US2141951A - Air compressor attachment and brake for forging machines - Google Patents

Description

Dec. 27,1938. w w 2,141951 AIR COMPRESSOR ATTACHMENT AND BRAKE FOR FORGING MACHINES Filed July 16, 1936 5 Sheets-sheaf, l

- INVENTOR. Mal/1M W am ATTORNEY.

Dec. 27-, 1938. v w, w. cRlLEY 2,141,951

AIR COMPRESSOR ATTACHMENT AND BRAKE FOR FORGING MACHINES Filed July 16, 1936 5 Sheets-Sheet 2 lg 3 INVENTOR.

W/Lz /A/1 W CR/Lf):

, r 1 f if ATTORNEY.

-w. w. CRILEY 2,141,951

AIR COMPRESSOR ATTACHMENT AND BRAKE FOR FORGING MACHINES Dec. 27, 1938.

Filed July 16, 1936 5 Sheets-Sheet 3 EV UWO Y B v mm Dec. 27, 1938. w. R Y 2,141,951

AIR COMPRESSOR ATTACHMENT AND'BRAKE FOR FORGING MACHINES Filed July 16, 1956 5 Sheets-Sheet 4 ATTORNEY.

Dec. 27, 1938. w.'w. CRILEY AIR COMPRESSOR ATTACHMENT AND BRAKE FOR FORGING MACHINES Filed-July 16, 1936 5 Sheets-Sheet 5 fig. 6

- INVENTOR. W/LL/AM W 67min Xi ATTORNEY.

Patented Dec. 27, 1938 UNITED STATES PATENT oFFIcE AIR COlVIPRESSOR ATTACHMENT AND BRAKE FOR FORGING MACHINES 4 Claims.

This invention relates to improvements in forging machines and the like of the intermittent drive and brake stop type, and particularly to means for reducing the stresses and wear ordinarily occasioned on the brake in stopping the heavy moving parts, and the effective utilization of kinetic energy of the moving parts which has heretofore not only been wasted but has contributed to wear of parts of the machine.

In machines of this character, the die carrying ram or slide is customarily driven by a crank shaft which, in turn, is driven by large and heavy intermittently operated rotary driving mechanism. The rotary mechanism, in turn, is driven by a continuously rotating flywheel or inertia member to which it is connected or disconnected intermittently by a suitable clutch.

After the ram is driven by this mechanism for effecting the work stroke, the fly wheel and mechanism are then declutched and it becomes necessary to arrest movement of all these heavy working parts when the ram has been returned to its starting position. This has heretofore been accomplished by brake mechanism usually operatively connected to the intermittently operated rotary driving mechanism of the machine.

In machines of this character, all of the moving parts and mechanism are extremely heavy, with the result that when the static inertia thereof is overcome and they are in motion, considerable kinetic energy is present therein.

The brake is necessarily subjected to severe stresses and wear in absorbing the kinetic energy of the moving parts of the machine, and, consequently, not only is wasted but also has detrimental effects.

Again, in prior machines of this character, air compressors have been used for providing pneumatic pressure for operating the brake and clutch mechanism, these compressors being driven directly from the same source of power as the rotating mechanism itself, thus requiring power in addition to that required by the machine.

One of the principal objects of the present invention is to reduce the stresses and wear on the brake and other working parts occasioned by this kinetic energy, and, at the same time, effectively I to utilize the kinetic energy which has heretofore been Wasted and to convert this energy into useful work.

Furthermore, in machines of this character, the gears of the intermittent rotary mechanism are subjected to backlast due to the same kinetic energy of the parts when the brake is applied, and a more specific object is to reduce or eliminate this backlash by converting the energy into useful Work rather than in dissipating the energy as useless heat or detrimental wear.

Another object is to convert the kinetic energy of the moving parts into useful fluid pressure and 5 to utiliz this fluid pressure as the source of power for operating the clutching and braking mechanism, respectively.

Another object of the present invention is to yieldably resist the return of the ram to starting position by fluid pressure until the instant before the ram reaches starting position and thereupon release the fluid pressure as the ram moves into starting position.

