US3371569A

US3371569A - Shear machine or the like

Info

Publication number: US3371569A
Authority: US
Inventors: Eugene W Pearson; Rolland A Richardson
Original assignee: Pacific Press and Shear Corp
Current assignee: Pacific Press and Shear Corp
Priority date: 1965-06-28
Filing date: 1965-06-28
Publication date: 1968-03-05
Anticipated expiration: 1985-03-05
Also published as: BE673980A; DE1502917B2; SE335658B; DE1777461A1; NL149728B; NL6600896A; DE1502917A1; DE1502917C3; GB1105060A; JPS517874B1; FR1464251A; SE336079B; JPS5738400B1; SE337155B

Description

March 5, 1968 Filed June 28, 1965 33 E. W. PEARSON ETAL SHEAR MACHINE OR THE LIKE 4 Sheets-Sheet 1v INVE/V TOPS EUGENE H. PEARSON B YROLLA/VD .4. RICHARDSON WAHREMBROSLE/ZCYPHER84/VGL/M ATTORNEYS March 1968 E. w. PEARSON ETAL 3,3

SHEAR MACHINE OR THE LIKE Filed June 28, 1965 4 Sheets-Sheet 5 //V [/5 N T 0R5 EUGENE W- PEARSON ggLLA/VD A./-?/0HARD$O/V WARRE'MBROSLEIKGYPHEREfl/VGLIM ATTORNEYS March 1968 E. w. PEARSON ETAL 3,371,569

SHEAR MACHINE OR THE LIKE Filed June 28, 1965 4 $heets-'-Sheet 4 Q INVENTOR 1 EUGENE W- PEARSON k HOLLAND AR/GHARDSO/V a BY WARREN, BRO$LER,CYPHER8 ANGLIM ATTORNEYS United States Patent M 3,371,569 SHEAR MACHINE OR THE LIKE Eugene W. Pearson, Orinda, and Rolland A. Richardson, Alameda, Calif., assignors to Pacific Press & Shear Corp., a corporation of Illinois Filed June 28, 1965, Ser. No. 467,210 18 Claims. (Cl. 83-582) Our invention relates to shear machines or the like and more particularly to the ram and associated drive means therefor.

Among the objects of our invention are:

(1) To provide a novel and improved shear machine;

(2) To provide a novel and improved shear machine capable of being economically fabricated in small and medium sizes;

(3) To provide a novel and improved shear machine of lightweight construction, capable of duplicating the performance of heavier shear machines of conventional design;

(4) To provide a novel and improved shear machine in which the ram may be readily adjusted angularly to alter the rake angle of the blade carried thereby;

(5) To provide a novel and improved shear machine in which the forces generated by the ram drive means are most effectively employed;

(6) To provide a novel and improved shear machine in which spacing adjustments between blades is readily accomplished, and in a simplified manner.

Additional objects of our invention will be found in the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a front view in elevation of a shear machine embodying the present invention;

FIGURE 2 is an end view in elevation of the machine of FIGURE 1;

FIGURE 3 is a plan view of the machine of FIGURE FIGURE 4 is a view in section taken in the plane 4-4 of FIGURE 3;

FIGURE 5 is a view in section taken through a piston drive assembly of a machine of FIGURE 1;

FIGURES 6, 7 and 8 are views depicting ram backing roller details; and

FIGURE 9 is a schematic diagram of the basic hydraulic drive system involved in the machine of FIG- URE 1.

Referring to the drawings for details of our invention in its preferred form, the same comprises a pair of side housings 3, 5, each having an upper recessed front edge 7, and a lower sloping front edge 9 to receive the mount one end of a work supporting assembly 11.

The work supporting assembly includes a front plate 13 spanning the side housings, and a table 15 welded along the upper edge of the front plate and braced by a plurality of gussets 17 welded into place between the table and the front plate.

Means are provided for supporting the lower blade 21 of the machine, adjacent the rear edge of the work support table 15, and this is accomplished by forming a blade receiving notch in the upper edge of the front plate 13 to receive the blade, the blade being bolted to the front plate, with the bolts made accessible through notches 25 formed in the work support table.

Located somewhat to the rear of and, for the most part, above the elevation of the work support table, is a ram assembly 29 for carrying the upper blade 31 of the machine at a rake angle for cooperation With the lower blade in the shearing of material.

This ram assembly includes a ram 33 having rearward 3,371,569 Patented Mar. 5, 1968 extensions 35 terminating in substantially vertical bearing surfaces 37 provided by slides 39 bolted to the edges of the extensions, the ram 33 being disposed at an angle to such surfaces and in a plane which will substantially intersect the line of cut between blades during a shearing stroke.

Mounted on the inner side of each side housing are bearing engagement means 41 for engaging the substan: tially vertical bearing surfaces 37 associated with the ram, whereby to guide the ram in its vertical movements.

Such bearing engaging means takes the form of a pair of vertically spaced roller brackets 45, each bolted to the side housing and notched to carry a roller 49 on a

shaft

51, 53 respectively.

To normally maintain the ram assembly in sliding con tact With such rollers, we provide means for applying a rearward horizontal component of force to the ram assembly. Our preferred manner of realizing this is to utilize spring means 57, pivotally anchored at one end to the ram assembly and at some other point to a location on the proximate side housing.

