4, is keyed or otherwise secured to a hollow cylinder or shaft section 20 mounted for rotation in bearings 21 supported in a cylindrical extension 22 on the side wall 5. The bearings 21 are retained in place by means of an annular cap 24, two spacing rings 26 and 28 and an annular shoulder 30 formed on the cylinder 20. The interior of the cylinder 20 is divided into three portions 32, 34, and 36 of different outside diameters for containing a piston 37. The portion 32 is a cylindrical chamber and it is separated from the portion 34 by an annular land 38. The portion 34 is splined or carries longitudinal ribs 35 integral with the cylinder 20, extending from the land 38 and terminating at a shoulder 39 on the cylinder. The land 38 and the ribs 35, together with a flange 40 on an intermediate portion of the piston 37, serve to guide the latter for axial reciprocation within the cylinder 20 as will appear later herein. The flange 40 has a sealing ring 42 recessed within it to form a sliding seal between the cylindrical wall of the flange 40 and the interior wall of the portion or chamber 36. An end portion 44 of the piston 37 extends from the flange 40 and is of a diameter similar to that of that portion of the piston which is slidably received within the land 38 and the ribs 35 of portion- 34. Each of twelve spaces or grooves between adjacent ribs 35 is formed as a raceway snugly to receive two steel balls 46 and a snap ring 56 is employed to retain the balls 46 during assembly. The balls 46 are also adapted to roll in straight raceways 52 formed in one end of the piston 37 and extending half-way towards the flange 40. The ends of the raceways 52 are closed by a flange 54 on a sealing member 56 threaded into the end of the piston 37 and apertured slidably to receive one end of a shaft 60. Sealing material 62 is retained within a groove 64 formed in the member 56 for annular contact with the shaft 60.

The open end of the cylinder 20 is provided with a cover 70 attached thereto by screws 71. The cover 70 has a protuberance or cam 72 on the edge thereof as best seen in Figure 5 and a central opening 74 in the cover is so proportioned as slidably to receive portion 44 of the piston 37. A sealing ring 76 of yieldable material is fitted within a groove in the cover 70 to engage the portion 44 of the piston. On the exterior of the cover 70 and concentric with the shaft 60 is a cover plate 78 retained in position by screws 79. The plate 78 serves to retain an annular lubricating pad 80 in position on the outer side of cover 70.

The shaft 60 is provided with grooves 82 which take the form of a left-hand thread with a triple lead and each thread is cut through one complete turn. These grooves serve as raceways for balls 84 which are also retained in mating grooves 86 formed in the full length of the smallest bore portion in the piston 37. The balls 84 and helical grooves may be termed a screw and nut arrangement insofar as function is concerned.

The shaft 60 is bored through its length as at 88 and is provided with a radial or diametric slot 90 at one end which slot communicates with the bore 88. At the other end of the shaft 60 the bore is enlarged and in threaded connection with a nipple 92 and a coupling 94 which leads to a swivel member and source of fluid pressure not shown. A bearing plug 96 is bolted to the wall 6 of the machine frame and serves as a journal for one end of the shaft 60.

Intermediate its ends the shaft 60 is provided with a crank or eccentric 98 having lightening holes 100 (Figure 3) and affording a bearing for one end of a connecting rod or blade actuating member 102 the cap 104 of which is attached to the rod by means of bolts 106.

The actuating member 102 is pivoted to a reciprocal slide plate bearing against the end wall 112 (Figure 3) of the machine and within a grooved way provided by guide blocks 114 suitably fastened to the end wall. The central part of the sliding plate 110 is provided with an enlarged opening in line with a smaller opening in the end wall 112 through which the formed stock passes. Secured by bolts 115 to the face of the end wall 112 and within the opening of the slide plate 110 are a pair of anvil plates 116 (Figure 3) which provide between them shearing edges for cooperation with the knife blade 118 clamped to the top of the slide plate 110 by studs 120 and a clamping bar 122.

