US3306122A - Press - Google Patents

Description

R. F. DEHN Feb. 28, 1967 PRESS 2 Sheets-Sheet 1 Filed April 28, 1964 INVENTOR PoY F DEHN BY 9% ATTORNEYS R. F. DEHN Feb. 28, 1967 PRESS 2 Sheets-Sheet 2 Filed April 28, 1964 vat ww mun .1.

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ATTORNEYS f Gul United States Patent 3,396,122 PRESS Roy F. Dehn, Wiciriiffe, Uhio, assignor to The Cleveland Crane & Engineering #Company, Wicklifie, Ohio, a corporation of fihio Filed Apr. 28, 1964, Ser. No. 363,163 6 Claims. (Cl. 74-364) This invention relates to power-operated apparatus having a work-performing member movable through an operating cycle which includes a relatively slow working portion preceded by a relatively fast approach portion and followed by a relatively fast return portion. More particularly, the invention relates to a flywheel-type press, shear or like metal working apparatus whose movable ram, platen, etc., that is, the movable work-performing member, is moved through a cycle of the character referred to.

The principal object of the invention is the provision or an apparatus of the character referred to wherein the transition from one speed to the other, and more particularly from the rapid approach to the slower working portion of the Operating cycle, is effected smoothly and with a minimum of strain on the operating parts.

Another object of the invention is the provision of an apparatus of the character referred to having a novel and improved two-speed drive for the movable work-performing member of the apparatus, including a first clutch in the high speed drive, and, in the low speed drive, a second clutch and reduction gearing ahead of the second clutch which gearing is arranged to be driven continuously at the same speed, regardless of whether the high speed drive or the low speed drive is engaged. Accordingly, when changing over from high speed to low speed operation or drive during the forward movement of the work performing member, no change is required in the speed at which the reduction gearing is running and the transmission can be made smoothly and efliciently.

The invention resides in certain constructions and combinations and arrangements of parts, and further objects and advantages will be apparent to those skilled in the art to which it relates from the following description of certain presently-preferred embodiments described with reference to the accompanying drawings forming a part of this specification, in which:

FIGURE 1 is a front perspective view of a press of the bending brake type embodying the present invention;

FIGURE 2 is a fragmentary longitudinal sectional view, with portions in elevation, illustrating the drive of the press shown in FIG. 1;

FIGURE 3 is a longitudinal sectional view similar to FIG. 2 but showing an alternative drive; and

FIGURE 4 is a longitudinal sectional view similar to FIG. 2 but showing a further alternative drive.

Referring to FIGURE 1, the press or bending brake shown therein generally comprises a frame having opposite upstanding end plates 11, only one of which appears in this figure, and a front plate or lower leaf member 13 which carries a lower die plate 14. This die plate supports a die 15 which, in the illustrative embodiment shown, has an upwardly facing V-shaped cavity. A complementary upper die 16 is connected to the lower end of an upper leaf member or ram 17, which is slidably supported above the die plate 14 for reciprocation vertically by pitmans 18 and 19, which are pivotally connected to the ram 17 and to the cranks of a crankshaft 20 journalled in the crown or upper end of the frame 10. The crankshaft 20 is driven by two bull gears 21 and 22, attached to its opposite ends. The bull gears are driven from a motor-driven flywheel through a two-speed drive in accordance with the present invention.

Referring to FIGURE 2, the flywheel 23 of the press which flywheel is rotatably supported on a shaft 24 by suitable anti-friction bearings and is driven by an electric motor in the usual manner through a V-belt drive, is adapted to be operatively coupled to the bull gears either through a high speed drive including a first clutch H or through a low speed drive including a second clutch L. The shaft 24 is rotatably supported by bearings in the side frame 11 and a housing or frame member 25 bolted to the left hand side thereof as viewed in the drawings.