Structurally such spring means may take the form of a bracket 61 on the side housing, a rod 63 extending through a hole in the bracket and pivotally connected at one end to a point on the ram assembly. Its opposite end portion carries a spring 65 under compression between a spherical washer 67 adjacent the bracket, and a washer 69 carried on the free end of the rod.

The ram is powered by a pair of hydraulically actuated

piston drive assemblies

75, 77 so disposed as to be capable of applying a vertical component of force to the ram assembly, of sufficient magnitude to produce shearing, and a simultaneous forward horizontal component of force of a magnitude approaching the spreading forces developed between blades during shearing. 1

Each of the piston drive assemblies comprises a pivotal anchor assembly 79 at an end of the ram, including a mounting sleeve or tube 81 afiixed to the ram, with its axis in substantially the plane of the rain, a pressure ring 83 at each end of the mounting sleeve, having a convex spherical surface, and a pressure disc 85 adjacent each of the pressure rings and formed with a concave surface complementary to the convex surface of its associated pressure ring.

A similar pivotal anchor assembly 89 is located at a lower fixed location on the machine, in substantial alignment with the pivotal anchor assembly 79 above.

To the lower one of these pivotal anchor assemblies, is connected the lower end of a cylinder 91 which is provided with an attached rod 93 for this purpose, such rod extending through the pivotal assembly 89 and carrying at its exposed end, a clamping nut 95.

The cylinder 91 carries a drive piston 97 having a piston rod 99 extending through the opposite end of the cylinder, such piston rod connecting to the upper one of the pivotal anchor assemblies by passing therethrough and carrying at its exposed end'a holding nut 101.

Hydraulic fittings 103 at each end of the cylinder provide for flow of liquid into and out of the cylinder for drive purposes.

When thus installed, the piston drive assembly at each end of the machine will be found to lie essentially in the plane of the ram 33, and inasmuch as the plane of the ram Wi-ll intersect substantially the cutting line of the blades during shearing, it follows that the forces exerted on the ram by the piston drive assemblies will be in the plane of the ram, and by reason of the fact that the direction of application of the drive forces to the ram thus lie in the plane of the ram and consequently at an angle to the vertical, the drive piston assemblies as previously indicated, are in position to develop both a vertical force for shearing, and simultaneously therewith, a forward horizontal component of force to resist or diminish any loading placed on the side housings in the opposite direction, namely rearwardly in the horizontal direction.

Until the ram supported blade engages work to be sheared, such rearward horizontal loading would be attributable solely to the pullback springs 65, but the angle of the ram is sufficiently small that the horizontal component in a forward direction developed by the drive assemblies will be insufficient to overcome the pull of the pullback springs, and the ram assembly will maintain engagement with the rollers throughout the stroke of the rain.

As soon as the upper blade engages the work, however, considerable force is developed tending to separate the cooperating blades, and such spreading force, if permitted to act on the ram assembly, would not only place terrific loading on the frame components of the machine and particularly the side housings thereof, but would impair the shearing ability of the blades, and leave burrs along the edge of the work. In shearing stainless steel, it is of particular importance that spreading of the shear blades not be permitted, since they must cut deeper before shearing takes place.

During such shearing portion of the stroke, these spreading forces will induce development of counter or forward horizontal components of force by the piston drive assemblies, and by thus minimizing the transfer of such spreading forces to the frame members, the frame members are thereby not only relieved of the necessity of withstanding the same, but a cleaner cut will be realized.

In analyzing the movement of the ram with respect to the piston drive assemblies which power the same, it will be noted that as the ram descends, the piston drive assemblies will shorten up slightly and will swing rearwardly to a very slight angle about the lower fixed pivot assemblies. Accordingly, if at the start of a shearing operation, the application of driving force to the ram is such as will intersect the line of cut, then by the time the ram reaches the end of its shearing stroke, the piston drive assemblies may be slightly off, perhaps an eighth of an inch or so, with respect to the line of cut.

While this is not a serious matter, the same may be compensated for to maintain drive efficiency, by installing that piston drive assembly which is in proximity to the high end of the upper blade, in a slightly forward offset relationship with respect to that cylinder drive assembly lying in proximity to the lower end of the upper blade. Thus during the initial portion of a shearing operation, that drive cylinder assembly adjacent the lower end of the upper blade will take the greater portion of the shearing load, and the drive force applied to the ram by this piston drive assembly will be in a direction substantially intersecting the line of cut.

As the shearing progresses and the load shifts toward the offset piston drive assembly, the shearing load will be gradually taken over by this offset piston drive assembly, and being that it is trailing the first piston drive assembly in the matter of angular swing toward the rear as the ram descends, it follows that toward the completion of the shearing operation, the force applied to the ram by the offset piston drive assembly will more nearly intersect the line of cut than would otherwise be the case were this piston drive assembly not so offset.

During a shearing operation, as described, the ram may exercise a slight tendency to move laterally in its own plane. In accordance with the present invention, such lateral movement is precluded in a manner utilizing roller friction, thereby minimizing friction loss to a negligible minimum.

Toward this end, a slideway 111 is bolted or otherwise afiixed to the inner surface of each side housing, in line with the rear edge of the proximate rearward extension 35 of the ram assembly, and aroller 113 is mounted on such rearward extension for rolling engagement with such slideway.

In mounting such roller, an opening is provided through the rearward extension and a hole drilled into the edge of such extension at that point, to support a roller shaft 117, on the exposed end of which is mounted the roller in rolling contact with the proximate slideway.