Adjacent the eccentric portion 98 of the shaft 60 is an enlarged cylindrical portion 124 (Figure 5) to which is rigidly clamped two blocks 126 and 128 by means of screws 130. Block 128 is made larger than the block 126 as one end 132 thereof extends sufiiciently to consti-, tute a stop as will further appear.

The shaft 60 is provided with an annular shoulder 134 which is so arranged as to bear against the side of a cam element 136 keyed to the shaft. A thrust bearing 139 is interposed between the opposite side of the cam member 136 and the inner end of the bearing plug 96.

Referring more particularly to Figures 5 and 6, the extended end 132 of the block 128 is arranged to contact the end of a stop plate 142 which is held by means of screws 144 to a bracket 146 pivoted at its upper end on a stud 148 carried by the side wall 5 of the machine frame. The bracket 146 is in the form of a bell crank and the end of a short leg 150 thereof is engaged by one end of a tension spring 152 which serves intermittently to hold the end of the plate 142 in the path of the block 128. The lower end of the spring 152 is retained by a pin 154 extending from the wall 5. The bracket 146 has a downwardly extending section 156 for supporting a pin 158 upon which a roller 160 is journaled. The roller 160 is so positioned as continuously to engage the periphery of the plate 70 by action of the spring 152.

In order to guide the formed work W towards the knife blade 118, use is made of a track comprising in part a flanged table 164 as shown in Figure 3 which extends into the opening in the end plate 112. Cooperating with the table 164 is a hinged pressure plate 166 pivoted on a pin 168 and urged against the upper side of the work W by a tension spring 170 having one terminal hooked around the upper end of the plate 166 and its opposite terminal secured by a set screw 172 to the top of the plate 112.

Mounted on a transverse shaft 174 and projecting upwardly through an opening in the guide table 164 is an indexing wheel device comprising a pair of toothed wheels 176 (Figs. 3 and 7) fastened by screws 178 to the opposite ends of the hub 180 and adapted to engage by means of the wheel teeth within the downwardly opening spaces between succeeding fins or pleats of the formed work W. The indexing wheel device serves to locate the work W in the severance zone and passes a predetermined number of fins for controlling the length of the work portions severed from the strip. For driving the indexing wheel device in timed relation with the work forming rolls the shaft 174 (Figure 7) is provided at one end with a sprocket wheel 182 and is driven by a chain 184 from a gear 188 (Figure 3) on the driving shaft for the endless forming die 10. To transmit the motion from the shaft 174 to the indexing wheel device use is made of a coil spring 190 (Figure 7) secured at one end to a pin 192 carried by the shaft and at its oppoiste end secured by one of the fastening bolts 178 to the indexing wheel and hub assembly. To relieve the spring 190 from overloading, the shaft has keyed thereto a spacer sleeve 194 from which projects a lug 196 to extend between adjacent heads of fastening studs 178, there being sufficient space between the driving lug 196 and the studs to allow the necessary amount of lost motion. The shaft 174 is journaled in two blocks 198 and 200 which are aflixed to the wall 112.