The clutch H shown in the high speed drive is of the air-applied, spring-released type and may be of any suitable conventional design, the details of which are not part of the present invention. Desirably, it may be constructed as shown in United States patent to A. W. Schultz No. 2,981,391. The driving clutch structure includes an outer clutch body comprising a cup shaped housing 28, a ring shaped member 38 interposed between the housing 28 and the right side of flywheel 23, and relatively axially displaceable, oppositely disposed, torque transmitting friction clutch discs or members and coupled, that is, keyed to the outer, driving clutch body 28 to rotate therewith. The members 28 and 30 are bolted to the flywheel 30. The driven clutch structure is in the form of an annular, inner, driven clutch body or disc 33, which may be a friction disc, disposed axially between the driving friction members splined or keyed to the driven clutch housing 28. The driven clutch member 33 is splined for axial displacement within the housing 28 on a hub 35 keyed to the shaft 24.

The high speed clutch H is adapted to be engaged by the driven member 33 being clamped and held between the driving discs 31, 32 by pressure exerted against the right hand side of the disc 32 by an annular piston 35 rotatable with and axially displaceable within the outer clutch housing 28. The piston is moved toward the left by air pressure to engage the clutch and is retracted or moved in the opposite direction by a spring 36 when the air pressure is released. In the absence of air pressure on the clutch, the friction members 30, 31 carried by the driving clutch body 28 are disengaged from the driven clutch body 33, so that the driving clutch structure is free to rotatewith respect to the driven clutch structure. When suitable air pressure is applied to the clutch, that is, between the member 28 and the right hand side of the piston 35, the driven clutch body 33 is frictionally engaged by the friction members 31, 32 so that it rotates with the driving clutch body 28 and transmits torque from the latter to the shaft 24. Air is supplied to and released from the clutch through a rotary seal fitting of known design, which is located at the right end of the outer housing 28 of the clutch, i.e., the end of the clutch away from the flywheel 23.

As previously stated, the driven clutch body 33 of clutch H is splined to the hub member 31 fixed to the right end of shaft 24, so that when clutch H is engaged it transmits torque from the flywheel 23 to shaft 24. Shaft 24 carries a pinion 45 keyed thereon which drives a larger gear 46 keyed to a shaft 47 extending across the press. Shaft 47 carries a pinion 48 at one end which drives the bull gear 21. At its opposite end (not shown) shaft 47 carries another similar pinion which drives the other bull gear 22.

With the construction just described, the high speed drive from the flywheel 23 to the bull gears and in turn the crankshaft 20 is by way of the first or high speed clutch H, shaft 24, pinion 45, gear 46, shaft 47, 48 in mesh with bull gear 21, and the corresponding pinion or shaft 47 in mesh with bull gear 22.

The second clutch L in the low speed drive includes an annular, inner, driven clutch body 50 splined to a hub member 51 keyed to the left hand end of shaft 24. This second clutch also includes a driving clutch body in the form of an outer housing 52, which carries axially spaced, opposite friction members 53 and 54 splined to the housing 52 for torque-sustaining, frictional engagement with the driven clutch body 50. This second clutch 25 also is air-applied and spring-released. Air is supplied to, and released from this clutch through a rotary seal fitting 55 of known design, which is located at the left end of the outer housing 52, Le, the end of the clutch away from the press frame end plate 11. The second clutch insofar as it has been described is similar to the first. The difference between the two clutches is that in the case of the clutch L the driving housing 52 is bolted to a flanged member 60 the hub 61 of which surrounds the shaft 24 and is rotatably supported in the end plate 11 by suitable bearings.

In accordance with the provisions of the present invention, reduction gearing is connected between the flywheel 23 and the driving assembly of the second clutch L which assembly includes the members 52 and 60. In FIGURE 2 this reduction gearing includes a pinion 62 surrounding or coaxial with the shaft 24 and attached to the left hand sides of the flywheel 23. The pinion 62 rotatably surrounds shaft 24. This pinion drives a larger gear 63 affixed to a rotatably mounted shaft '64 which shaft in turn carries a pinion 65, in mesh with a larger gear 66 affixed to a reduced diameter hub 61 of the member 60 of the driving clutch assembly of clutch L.