The machine may be provided with conventional type hold-down means for clamping work to the work table in anticipation of a shearing operation, or as we have illustrated in the drawings, the machine may be provided with hold-down means embodying the features of an invention for Hold-Down Means for a Shear Machine or the Like, Ser. No. 373,152, filed June 8, 1964, now Patent No. 3,345,897, in the name of Eugene W. Pearson, wherein the hold-down means may take the form of an inflatable tube 121 afiixed along the lower edge of a back-up member 123 supported above the work table in front of the shearing blades.

In the present embodiment, the back-up member is formed of plate material, and along its lower tube mounting edge, it is provided with a reverse bend 125 to create a horizontal surface to which the hold-down tube may be affixed as with a suitable adhesive, the reverse bend, at each end, also providing means with the aid of a spacer block 127, for bolting the back-up member to the work table, to thus support the back-up member.

At spaced locations just above the reverse bend, the back-up member is provided with a series of windows or openings 129, through which an operator may view the shearing blades and thus afford him the opportunity to adjust the work properly in preparation for shearing.

At each end of the back-up member, a guard may be affixed to enclose the proximate piston rod 99 and upper pivotal assembly 79 with respect to the operator.

In a shear or like machine, the ability to adjust the shearing blades is quite desirable. Two such adjustments are contemplated in the present invention, namely a fixed adjustment to correct for slight deviations between the upper and lower blades, and a spacing adjustment between shearing blades to adjust for the shearing of plate material of different thicknesses.

To correct for existing deviations between blades, we

provide a pair of relatively narrow parallel spaced rigid plates 141, 143, running from one rearward extension of the ram to the opposite one, and welded thereto. At spaced intervals, between these narrow plates are adjustment bolts anchored at one end to the ram and carrying an adjusting nut 147 adjacent each edge of the parallel plates and spanning the same. By judiciously adjusting these nuts, slight deviations of the ram with respect to the lower blade can be eliminated. The adjustment for spacing between the shearing blades is accomplished through a modification in the structure of the lower bearing engaging means at each side of the machine, to incorporate therein an eccentric adjustment of the roller 49. This we accomplish by making the shaft 53, an eccentric shaft wherein the portion 153 on which the roller 49 is mounted, is slightly eccentric to the axis of the journalled ends of the shaft. By angularly adjusting the shaft, a shift in the position of the roller may be realized.

If the angular adjustment of the shaft is such as to cause a forward shift of the roller, the added pressure against the ram assembly will cause the upper shear blade to be adjusted toward the lower blade, while if the adjustment of the eccentric shaft is in the opposite direction, pressure against the ram assembly will be diminished, and the ram assembly will be adjusted in a direction away from the lower blade by the action of the spring means 57, which, as previously indicated, will maintain the ram assembly in sliding contact with the rollers 49.

To affect such adjustment of the lower rollers, the eccentric shaft is caused to extend outwardly beyond the proximate side housing and on the exposed end of such shaft is mounted a manually shiftable index lever 157 carrying a spring biased pin 159 at its end, for selectively engaging any one of a series of index holes 161 provided in the side housing.

In utilizing roller bearing guides for the ram assembly, greasing of the slideways is avoided, and such absence of greasing enables very positive, precise and maintainable adjustments, for a layer of lubricating grease could reach a thickness of the order of .002 of an inch and allowances therefor must be taken into consideration. Such layer thickness will Change with ram operation.

This is a problem to be coped with in a shear of conventional design where the ram slides on fixed ways and a substantial layer of grease on the slideways is a practical requirement. It becomes apparent that precise and maintained spacing adjustment between blades is not realizable in such machine. This problem has been eliminated in the machine of the present invention.

While we have previously stressed the action of the drive assemblies in minimizing the transfer of horizontal blade spreading forces to the side housings, to thereby enable one to minimize the stresses and strains in the side housings which would normally be attributable to such horizontal spreading forces, it is significant to note that by anchoring the piston drive assemblies to a frontal location near the base of the machine, the shearing load is taken at these points, and consequently hardly any of the shearing load is transmitted to upper portions of the side housings.

The importance of this may well be brought into focus by comparison of the machine of the present invention to conventional shear design, wherein the piston drive assemblies are mounted on the upper front edges of the side housings, and the side housings are constructed with a deep throat in each, to provide room for the manipulation of work on the Work table. In such construction, the shear load is transmitted to the upper front corners of the side housings, creating moments in the side housings tending to fracture the same at the throats. This accounts for the fact that the side housings in such a conventional type shear must be of heavy material, with the throat portion of ofttimes reinforced.

In accordance with our present invention, the entire upper front edge of each side housing is recessed, as previously described, this being permitted by the fact that no shearing load is transmitted to this portion of the side housing, and such recessed edge in turn permitting of the angular disposition of the proximate piston drive assembly, whereby the entire shearing load may be transmitted to the pivotal location of anchorage at the lower front edge of the side housing, while at the same time causing such drive assembly to develop the forwardly directed horizontal component tending to neutralize the spreading forces developed between the shear blades during shearing. In fact, the side housings of the machine of the present invention, in effect become more or less mere supporting members for the other components of the machine, as distinguished from stress absorbing members, such as in a conventional type machine.

The piston drive assemblies may be alike and supplied with hydraulic fluid in parallel, though we prefer to connect them in series relationship, whereby the first drive piston assembly 77 becomes the master drive assembly, while the remaining one 75 becomes the slave drive assembly. In this type of drive system, the area of the lower side of the master piston should equal the area of the upper side of the slave piston, in accordance with known practice, to assure in the absence of leakage and temperature differences, normal flow rates to the cylinders such as will produce equal rates of travel at each end of the ram.