The driving spring 190 is provide to insure a certain amount of relief movement between the shaft and the indexing wheel device and to give the indexing mechanism a certain intermittent motion. In order to insure a clean cut or severance upon operation of the knife blade 118, it is necessary to stop temporarily or delay the feeding of that portion of the work W immediately adjacent the knife blade 118 and during the descent and Withdrawal of the blade despite the fact that feeding of the work W towards the blade 118 is made continuous by the forming wheel 11. For this purpose there is provided a pawl or detent 202 (Figure 3) on a lever 204, which pawl may be raised upwardly under the influence of a compression spring 206 to engage between the teeth of the index wheel device 176. The spring 206 will yield in the event of jamming of the parts. The indexing device is further described in the patent earlier referred to but it is suificient to state herein that the detent 202 is normally out of engagement with the indexing wheel device 176 and that its operating spring 206 is compressed by means of a connecting rod 207 pivoted at 208 to the end of the lever 204. The rod 207 is pivoted at its lower end to one end of a lever 210 the opposite end of which is pivoted at 212 to the wall 6 at a point below the operating shaft 60. The lever 210 is provided with a lug 214 engaging the cam element 136 and the relation of parts is such that when the shaft 60 is held stationary by the positive stop action of the plate 142 the indexing wheel detent 202 is out of engagement with wheel 176. Upon rotation of the shaft 60, the cam 136 allows the lever 210 to swing upwardly and under the influence of the spring 206 the detent 202 is moved into locking engagement with the indexing wheel device 176 for so much of the revolution of the shaft 60 as is necessary to complete the severing operation and withdraw the blade. During this momentary interruption the driving spring 190 (Fig. 7) will wind up but upon release of the indexing mechanism the spring will then immediately move the index mechanism forward to compensate for the delay essential for work severance and in this manner avoid disruptive interference with the feed of the strip of work W from the forming rolls. The indexing device 176, or the toothed periphery thereof entering between the work pleats, is stopped for a severance operation, is then momentarily moved at a rate in excess of the feed rate of the forming dies, and is then slowed down to the same rate as that of the dies until a predetermined or a given length of the work has been fed under the knife blade 118 for the next severing operation.

In severing tubular work, the function of the indexing mechanism is dispensed with either by omitting that mechanism altogether or by providing means for holding it out of engagement with the work.

It may be seen from the above that the indexing device is essential in the combination of parts to make a complete operative machine insofar as the severance of work shown in Figure 8 is concerned.

In regard to the severing mechanism, which is the main feature of the present invention, the operation of the illustrated machine is made more easily understandable by first stating that the piston 37 and the cylinder 20 are adapted to be constantly rotated together by the sprocket 19 at a rate in timed relation to the rate at which the forming dies form and feed the work.

When the proper time for a work severence occurs, i. 6. when a predetermined length of work has passed under the knife blade 118, the cam 72 strikes the roller 160 and swings the plate 142. out of contact with the end 132 of the block 128. The shaft 60 is therefore released and may be rotated in the direction of the arrow shown in Figure 5 upon application of power thereto. Up until the time of release of the shaft 60, the severance knife or blade 118 will be in its raised position and clear of the work path as in Figure 3. The power for rotating the shaft 60 upon the latters release is supplied by compressed air acting upon the piston 37 the air being constantly supplied under pressure through the nipple 92, the bore 88 and the diametrical groove to be effective on the left end of the piston 37 as viewed in Figure 4. The piston 37 and the cylinder 20 rotate together constantly as stated heretofore but when the piston moves axially because of the air pressure, the interaction of the balls 84 in the helical grooves 82 is such as to move or rotate the shaft 68 through one complete revolution. This pneumatic action effects work severance and also withdrawal of the knife 118 from the work path.

During the end or completion of a single revolution of the shaft 60 the piston 20 is gradually stopped or cushioned in its axial motion by entrapment of air within the chamber 36 of the cylinder 20 and defined by the plate 70 and the flange 40 of the piston. The end portion 44 of the piston engages the sealing ring '76, and the trapped air cushions the movement of the piston until the rotation of the shaft 60 becomes almost nil.

The shaft 60 is then positively stopped from rotation by the means shown in Figure 5, i. e., the end of the plate 142 again engaging the extended portion 132 of the block 128. The cylinder 20 and piston 37 continue to rotate and coaction of the ball bearings 84 between the stationary shaft 60 and the rotating piston 37 is such as to force the piston to move lengthwise or axially and to the left as viewed in Figure 4. This movement will be against the fluid pressure which is constantly applied approaches the annularv shoulder 39 of the cylinder 20- the timing of theimachine is such that the ,shaft v69 is againreleased byaction of the cam 72 on theroller 160 and the axial direction of travel of the piston is reversed to initiate the next severance operation,