It is understood that at the initial installation, or after a long disuse, such machines need compressed air to operate the clutch for starting. However, any low pressure air from a shop line or from a portable tank may be used for this purpose. After a few strokes of the operation of the forging machine or the like, equipped with my invention, sufficient air pressure will be built up in its own system for continued operation.

Further objects will become apparent from the following description which relates to the accompanying drawings.

In the drawings,

Fig. 1 shows an end elevation of a large horizontal forging machine with the present invention attached thereto.

Fig. 2 is a plan view of the machine shown in Fig. 1.

Fig. 3 is an enlarged, fragmentary, vertical, sectional view taken on a plane indicated by the line 3--3 of Fig 1.

Fig. 4 is a sectional view taken along the line indicated at 4-4 of Fig. 3.

Fig. 5 is an elevation of a vertical press or forging machine with the pneumatic counterbalance and compressor attached thereto.

Figs. 6 and '7 are fragmentary sectional views through the compressor unit of Fig. 5, showing different positions occupied by the piston and other operating parts.

Fig. 8 is an elevation of the compressor mounted on the machine shown in Fig. 5.

Fig. 9 is a top plan of the compressor of Fig. 8.

Referring to Figs. 1 and 2, a horizontal forging machine is shown as having a frame indicated at I, carrying a fly wheel 3 adapted to be intermittently and drivingly connected with a countershaft 8 by means of a pneumatically operated clutch designated 6. On the shaft 8 is a driving pinion 9 meshing with a gear II] which is rigid with the main crank shaft l2, and which in line with the header slide.

in turn imparts reciprocating motion, as through a connecting rod Hi, to the header slide or ram l5 carrying suitable forming dies indicated at H.

The compressor unit is shown comprising a cylinder 20 which is mounted on the frame I as by means of bolts and preferably in a position The cylinder may be open at the inner end and closed at the other end by a head 22, shown as secured to ,the cylinder by means of bolts 23.

Fitted in the cylinder is a piston carrying a suitable expanding packing skirt 2B which serves to prevent the air passing the piston during the compression stroke. The piston is shown operatively connected to the header slide by a connecting rod 28 preferably adjustably attached to a forked member 30 embracing the ends of a bearing pin 3| extending through bosses 32 on the header slide l5. The connecting rod 28 and the fork 351 preferably lie in a horizontal plane which is substantially parallel .to the line of motion of the header slide I 5.

The intermittently driven rotating and reciprocating parts of the machine include the countershaft 8, pinion 9, main gear l0, crank shaft l 2, connecting rod !9 and the header slide or ram i5. These parts, when in motion, produce a considerable amount of kinetic energy, especially the main gear Hi.

In machines prior to my invention, the inertia or kinetic energy of these parts was dissipated by a brake mechanism which was applied during the return stroke of the header slide to stop these parts when the header slide 15 reached a predetermined position. As stated above, in such instances, the energy of these intermittently operated rotating and reciprocating parts is dissipated in detrimental wear, heat and shock.

By the use of the present invention, however, some of the stress and wear on the brake mechanism is relieved by absorbing a portion of the kinetic energy of the moving, intermittently operated parts through a pneumatic compressor which transforms this portion of the kinetic energy into compressed air for use in operating the clutch and brake of the forging machine or any other pneumatic device.

During the working stroke of the header slide [5 and dies, the piston 25 is moved toward the open end of the cylinder 20 and draws a charge of air into the cylinder through an intake check valve, indicated at 35. On the return stroke, the intake check valve is closed and the air forced through an exhaust port and a discharge check valve 36 into an air line 38 which leads to an air storage tank 48.

From the storage tank, the air is conducted through an air line 4| and a pressure regulating valve 42 for maintaining a uniform pressure in an operating reservoir 43. Suitable pressure gauges 44 and 45 are provided for gauging the pressure in the tank 40 and reservoir 43, respectively.