Hydraulic fluid is pumped from a tank 165 by means of a pump 167 through a check valve 169 to the piston drive assemblies in series, the pump being coupled to a drive motor 171.

Intermediate the check valve and the piston drive assemblies, is a control valve assembly involving a central section 177 and

adjacent end sections

179, 181, under control of solenoids, 183, respectively, one at each end and adapted to produce shift of the valve assembly in one direction or the other from a neutral or central position, depending on which of the solenoids is energized.

The pump output beyond the check valve is connected by a line 189, directly to the upper end of the master cylinder, while a branch line 191 terminates at the main valve assembly 175 and through the center section connects with a return line 195 to tank. The lower end of the master cylinder is flow connected by an interconnecting line 197 to the upper end of the slave cylinder, while the lower end of the slave cylinder is flow connected by a line 199 to the main valve assembly.

In the central or neutral position of the main valve assembly, the branch line 191 is connected to tank, while the return line 199 from the slave cylinder is blocked off at this valve assembly. Thus, the drive piston assemblies are shorted by the return line 195 to the tank and the machine is without power.

When the solenoid 183, at one end of the main valve assembly, is energized to cause a shift to the right as viewed in the drawings, the return line 199 from the slave cylinder is unblocked and connected to tank, whereby a complete flow circuit is established from the pump back to the tank through the drive piston assemblies in series to produce a work stroke of the ram.

When the other solenoid 185 is energized to cause a shift of the main valve assembly to the far left, not only is the flow in the hydraulic circuit reversed, to lift the pistons and the ram supported thereby, but such flow is supplemented by the resulting discharge from the upper end of the master cylinder, which results in the speeding up of the return stroke of the ram.

In conjunction with this hydraulic system, we have provided a novel and simple rake angle control for the ram, permitting adjustment of the angle which the ram makes with the horizontal, regardless of Whether the machine is idle or in operation. In other words, the adjustment of the rake angle may be effected even while the main valve, and consequently the machine, is adjusted for performing operation on work.

Toward this end we provide a pair of control valve assemblies 211, 213 which may either be push-button operated or solenoid controlled. Each rake angle control valve assembly involves two sections, one 215 to open a circuit and one 217 to close it. One such valve assembly' is flow coupled between the interconnecting line joining the two cylinders and the tank, whereby in one position, it will drain hack to the tank, hydraulic fluid which would otherwise go to the slave piston to drive the same. Under such conditions, the master piston will drive the proximate end of the ram downwardly to effect an increase in the rake angle of the ram.

The other rake angle control valve assembly is coupled between the interconnecting flow line and the pressure side of the pump, whereby when adjusted to complete the flow line from the pump to the connecting line between the cylinders, hydraulic fluid will be pumped into the connecting line instead of being drained therefrom. Being that the pressure built up thereby in the lower portion of the master cylinder will be slightly higher than that of the fluid reaching the upper side of this cylinder, due to the slight pressure drop across the check valve 169, and with the greater piston surface exposed to the higher pressure, the associated piston will rise to lift that end of the ram, to thereby decrease the prevailing rake angle.

Withthe main valve assembly in neutral position, which renders the machine idle, the piston associated with the slave piston assembly, will effectively be locked, regardless of which of the rake angle control valves may be in use, so that in either case the ram will pivot about the slave piston assembly when making rake angle adjustments under these conditions.

With the main valve assembly being shifted between one end section and the other which would normally poduce reciprocation of the ram, it can be shown that the rake angle control valves will still function to effect adjustments of the rake angle. For example, with the main valve assembly adjasted for a down stroke, draining of fluid from the interconnecting line to tank will cause the master piston to descend and lower its end of the ram, while the fluid emerging from the lower end of the master cylinder will by-pass the slave cylinder, thus increasing the rake angle.

Likewise, when the main valve assembly is shifted to the position which would normally restore the ram to its uppermost position in its cycle of operation, draining of fluid from the interconnecting line to tank will cause fluid to by-pass the master cylinder, thus continuing the increase in rake angle. Thus regardless of the adjustment of the main valve assembly, the operation of rake angle control valve assembly 211 to drain fluid from the interconnecting line, will bring about an increase in rake angle.

Again considering the main valve assembly shifted for a down stroke, and with the other rake angle control valve assembly 213 adjusted to close its flow line between the interconnecting line and the power side of the pump, fluid under pressure will enter both cylinders in parallel, with the fluid to the lower end of the master cylinder being slightly higher in pressure than that in the upper end of that cylinder, by the drop across of the check valve, while the pressure of the fluid to the upper end of the slave cylinder will exceed that in the lower end, which will be at atmosphere pressure. Thus both pistons will cooperate in rotating the ram in the direction of reducing the rake angle thereof.

During the up stroke adjustment of the main valve assembly, full pressure will continue to be applied to the lower side of the master piston and the upper side of the slave piston, and over a greater surface of the master piston than the fluid pressure applied to the upper side of this piston. Fluid pressure applied to the upper side of the master piston and lower side of the slave piston will be slightly lower by the drop across the check valve 169. Taking into consideration the difference in areas between the lower and upper sides of each piston, it follOWs that, under the conditions noted, the master piston will move upward at a faster rate than the slave piston, thus decreasing the rake angle of the ram.