With the construction shown the reduction gearing and the driving clutch structure of the second clutch L is driven at all times from flywheel 23 as is the driving clutch structure of the first clutch H through the reduction gearing 62-66. The driving clutch structure of the clutch L, however, is driven at a reduced speed. As one practical example, in the bending brake shown, the flywheel speed may be 600 revolutions per minute and the speed of the driving assembly of the clutch L in the low speed drive 75 rpm. For draw presses, the speed reduction preferably would be less, for example, 4 to 1 or 3 to 1. Obviously, any desired reduction may be employed.

The reduction gearing 62-66 in the low speed drive is enclosed by the housing 25 and a second member 67 bolted to the right hand side of the member 25. This member and the end plate 11 carries the anti-friction bearings which rotatably support the shaft 64.

The brake drum 70 of a conventional spring-applied air-released band brake is attached to the pinion shaft 47 just to the right of housing 25 as shown in FIG. 2. This brake is applied whenever neither clutch is disenagageable, and it is released whenever either clutch is engaged. In the operation of the press, the two clutches H and L are applied alternatively, that is, when one is engaged, the other is always disengaged.

The ram 17 is normally in its raised position shown in FIG. 1 and during each complete reciprocation is first lowered at high speed through the approach portion of its downward stroke, that is, until the upper die just engages or is about to engage the workpiece. In the final working portion of its downward stroke, the ram is driven at low speed for various well understood reasons, such as, to avoid whipping the workpiece or otherwise endangering the operator of the press. At the termination of the working stroke the ram is returned quickly to its upper or starting position.

The first clutch H is engaged to connect the high speed drive from the flywheel 23 to the bull gears 21, 22 during the approach portion of the rams downward stroke. During the final or working portion of the rams downward stroke the second clutch L is engaged to connect the low speed drive from the flywheel 23 to thebull gears, it being understood, of course, that the first clutch H is disengaged before the second clutch L is engaged. Upon completion of the working stroke the second clutch L is disengaged and the first clutch H reengaged to return the ram to starting position.

A suitable control arrangement, preferably including limit switches operated by the ram, is provided to effect an automatic changeover from the high speed drive to the low speed drive at the proper time in the downward stroke of the ram and effect the rapid return stroke. Controls of this character are well known in the art, for example, the controls shown in United States patents to Roy F. Dehm No. 3,046,874 and No. 3,062,132 may be adapted to the bending brake shown. The reference character 71 designates a pedal switch for initiating operation of the ress.

p A particular advantage of the present invention is that the reduction gearing 62-66 is driven at all times directly by the flywheel 23, that is, these relatively heavy parts in the low speed drive are being driven from the flywheel at the same speed at which they will run when the low speed clutch L is engaged during the downward stroke of the ram. When the drive is shifted from high speed operation to low speed operation, therefore, it is not necessary to change the speed of the reduction gearing in the establishment of the low speed drive. Consequently, the transition from the high speed drive to the low speed drive occurs smoothly and quickly and without the imposition of any unnecessary load on the second clutch L when the latter is brought into engagement.

In contrast, if the positions of the second clutch L and the reduction gearing were reversed, that is, if the second clutch L were connected to the flywheel ahead of the reduction gearing, then, during the operation of the high speed drive there would be a back drive from shaft 24 through the reduction gearing which would drive the reduction gearing at a speed several times the speed at which it operates when the low speed drive is engaged. This would involve the imposition of an unnecessarily heavy starting load upon engagement of the high speed drive and a further significant waste of power as long as the high speed drive remains engaged. The foregoing is particularly so having in mind the fact that in presses of the type here involved the reduction gears, etc., are relatively heavy. A further disadvantage would be the fact that when the low speed drive was brought into engagement the reduction gearing would have to be slowed down to a fraction of its former speed. The present invention completely avoids these disadvantages.

In the construction shown in FIG. 2, the air supply fittings 40 and 55 are connected directly to the respective clutch elements 28 and 52, and there is no necessity for air passages in the drive shaft 24 to supply air to either clutch.