The compressor may be designed to maintain any desired pressure of air in the storage tank, for example, 150 pounds per square inch. This is preferably accomplished by providing a predetermined clearance volume between the cylinder head 2?. and the piston 25. Ordinarily, when the piston reaches the end ofthe compression stroke, the air in the cylinder is delivered through the valve 36 to the reservoir 40. When, however, the pressure in the reservoir becomes increased to a predetermined amount, the maximum pressure developed in the cylinder 20 is substantially nate the back lash in the gears.

balance functions to resist the motion of the slide balanced by the pressure on the opposite side of the discharge check valve 36. On the next working stroke when the piston 25 would normally draw a charge of air into the cylinder through the intake check valve, the compressed air in the clearance volume is allowed to expand to atmospheric pressure. Thus, no more air is taken into or ejected from the cylinder, so long as the air in the reservoir 40 remains at proper pressure, which precludes the necessity of a safety valve in the system.

In Fig. 5, a forging machine or press having vertically reciprocating parts is shown in conjunction with a pneumatic counterbalancing and air compressing means associated with the reciprocating parts which is designed to prevent back lash in the driving gears. Such machines have heretofore been provided with substantially constant pressure pneumatic counterbalancing de vices adapted to act in both directions of motion of the reciprocating parts. These prior devices include a cylinder and piston arrangement associated with a substantially constant pneumatic pressure acting on one face of the piston from a surge tank or other air pressure source and urging the slide upwardly only. In such machines there exists considerable back lash between the teeth of the gears during the operating cycle as there is no pneumatic opposition to the rotating and reciprocating parts as the slide moves upwardly, and consequently the teeth of the driven gear are not held in pressure engagement with the teeth of the driving gear as the slide is brought to rest.

By providing a head or cover with an air intake port over the open end of such a pneumatic counterbalancing device so that the piston compresses air on the up-stroke of the slide, I elimi- The counterin the down direction and the compressor acts to resist the upward movement of the slide. Thus the teeth of the gears are held in pressure engagement during the entire operating cycle.

A frame for such a machine is indicated at 59 and is shown carrying a composite fly wheel driving member 52, and a pneumatically operated clutch assembly 54 mounted for rotation on one end of a countershaft 55. A pinion 51 rigid with the countershaft 55 engages a gear 59 mounted on a crank shaft 60. Embracing the eccentric portion of the crank shaft isa connecting rod which is secured to a heavy slide member 65. As the crank shaft revolves, vertical reciprocating motion is imparted to the slide.

As above indicated, in machines having heavy vertical reciprocating members, provision is usually made for counterbalancing the weight of these members. I have shown such a mechanism including a forked member 10, suitably pinned as at H to one end of the slide 65, and adjustably secured at the other end to a piston rod 12 rigidly connected with a piston 13, in a cylinder 14 mounted on the top of the frame 50, as shown in Fig. 5. For counterbalancing, the lower end of the cylinder is connected to a surge tank by means of a conduit 15. This counterbalance mechanism may be readily adapted for the purposes of this invention by providing in the cylinder 14 an intake port 16, and by closing the upper end of the cylinder with a suitable head 11. A poppet valve 18, seated by a light spring 80, admits air to the cylinder 14 as the piston is lowered. A check valve 19 is also connected to the cylinder and discharges through a conduit leading to a storage tank, similar to tank 40 above described, when the air in the cylinder is compressed to a predetermined pressure. Thus, as the piston is raised by the slide 65, air is compressed and delivered to a storage reservoir until the piston has approached closely the end of its stroke.

It will be understood that the pneumatic counterbalance is effective as the piston moves downwardly, which holds the meshing gear teeth in pressure engagement in the work driving direction. On the up-stroke, however, the magnitude of this counterbalancing force gradually decreases, due to the pressure being built up on the upper face of the piston causing resistance to the upward movement of the slide. This resistance holds the gear teeth in pressure engagement and prevents back lash.

In order to insure substantially the same resistance to return movement of the ram on each stroke, the poppet valve 18 is arranged to be opened mechanically by the ram the instant before the ram arrives at its starting position. The means employed for this purpose may comprise a push rod 35, the upper end of which is adapted to engage the free end portion 82 of the poppet valve stem. To move the push rod the head of the forked member 10 has an abutment member in the form of an adjustable stud 86 which is brought against the lower end of the push rod when the forked member on the upward stroke of the ram is moved to the position shown in Fig. '7.