During the interval in which the shaft 60 is not rotated, time is provided for the piston to return to its initial position against the. fluid pressure and .this permits ,a simultaneous feeding of a predetermined length of work or strip W. under the knife blade 118. if the workis a corrugated strip, as shownin Figure 8, the indexing device of Figure 7 is used to compensate for the effect of the fins, or pleats in crowding or spreading during, severance. If the work is a straight piece or-in the formof a tube, an arc is necessarily formed in the work during the,

severance time and this arc straightens out after the knife is withdrawn-fromthe Work ,path because cf the stiffness inherent in the. Work., Thisisnot a deterrent in.

securing proper length as the feedrate of the forming tools ordies and the time of reciprocation of the, knife blade 118 may be correlated with that end ,in mind.

It will be seen from the above that during theinterval the piston movesv in one direction asmotivated by the fluid pressure, the cutting blade or the knife 118 proceeds through one complete, operative cycle and as the piston 37 is moved in the other direction and against the fluid pressure, the knife blade 118 is heldclear of the work path as the predetermined length of Work, with or without the presence of theindexing device, is fed under the knife. The pneumatic action in driving the severance blade 118 does away With the shocks to the. mechanism heretofore encountered in the use. of the.

earlier machine and the entire machine, utilizing the presentinvention, may be speeded up to secure better work quality-anda higher rate of production andto eliminate difiiculties of machine maintenance. Obviously, the rotatable cylinder and piston arrangement shown may be utilized with advantage to actuate not only a reciprocat-.-

for intermittently stopping rotation of suchshaft, and

means for directing fluid pressure to one end of said cylinder;

2. {A machine. for driving an actuating member comprisinga frame, acylinder journaled in said frame, a piston axially movable Within said cylinder and rotatably locked thereto, a shaft having one end portion journaled in said .pistonand the remaining portion extending from said cylinder and journaled in said frame, balls retained in mating helical grooves formed in the said shaft and piston, means for intermittently stopping rotation of said haft: including; ;a camon said cylinder, and .means. :for.

directing. fluidpressure. tonne endof said cylinder.

3. .A; machineiondriving an actuating member comprising a fraine,.a cylinder .journaled in said frame, a piston axiallvmovablewithin said cylinder andtrotatably. locked:

thereto, ashaftjournaled in-said piston; andextending.

fromasaid cylinder aflange on said piston andarranged tocooperate.:,with said .icylinder. to..formv an air pocket,

balls retained inmating. helical grooves. formed-inthe said shaft; and piston, means for intermittently stopping rotationof such shaft,'and means for directing fluid pres-:- sure .tothe end of saidcylinden oppositely disposedfrom said air pocket.

4.. A. machine. fordriving an actuating member com-- prising aliframe; a :cylinder journaled in said frame, a

piston axially, movable Within said cylinder and rotatably locked thereto,za shaft journaled in said piston andex-h tending afrom said-cylinder, helical driving means arranged to interact between said shaft and piston, means for intermittentlystopping rotation of such shaft, and

means for directing fluid .pressure to one end of said cylinder.;

5. Incombination, an actuating. member, an intermittently .operable' shaft, means arranged to be driven by: said shaftufor operating said actuating member, means for intermittently. holding such shaft against movement, helical. driving means for intermittently actuating said shaft whenzsaid holding means is'ineifective, and means associated with said helical driving means for releasing said holding I means.

6. In combination, an actuating member, an intermittently operable shaft, means arranged to be driven by said. shaft 'for operating. said actuating member, stop means for intermittently holding such .shaft against movement, 'drivingmeans comprising a screw and nut connec' tion for intermittently actuating said shaft when said holding. means is inefiective, and means associated with said driving. means for releasing said holding means.

7. In combination, an actuating member, an intermittently operable"- shaft, means arranged to be driven= by said shaft for operating said actuating rnember,'st op means for intermittently holding such shaft against movement, helical driving means including a screw and nutarrangement for intermittently actuating said shaft whensaid holding means is'ineifective, means associated with said helical-driving means for releasing said holding; means, and a fluid pressure connection to said driving;

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