FIGURE 3 shows an alternative speed drive which has essentially the same advantageous characteristics as the embodiment of FIG. 2. In FIGURE 3, the clutches, reduction gearing and many of the other parts or elements are essentially duplicates of parts or elements shown in FIG. 2 and are designated by the same reference numerals as in FIG. 2, with an a subscript added, even though in some instances they may be of slightly different construction.

The high speed drive, in FIG. 3, is from the flywheel 2311 through the outer, driving clutch body 28a and the inner, driven clutch body 33a of the first clutch Ha, bub member 34a, shaft 24a, pinion 45a and gear 460 to the pinion shaft (not shown) which drives the bull gears (not shown). A housing 25a which encloses pinion 45a and gear 46a is bolted to the inside of the left end plate 11 of the press frame. This end plate 11 and the housing 25a. carry anti-friction bearings which rotatably support shaft 24a.

A second shaft is connected end-to-end and coaxially to shaft 24a at the latters right end by a detachable, rigid, split-clamp coupling 81 of known design. The first pinion 62a in the reduction gearing is splined to a rigid, split coupling sleeve 82, which is fastened to the outer, driving clutch body 28a of the first clutch Ha. This pinion 62a rotatably receives shaft 80. The reduced hub 61a on the member 60a of the outer, driving clutch body 520 of the second clutch L also rotatably receives shaft 80 and both the pinion 62a and the member 52a are rotatably supported in a gear case 83 fixed to the crown or some other suitable part of the press frame. The reduction gearing 6241-6511 in the low speed drive is enclosed by the gear case or housing 83.

The low speed drive from the flywheel 23a to the bull gears is by way of the outer, driving clutch body 28a of the first clutch Ha, coupling sleeve 82, pinion 62a, larger gear 63a, shaft 641:, pinion 65a, larger gear 66a, the outer, driving clutch element 52a and the inner, driven clutch element 56a of the second clutch La, hub mern'ber 51a, shaft 84), coupling 81, shaft 24a, pinion 45a and gear 46a, etc.

A brake 86 of known design is mounted 'on the opposite (left) end of shaft 24a. Preferably, this brake is spring-applied and air-released in accordance with known practice and is generally similar in construction to the clutches heretofore described. Brakes of the general construction shown are disclosed in US. Letters Patent to William E. Ward No. 2,759,583 and to Roy F. Dehm No. 2,848,082. The brake is applied whenever neither clutch is engaged, and it is released whenever either clutch is engaged.

The brake and the high speed drive shown in FIGURE 3 may be employed with or without the low speed drive. The low speed drive may be added, if desired, as an accessory to a press in the field having a single drive.

Air is supplied to, and released from, the first clutch Ha through a rotary seal fitting 40a connected to a longitudinal passage 83 in shaft 24a. Passage 83 leads to cross passages 84 communicating through suitable seals with the cylinder of clutch Ha. Air is supplied to, and released from, the second clutch La through a rotary seal fitting 55a.

Air is supplied to and released from the brake 80 by a fitting 86. The controls for operating the clutches and the brake may be the same as those previously referred to.

A third embodiment of the two-speed drive is shown in FIG. 4. This embodiment has essentially the same advantages as the first two embodiments. Corresponding elements of this drive are given the same reference numbers as in FIGS. 2 and 3, with a b subscript added.

The structural arrangement and operation of the high speed and low speed drive elements is substantially identical to the FIG. 2 arrangement and therefore the description of these elements will not be repeated.

The brake 80b in this instance is mounted on a brake shaft 80a, which is rigidly coupled end-to-end and coaxially to shaft 24b by a split-clamp coupling 81b. The right hand end of the shaft 80b is rotatably supported in the right hand end plate 12 of the press frame. Air is supplied to and released from brake 55b through a fitting 86b of known design. This brake preferably is spring-applied and air-released. Desirably, this brake may be constructed as disclosed in the aforesaid United States Letters Patent No. 2,759,583 or 2,848,082. The brake is applied whenever neither clutch is engaged, and it is released whenever either clutch is engaged.