- The pressure-releasing mechanism just described governs a residual pressure in the compressor which otherwise could vary due to leakage with each cycle of operation according to the time interval between successive operations.

From the foregoing description, it will be seen that I have provided a unique combination of a pneumatic counter-balance and air compressor for machines having heavy reciprocating parts and having pneumatically operated controls.

While a limited application of the present invention is disclosed, it may become apparent to those skilled in the art that modifications and other adaptations may be made without departing from the spirit and scope as defined in the hereunto annexed claims.

Having thus described my invention, What I claim is:

1. In a forging machine having a heavy intermittently operated mechanism, said mechanism including a crank shaft, a reciprocating ram connected to the shaft so that the ram is reciprocated thereby in one direction for effecting a forming operation and in the opposite direction to return the ram to starting position, a main gear carried by the crank shaft, a primary rotary member, gear means operatively interposed between said main gear member and the rotary member, a pneumatic means operatively connected to the ram and yieldably opposing movement of the ram on the return stroke, and valve means associated with the pneumatic means and controlled by the ram for releasing pressure in the pneumatic means at the instant before the ram is returned to starting position.

2. In a forging machine of the stop-motion type comprising a power operated, continuously driven, rotary inertia member, a rotary driven mechanism including a train of gears, a clutch for selectively connecting and disconnecting the rotary driven mechanism at one end of the train to and from the inertia member, respectively, a reciprocable ram slide, a crank at the other end of said train operatively connecting the rotary driven mechanism to the ram slide for positively driving the ram slide on a work stroke and a return stroke consequent upon rotation of the rotary driven mechanism, a brake for reducing the momentum of the rotary driven mechanism when the rotary driven mechanism is disconnected from the inertia member and for stopping the rotary driven mechanism, said brake being applicable to the rotary driven mechanism adjacent said one end of the train, a fluid compressor mechanism connected to the ram slide for operation thereby to compress fluid when the ram slide moves on its return stroke and thereby to resist 'yieldably the return of the ram slide, whereby the momentum of the ram slide and the momentum of the rotary driven mechanism may be concurrently and individually reduced for preventing back lash of the train of gears and for relieving the brake mechanism from absorbing heavy inertia stresses occasioned by the momentum of the ram slide and the rotary driven mechanism.

3. In a forging machine of the stop-motion type comprising a power operated continuously driven rotary inertia member, a rotary driven mechanism including a series of meshing gears, a clutch for selectively connecting and disconnecting the rotary driven mechanism at one end of the series of gears to and from the inertia member respectively, a reciprocable ram slide and crank at the opposite end of the series of gears, said crank connecting the rotary driven mechanism and the ram slide for positively driving the slide on a work stroke and a return stroke consequent upon rotation of the rotary driven mechanism, a brake for reducing the momentum of the rotary driven mechanism when the rotary driven mechanism is disconnected from the inertia member and for stopping the rotary driven mechanism, said brake being applicable to the rotary driven mechanism adjacent said one end of the series of gears, means connected to the ram slide independently of the rotary driven mechanism and operative to yieldably resist return movement of the ram slide, whereby the momentum of the ram slide and the momentum of the rotary driven mechanism may be concurrently and individually reduced for preventing back lash of the series of gears and for relieving the brake mechanism from absorbing heavy inertia stresses occasioned by the momentum of the ram slide and the rotary driven mechanism.

4. In a forging machine of the stop-motion type comprising a power operated continuously driven rotary inertia member, a rotary driven mechanism comprising a rotatable shaft, a clutch for operatively connecting and disconnecting said shaft and the inertia member, a pinion on said shaft, a driven gear meshing with the pinion, a ram slide having a predetermined initial starting position, means connecting the ram slide and the driven gear for positively reciprocating the ram on a work and return stroke consequent upon rotation of said pinion and gear, a compressor mechanism directly connected to the slide independently of the pinion and gear, and operated by the slide to compress air and resist movement of the slide on its return stroke, a brake for applying braking resistance to the shaft for reducing the momentum of and stopping the rotary driven mechanism and shaft as the ram approaches the predetermined initial position on its return stroke.

WILLIAM W. CRILEY.

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