It will be noted therefore that, while the system described permits of rake angle adjustment while the machine is not operating, that is with the main valve assembly in its central or neutral position, rake angle adjustments can also be realized even while the main valve assembly may be in any of its other adjustable positions.

Inasmuch as a stroke of the ram in a shear or like machine is qu-ite short, for example, less than an inch for light duty machines, depending on the thickness of material to be sheared, observable means may be mounted on the ram proper to indicate rake angle control adjustments while they are being effected. A pendulum supported on the ram, for example, and operating in conjunction with a scale on the ram, may provide one means for accomplishing such visual indication, while a bubble glass, such as employed in a level, may constitute an additional means to provide such a visual indication. Or an electrical control circuit may be tied in with such registering devices to automatically control the rake angle control valve assembly when a particular rake angle adjustment has been reached.

By-passing both the hydraulic drive system and the rake angle control system is a relief valve assembly 225 adapted to connect the pump output back to the tank when the pump pressure exceeds a maximum safe value.

The operation of this relief valve assembly is tied to a relief pilot valve assembly 227 which is coupled thereto and during non-operating periods of the machine, normally shorts out the relief valve assembly hydraulically.

Timed to function in cooperation with the down stroke of the ram, is the tube hold-down means 121 previously described. This hold-down tube is a closed ended tube having an air intake coupling at one end for connecting the same to a two section solenoid operated valve assembly 231, one section being adapted to connect a supply of air under pressure to said tube, to produce inflation thereof, while the remaining section of the valve assembly is alapted to provide for instant release of air from such tube. This valve assembly, like those previously described, is preferably solenoid operated.

When the machine and its various valve control systems are electrically controlled, 2. control relay 235, the up solenoid 185, the solenoid 239 of the pilot relief valve assembly 227, the down solenoid 183, and the solenoid 241 of the air control valve assembly for the hold-down tube 121, are each connected at one end to one side of a single phase power supply source 245. The control relay and up solenoid windings are energizable through two pairs of normally closed contacts 251, 253 associated with back

travel limit switches

255, 257 respectively, the contacts being in series with the normally closed contacts 259 of a three position foot switch 261, having two pairs of normally

open contacts

263 and 265, representing intermediate and extreme positions respectively.

The back

travel limit switches

255, 257 are each mounted above a different end of the ram, where at least one pair is in position to be engaged by such ram and opened, when the ram reaches the upper limit of its return stroke. The opening of either pair of normally closed contacts 251, 253, will open the circuit to the control relay and up solenoid with the foot switch in its normally closed position.

Associated with the winding of the control relay are a pair of normally open contacts 269 and a pair of normally closed contacts 271. The normally open contacts are adapted, when closed, to parallel the winding 239 of the pilot relief valve assembly with the up solenoid and control relay 235 while the normally closed contacts 271 place the pilot valve solenoid in parallel with the down solenoid winding 183, which in turn is connected through two pairs of normally closed

contacts

275, 277 associated with down limit switches 281, 283, in series with the normally open lower contacts 265 of the foot switch to the other side of the power supply source. Also conncctable through these normally open contacts of the foot switch, is the solenoid 241 of the air control valve assembly 231.

The two pairs of down

limit switch contacts

275, 277, are each located adjacent a different lower corner of the ram where at least one pair will be engaged by the proximate corner of such ram when it reaches the lower end of its stroke, to open that pair of contacts so engaged.

It will be apparent that with the ram in its uppermost rest position, at least one pair of the normally closed contactsassociated with the back travel limits will be in open condition, depending on the prevailing rake angle of the ram. Accordingly, when power is applied, nothing will become energized.

When the foot switch is depressed to close the lowermost pair of contacts 265 associated therewith, solenoid 241 of the air control valve assembly 231, associated with the hold-down means, will be energized, and simultaneously therewith, the down solenoid 183. Though both will be energized simultaneously, the hold-down tube will inflate practically instantaneously and before the ram can execute a down stroke to shear any work. As the ram approaches the lower limit of its down stroke, it will engage at least one

pair

275 or 277, of the down limit switch contacts, depending on the rake angle adjustment of the ram, and open the circuit to the down solenoid 183, thus removing hydraulic pressure from the ram by causing the main valve assembly to restore itself to neutral.

Upon release of the foot pressure switch, so as to restore the normally open contacts 265 to open condition, the air control valve solenoid 241 will become de-energized and the valve assembly will shift to air release position to remove hold-down pressure from the work and thus release the work.

In the meantime, the downward stroke of the ram has permitted the normally closed contacts of the back travel limit switches to assume their closed condition. Therefore, as the foot switch is permitted to return to its normally closed contacts 261, it will close a circuit through the control relay and the up solenoid, the up solenoid causing the ram to initiate a return stroke and the control relay to energize its contacts, thereby shifting the pilot relief valve solenoid from a parallel connection with the down solenoid to a parallel connection with the up solenoid. Thus the pilot relief valve solenoid will continue to be energized during the operation of the machine, which means that it will block discharge through its associated valve and permit the pump to build up pressure across the relief valve assembly 225 for operation of the machine, whereas during non-operating periods of the machine, the pump will normally discharge through the pilot relief valve assembly back to tank, which in effect means that the pump is idling.