Air is supplied to, and released from, the clutches Hb and Lb through a rotary seal fitting 90. Fitting 90 communicates directly with the second clutch Lb. Fitting 90 also communicates with the first clutch Hb through a longitudinal passage 83b and cross passages 84b in shaft 24b. Both of these clutches are air-applied and spring-released, and they are engaged selectively in the manner heretofore referred to in connection with the embodiment shown in FIG. 2.

Attention is called to the fact that in all of the embodiments shown both the high speed and the low speed clutches drive the same shaft, that is, the shaft which carries the pinion that drives gear 46 or its counterpart 46a, 46b. This is important because in practice the clutch torque, that is, the torque at which it slips is sized 6 or designed to deliver the rated press tonnage at or near midstroke with the result that when the press is overloaded above the bottom center the clutch will slip thus saving the press from damage. Since both clutches are connected to the same shaft, each clutch gives the same protection. With other designs much 'higher torque is available in low speed than in high speed which can cause damage to the press under certain operating conditions.

It can be seen from the foregoing that I have provided a power-operated machine comprising a flywheel and having a two-speed drive with reduction gearing connected ahead of the clutch in the low speed drive, i.e., between the flywheel and that clutch, which reduction gearing is driven at all times by the flywheel so that it is at the proper speed when the transition is made from the high speed drive to the low speed drive. Consequently, this transition can be made quickly and smoothly and without imposing a heavy strain on the clutch in the low speed drive, and waste of power is avoided.

The presently-preferred forms of the invention have been described in detail with reference to the accompanying drawings. It is to be understood, however, that the invention is not limited to the particular arrangements shown, and it is my intention to cover hereby all adaptations, modifications and changes therein which come within the practice of those skilled in the art to which the invention relates and the scope of the appended claims.

Having thus described my invention, what I claim is:

1. In a power-operated apparatus having a motordriven flywheel and a crankshaft, a high speed clutch mounted coaxial with said flywheel at one side thereof and having driving and driven structures operatively connected to the flywheel and to the crankshaft, respectively, speed reduction means operatively connected to the flywheel, a low speed clutch mounted coaxial with said flywheel at the other side thereof and having driving and driven structures operatively connected to said reducing gearing and to said crankshaft, respectively, and means for substantially simultaneously disengaging said high speed clutch and engaging said low speed clutch.

2. A press or the like of the character referred to having a motor-driven flywheel means, a crankshaft, a high speed clutch comprising relatively rotatable driving and driven clutch structures supported coaxial with and located at one side of said flywheel means for selectively bringing said driving and driven clutch structures into torque-sustaining engagement with each other, means for coupling said driving clutch structure to the flywheel means to be driven thereby, means for coupling the driven clutch structure to the crankshaft to drive the latter when the high speed clutch is engaged, a low speed clutch comprising relatively rotatable driving and driven clutch structures supported coaxial with and located at the other side of said flywheel means for bringing said last-mentioned driving and driven clutch structures into torque-sustaining engagement with each other, means for coupling the driven clutch structure of the low speed clutch to the crankshaft, and speed reduction drive means having its input coupled to the flywheel means to be driven thereby and having its output coupled to said driving clutch structure of the low speed clutch.