Undesired deviations from a preset rake angle of the ram may be avoided through reliance on a control system, similar to that illustrated and described in Patent No. 2,906,096 to Rolland A. Richardson for Precision Control System for Press Brakes or the like wherein the control system in question was employed as a leveling means for the ram in a press brake type machine.

In the machine as thus described, the recessed upper front edges of the side housings provide room for long pieces of work in much the same manner as the conventional throat. If it is found necessary to utilize this space for work requirements, the piston rods 99 may be formed to include a loop in the direction of the recessed cage. This can be tolerated in view of the shortness of the stroke in a machine of this type.

From the foregoing description of our invention, it becomes apparent the same satisfies all the objects of our invention and while we have illustrated and described the same in its preferred form and in considerable detail, it becomes apparent that the same is subject to alteration and modification without departing from the underlying principles involved, and I accordingly do not desire to be limited in my protection to the specific details illustrated and described, except as may be necessitated by the appended claims.

I claim:

1. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said ram assembly including a ram having rearward extensions terminating in substantially vertical bearing surfaces, with said ram disposed at an angle to said surfaces and in a plane substantially intersecting the line of cut during shearing,

means carried by said side housings for bearing engagement with said substantially vertical bearing surfaces,

means for applying a rearward horizontal component of force tosaid ram assembly to normally hold said ram assembly in sliding engagement with said hearing engagement means,

and means for applying a vertical component of force to said ram assembly of sufiicient magnitude to produce shearing, and a simultaneous forward horizontal component of force in response to the spreading forces developed between blades during shearing.

2. A shear machine comprising a pair of said housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

means carried by said side housings for hearing engagement with said substantially vertical bearing surfaces, said means including a pair of vertically spaced roller brackets mounted on each side housing, and a bearing roller rotatably carried by each of said brackets for contact with said bearing surfaces,

means for applying a rearward horizontal component of force to said ram assembly to normally hold said ram assembly in sliding engagement with said bear ing engagement means,

and means for applying a vertical component of force to said ram assembly of sufiicient magnitude to produce shearing, and a simultaneous forward horizontal component of force in response to the spreading forces developed between blades during shearing, said means including a piston drive assembly adjacent each side housing and operating in substantially the plane of said ram, with one end pivotably anchored to said ram and the other end pivotally anchored to a fixed location on said machine in substantially the plane of said ram.

3. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

means carried by said side housings for bearing engagement with said substantially vertical bearing surfaces, said means including a pair of vertically spaced roller brackets mounted on each side housing, and a bearing roller rotatably carried by each of said brackets for contact with said bearing surfaces,

means for applying a rearward horizontal component of force to said ram assembly to normally hold said ram assembly in sliding engagement with said rollers, said means including a spring adjacent each side housing and anchored under stress between said ram assembly and a point on its associated side housing,

means for applying a vertical component of force to said ram assembly of sufiicient magnitude to produce shearing, and a simultaneous forward horizontal component of force of a magnitude approaching the spreading forces developed between blades during shearing, said means including a piston drive assembly adjacent each side housing and operating in substantially the plane of said ram, with one end pivotably anchored to said ram and the other end pivotally anchored to a fixed location on said machine in substantially the plane of said ram,

and means for changing the rake angle of said upper blade.

4. A shear machine comprising a pair of side housings,

work support spanning said side housings,

means for supporting a lower blade adjacent the rear means carried by said side housings for bearing engagement with said substantially vertical bearing surfaces, said means including a pair of vertically spaced roller brackets mounted on each side housing, and a bearing roller rotatably carried by each of said brackets for contact with said bearing surfaces,

means for applying a vertical component of force to said ram assembly of sufficient magnitude to produce shearing, and a simultaneous forward horizontal component of force of a magnitude approaching the spreading forces developed between blades during shearing, said means including a piston drive assembly adjacent each side housing and operating in substantially the plane of said ram, with one end pivotably anchored to said ram and the other end pivctally anchored to a fixed location on said machine in substantially the plane of said ram, that one of said piston drive assemblies at the higher end of said upper blade, being slightly offset forward with respect to said other piston drive assembly,

and means preventing lateral shift of said ram during shearing.

A shear machine comprising pair of side housings,

a work support spanning said side housings, means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said ram assembly including a ram having substantially vertical bearing surfaces, with said ram disposed at an angle to said surfaces and in a plane substantially intersecting the line of cut during shearing,

means carried by said side housings for bearing engagement with said substantially vertical bearing surfaces, said means including a roller bracket mounted on each side housing, and a bearing roller rotatably carried by each of said brackets for contact with said bearing surfaces,

means for applying a rearward horizontal component of force to said ram assembly to normally hold said ram assembly in sliding engagement with said rollers,

means for adjusting clearance between such blades, said means including an eccentric shaft through each of the said rollers, and means for angularly adjusting the shaft through each of said rollers,

and means for applying a vertical component of force pivotably anchored to said ram and the other end pivotally anchored to a fixed location on said machine in substantially the plane of said ram.

6. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said ram assembly including a ram having rearward extension terminating in substantially vertical bearing surfaces, with said ram disposed at an angle to said surfaces and in a plane substantially intersecting the line of cut during shearing,

means for adjusting clearance between such blades, said means including an eccentric shaft through each each of the lower rollers of each pair, and means for angularly adjusting the shaft through each of said lower rollers,

and means for applying a vertical component of force to said ram assembly of suificient magnitude to produce shearing, and a simultaneous forward horizontal component of force of a magnitude approaching the spreading forces developed between said blades during shearing, said means including a piston drive assembly adjacent each side housing and operating in substantially the plane of said ram, with one end pivotably anchored to said ram and the other end pivotably anchored to a fixed location on said machine in substantially the plane of said ram.

7. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said ram assembly including a ram having rearward extensions terminating in substantially vertical bearing surfaces, with said ram disposed at an angle to said surfaces and in a plane substantially intersecting the line of cut during shearr means carried by said side housings for bearing engagement with said substantially vertical bearing surfaces,

means for applying a rearward horizontal component of force to said ram assembly to normally hold said ram assembly in sliding engagement with bearing engagement means,

and means for applying a vertical component of force to said ram assembly of sufficient magnitude to produce shearing, and a simultaneous forward horizontal component of force of a magnitude approaching the spreading forces developed between such blades during shearing, said means including a piston drive assembly adjacent each side housing and operating in substantially the plane of said ram, each of said piston drive assemblies comprising a pivotal anchor assembly at each end of said ram, a pivotal anchor assembly at a fixed location on said machine at each end thereof and in substantial alignment with one of the other pivotal anchor assemblies, a drive cylinder between aligned pivotal anchor assemblies at each end of said machine, a piston in each said drive cylinder having a piston rod extending through one end of said drive cylinder means connecting said piston rod to one of said pivotal anchor assemblies and means connecting said drive cylinder to the other of said aligned pivotal anchor assemblies,

and means for feeding liquid to either side of each drive piston to vertically reciprocate said ram and simultaneously impart a forward horizontal component of force thereto on the down stroke.

8. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said ram assembly including a ram having rearward extensions terminating in substantially vertical bearing surfaces, with said ram disposed at an angle to said surfaces and in a plane substantially intersecting the line of cut during shearmeans carried by said side housings for bearing engagement with said substantially vertical bearingsurfaces,

and means for applying a vertical component of force to said ram assembly of suificient magnitude to produce shearing, and a simultaneous forward horizontal component of force of a magnitude approaching the spreading forces developed between such blades during shearing, said means including a piston drive assembly adjacent each side housing and operating in substantially the plane of said ram, each of said piston drive assemblies comprising a pivotal anchor assembly at each end of said ram, a similar pivotal anchor assembly at a fixed location on said machine at each end thereof and in substantial alignment with one of the other pivotal anchor assemblies, a drive cylinder between aligned pivotal anchor assemblies at each end of said machine, a piston in each said drive cylinder having a piston rod extending through one end of said drive cylinder and connected to one of said pivotal anchor assemblies, and a fixed rod extending from said drive cylinder at its opposite end and connected to the other'of said pivotal anchor assemblies,

and means for feeding liquid to either side of each drive piston to vertically reciprocate said ram and simultaneously impart aforward horizontal component of force thereto on the down stroke.

9. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

- a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said rarn assembly including a ram having rearward extensions terminating in substantially vertical bearing surfaces, with said ram disposed at an angle to said surfaces and in a plane substantially intersecting the line of cut during shearmeans carried by said side housings for hearing engagement with said substantially vertical bearing surfaces,

' means for applying a rearward horizontal component the spreading forces developed between such blades during shearing, said means including a piston drive assembly adjacent each side housing and operating in substantially the plane of said ram, each of said piston drive assemblies comprising a pivotal anchor assembly at an end of said ram including a mounting tube affixed to said ram with its axis in substantially the plane of said ram, a pressure ring at each end of said mounting tube and having a convex spherical surface, a pressure disc adjacent each of said pressure rings and having a concave surface complementary to the convex surface of its associated pressure ring, a'similar pivotal anchor assembly at a fixed location on said machine, at each end thereof and in substantial alignment with the pivotal anchor assembly above, a drive cylinder between aligned pivotal anchor assemblies at each end of said machine, a piston in each said cylinder having a piston rod extending through one end of said drive cylinder and one of said pivotal anchor assemblies and affixed to said pivotal anchor assembly, and a fixed rod connected to said drive cylinder at its opposite end and similarly alfixed to the other of said pivotal anchor assemblies,

10. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said ram assembly including a ram having substantially vertical bearing surfaces,

means for adjusting clearance between such blades, said means including eccentric shaft means through said rollers, and means for angularly adjusting said eccentric shaft means,

and means for reciprocally driving said ram assembly.

11. A shear machine comprising a pair of side housings,

a Work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said rarn assembly including a ram having rear substantially vertical bearing surfaces,

means carried by said side housings for hearing engagement with said substantially vertical bearing surfaces, said means including a roller bracket mounted on each side housing, and a bearing roller rotatably carried by each of said brackets for contact with said bearing surfaces,

means for adjusting clearance between such blades, said means including an eccentric shaft through each of said rollers, and means for angularly adjusting the shaft through each of said rollers, said means including a crank handle on said shaft and index means on the proximate side housing in association with said handle,

means for reciprocally driving said ram,

and means for preventing lateral shift of said ram during shearing.

12. A shear machine comp-rising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

a ram assembly for carrying an upper blade at a rake angle for cooperation with such lower blade in the shearing of material, said ram assembly including a ram having rear substantially vertical bearing surfaces,

means for adjusting clearance between such blades, said means including an eccentric shaft through each of said rollers, and means for angularly adjusting the shaft through each of said rollers, said means including a crank handle on said shaft and an index plate afiixed to the proximate side housing in asso-- ciation with said handle,

and means for reciprocally driving said ram,

and means for preventing lateral shift of said ram during shearing, said means including a roller bracket carried by said ram assembly adjacent each end thereof, and a bearing roller rotatably carried by said bracket in contact with the proximate side housing.

13. A shear machine comprising a pair of side housings,

a work support spanning said side housings,

means for supporting a lower blade adjacent the rear edge of said work support,

means for adjusting clearance between such blades, said means including an eccentric shaft through each of the lower rollers of each pair, and means for angularly adjusting the shaft through each of said lower rollers, said means including a crank handle of said shaft and an index plate afiixed to the proximate side housing in association with said handle,

means for reciprocally driving said ram,

means for preventing lateral shift of said ram during shearing,

and means for changing the rake angle of said upper blade.

14. A machine comprising a pair of side housings,

a ram assembly extending from one side housing to the other,

a pair of drive piston assemblies, each pivotally anchored to a low frontal location in said machine and having means for drive connection to said ram assembly, said drive piston assemblies lying in a plane at a rearwardly directed angle, whereby a work load will be transmitted through said drive assemblies directly to the frontal base portion of said machine, and any forces which might normally be transmitted horizontally in the rearward direction during operation on Work, will be minimized by a forward horizontal component of force developed by said drive assemblies and attributable to said angular position thereof.

15. A machine comprising a pair of side housings,

a ram assembly extending from one side housing to the other, and including a ram lying in a rearwardly tilted plane,

a pair of drive piston assemblies, each pivotally anchored to a low frontal location in said machine in proximity to one of said side housings and having means for drive connection to said ram assembly, said drive piston assemblies lying in substantially the plane of said ram, whereby said ram will be substantially free of distortion stresses, and a work load will be transmitted through said drive assemblies directly to the frontal base portion of said machine, and any forces which might normally be transmitted horizontally in the rearward direction during operation on work, will be minimized by a forward horizontal component of force developed by said drive assemblies and attributable to said angular position thereof.

16. A machine of the type employing a ram and a tool affixed thereto for performing operation on work, said machine comprising a ram assembly including a ram,

piston drive means supporting said ram assembly for reciprocal movement,

a plurality of rollers mounted behind said ram assembly for rolling engagement therewith during reciprocal movement of said ram assembly, said rollers constituting the main back support for said ram assembly and permitting freedom in the changing of the rake angle of said ram, and said ram assembly having no obstruction to angular adjustment thereof,

means for maintaining said ram assembly in engagement with said rollers,

means for reducing rearward components of load forces generated during operation on a load to minimize load on said rollers,

and means for altering the rake angle of said ram assembly.

17. A ram assembly for a shear machine or the like comprising a ram,

a pair of rearward extensions from said ram terminating in bearing surfaces making an angle with said ram,

said ram having means for afiixing a tool for operation in a plane substantially parallel to the plane of said bearing surfaces.

18. A ram assembly for a shear machine or the like comprising a ram,

a pair of rearward extensions from said ram and including slideways terminating in bearing surfaces making an angle of the order of 13 degrees with said ram,

said ram having means for affixing a tool for operation in a plane substantially parallel to the plane of said bearing surfaces.

(References 011 f0llowing page) References Cited UNITED STATES PATENTS FOREIGN PATENTS 459,241 4/ 1928 Germany. Watkins et 1 3 5 2 X 467,952 6/1937 Great Britain. Jones 83639 X Hazelton a a1. 83 635 5 JAMES M. MEISTER, Primary Examiner. VanZO 83-461 ANDREW R. JUHASZ, WILLIAM W. DYER, IR., Giordano 83635 X Examiners.

Claims

1. A SHEAR MACHINE COMPRISING A PAIR OF SIDE HOUSINGS, A WORK SUPPORT SPANNING SAID SIDE HOUSINGS, MEANS FOR SUPPORTING A LOWER BLADE ADJACENT THE REAR EDGE OF SAID WORK SUPPORT, A RAM ASSEMBLY FOR CARRYING AN UPPER BLADE AT A RAKE ANGLE FOR COOPERATION WITH SUCH LOWER BLADE IN THE SHEARING OF MATERIAL, SAID RAM ASSEMBLY INCLUDING A RAM HAVING REARWARD EXTENSIONS TERMINATING IN SUBSTANTIALLY VERTICAL BEARING SURFACES, WITH SAID RAM DISPOSED AT AN ANGLE TO SAID SURFACES AND IN A PLANE SUBSTANTIALLY INTERSECTING THE LINE OF CUT DURING SHEARING, MEANS CARRIED BY SAID SIDE HOUSINGS FOR BEARING ENGAGEMENT WITH SAID SUBSTANTIALLY VERTICAL BEARING SURFACES, MEANS FOR APPLYING A REARWARD HORIZONTAL COMPONENT OF FORCE TO SAID RAM ASSEMBLY TO NORMALLY HOLD SAID RAM ASSEMBLY IN SLIDING ENGAGEMENT WITH SAID BEARING ENGAGEMENT MEANS, AND MEANS FOR APPLYING A VERTICAL COMPONENT OF FORCE TO SAID RAM ASSEMBLY OF SUFFICIENT MAGNITUDE TO PRODUCE SHEARING, AND A SIMULTANEOUS FORWARD HORIZONTAL COMPONENT OF FORCE IN RESPONSE TO THE SPREADING FORCES DEVELOPED BETWEEN BLADES DURING SHEARING.