3. In a power-operated apparatus of the character referred to having a flywheel, a crankshaft, a frame with an upstanding end plate, and a two-speed drive for selectively driving the crankshaft at either of two speeds from the flywheel, said two-speed drive comprising a high speed clutch having relatively rotatable driving and driven clutch structures and means for selectively bringing said driving and driven clutch structures into torquesustaining frictional engagement with each other, said driving clutch structure being attached to one side of the flywheel to rotate therewith, a drive shaft rotatably extending through said flywheel, means coupling said drive shaft to said driven clutch structure of the high speed I clutch for rotation in unison therewith, speed reducing means including an input element attached to the opposite side of the flywheel to rotate therewith and rotatably receiving said drive shaft, said speed reducing means including an output element driven at reduced speed from said input element, a housing surrounding said speed reducing means and attached to the inside of a said end plate of said frame, a low speed clutch at the outside of said end plate having an outer driving clutch structure and an inner driven clutch structure rotatable relative to each other and means for bringing said lastmentioned driving and driven clutch structures into torque-sustaining frictional engagement with each other, said driving clutch structure of the low speed clutch having a reduced hub rotatably supported by said end plate and extending therethrough and carrying said output element of said speed reducing means, means coupling the driven clutch structure of the low speed clutch to said drive shaft to rotate therewith, and drive means coupling said drive shaft to the crankshaft.

4. In a power-operated apparatus as claimed in claim 3, a rotary seal fitting for supplying air to the high speed clutch located in direct proximity to the end of said high speed clutch which is away from the flywheel, and a rotary seal fitting for supplying air to the low speed clutch located in direct proximity to the end of said low speed clutch which is away from said end plate of the frame.

5. In a power-operated apparatus as claimed in claim 3, a rotatable brake shaft, rigid means detachably connecting said brake shaft to said drive shaft in end-to-end, coaxial relation therewith, and a brake on said brake shaft having provision for selectively braking the latter to thereby stop said drive shaft from rotation upon disengagement of said clutches.

6. In a power-operated apparatus having a flywheel,

, a crankshaft, a high speed clutch having relatively rotatable driving and driven clutch structures and means for selectively bringing said driving and driven clutch structures into torque sustaining frictional engagement with each other, said driving clutch structure being attached to the flywheel to rotate therewith, a drive shaft rotatably extending through said flywheel, means coupling said drive shaft to said driven clutch structure for rotation in unison therewith, a second shaft, rigid means detachably connecting said second shaft in end-to-end coaxial relation with said drive shaft, speed reducing means including an input element rotatably receiving said second shaft and including an output element driven at reduced speed from said input element, rigid means detachably connecting said input element to said driving clutch structure of the high speed clutch, and a low speed clutch having relatively rotatable driving and driven clutch structures and means for bringing said last-mentioned driving and driven clutch structures into torque-sustaining engagement with each other when the high speed clutch is released, said driving clutch structure of the low speed clutch being connected to said output element of said speed reducing means to rotate therewith, and said driven clutch structure of the low speed clutch being connected to said second shaft to impart rotation to the latter when the low speed clutch is engaged.

References Cited by the Examiner UNITED STATES PATENTS 2,856,044 10/1958 Koenig et al. 74-364 2,983,348 5/1961 Ott 192-145 2,998,732 9/1961 Nelson 74364 DAVID J. WILLIAMOWSKY, Primary Examiner.

H. S. LAYTON, Assistant Examiner.

Claims (1)

1. IN A POWER-OPERATED APPARATUS HAVING A MOTORDRIVEN FLYWHEEL AND A CRANKSHAFT, A HIGH SPEED CLUTCH MOUNTED COAXIAL WITH SAID FLYWHEEL AT ONE SIDE THEREOF AND HAVING DRIVING AND DRIVEN STRUCTURES OPERATIVELY CONNECTED TO THE FLYWHEEL AND TO THE CRANKSHAFT, RESPECTIVELY, SPEED REDUCTION MEANS OPERATIVELY CONNECTED TO THE FLYWHEEL, A LOW SPEED CLUTCH MOUNTED COAXIAL WITH SAID FLYWHEEL AT THE OTHER SIDE THEREOF AND HAVING DRIVING AND DRIVEN STRUCTURES OPERATIVELY CONNECTED TO SAID REDUCING GEARING AND TO SAID CRANKSHAFT, RESPECTIVELY, AND MEANS FOR SUBSTANTIALLY SIMULTANEOUSLY DISENGAGING SAID HIGH SPEED CLUTCH AND ENGAGING SAID LOW SPEED CLUTCH.

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