US2755687A

US2755687A - Inching assembly for power presses

Info

Publication number: US2755687A
Application number: US318299A
Authority: US
Inventors: James C Danly
Original assignee: Danly Machine Specialties Inc
Current assignee: Danly Machine Specialties Inc
Priority date: 1952-11-01
Filing date: 1952-11-01
Publication date: 1956-07-24
Anticipated expiration: 1973-07-24

Description

ly 24, 1956 J. c. DANLY 2755687 INCHING ASSEMBLY FOR POWER PRESSES Filed Nov. 1, 1952 2 Sheets-Sheet l uvmvrm 54465 C. 04AM r 2, ,6 y 1956 J. c. DANLY 75s 87 INCHING ASSEMBLY FOR POWER PRESSES Filed Nov. 1, 1952 2 Sheets-Sheet 2 INVENTOR. Jimss C. DfiM/L Y United States Patent IN CHING ASSEMBLY FOR POWER PRESSES James C. Danly, River Forest, 11]., assignor to Danly Machine Specialties, Inc., Chicago, 111., a corporation of Illinois Application November 1, 1952, Serial N 0. 318,299

3 Claims. (Cl. 74-665) My invention relates to an inching assembly for power presses and more particularly to an improved means for inching presses independent of the main drive train of the press.

Power presses are normally driven from the energy imparted to a continuously rotating flywheel. Typically, an electric motor drives a large flywheel continuously by means of a plurality of V-belts or the like. The driving train of the press is normally immobilized by a brake. When it is desired to operate the press, the brake is released and the flywheel clutched to the driving train of the press. The work in a power press is accomplished through a small part of the cycle of the press. The motor does not have suificient energy to drive the ram and the die to do the work. This energy comes from that stored in the flywheel of the press.

When dies are to be installed in the press or to be adjusted, the press must be able to be started and stopped in order to move it through small fractions of its cycle in the vicinity of its working position. In the prior art the press is fitted with an inching control whereby the press may be moved through small amplitudes of motion. This is usually accomplished by means of an inch button, which gives sensitive control of the press slide to enable proper adjustments of the dies to be made by moving the ram for a very small period of time. The inching control, however, of all prior art presses operates through frame. In the prior art the brake housings for power the flywheel and the main drive train of the press. If it I is desired to inch in a reverse direction, the main motor must be stopped and actuated in the reverse direction.

This is a time-consuming procedure.

Many presses are designed for a comparatively highspeed operation in order to get increased output. In these presses inching becomes a diflicult problem, especially when very small amplitudes of motion are desired. The high speed of normal operation of the press makes it imperative to inch the press through a very brief period of time if one wants a small motion of slide.

One object of my invention is to provide an improved inching assembly for power presses.

Another object of my invention is to provide an inching assembly in which the press may be inched in either the forward or reverse direction with great accuracy and ease.

Other and further objects of my invention will appear from the following description.

in the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

Figure l is a perspective view of the crown of a power press equipped with an inching assembly of my invention.

Figure 2 is a sectional view taken along the plane 2-2 of Figure l drawn on an enlarged scale.

Figure 3 is a sectional view drawn on a smaller scale taken along the line 3-3 of Figure 2.

In general my invention contemplates the provision of a brake housing which is rotatably mounted in the press presses are rigidly secured to the power press frame. In my invention, the brake housing, however, is provided with means for rotating it when it is desired to inch the press. In the normal operation of the press, the rotatably mounted brake housing is immobilized. By means of my improved construction, when it is desired to inch, the brake is left set and the clutch is left unclutched. The driving train of the press is operated not from the main motor through the flywheel, but from a separate inching motor which is mounted conveniently upon the press frame. The inching motor is provided with a simple control consisting only of a reversing starter adapted to operate the motor in one direction or another by appropriate control buttons (not shown). Though the press operates at a very high speed and the flywheel is rotating at a correspondingly high speed, the main drive motor of the press and its flywheel are not employed in the inching operation. Thus the press can be inched expeditiously, rapidly, accurately and simply.

More particularly referring now to the drawings, the press frame 10 is formed integrally with a brake mounting member 12. The member 12 is adapted rotatably to position a brake housing assembly 14. Formed integrally with or secured to the end of the brake housing assembly 14, i provide a worm wheel 16 adapted to rotate upon a bushing 18 carried by the mounting member 12. A cover plate 20 is secured to the member 12 by means of screws 22 and serves to hold the worm wheel 16 in a position concentric with the shaft 24, which is the driving shaft of the press. The shaft 24 carries at one end thereof a brake disc 26. The brake housing 14 is formed with a stationary brake plate 28. A movable brake plate 30 is normally urged to the left as viewed in Figure 2 by springs 32, thus clamping the friction blocks 34 carried by the brake disc 26 between the stationary brake plate 28 and the movable brake plate 30. The right-hand ends of springs 32 bear against member 41, which is secured to the brake housing assembly 14 in any appropriate manner, such as by bolts 39. In this mannor the brake disc is immobilized to the brake housing 14. A worm 35 is rotatably positioned in the lower portion of the mounting member 12 and has its spiral engaging the teeth of the worm wheel 16. The worm 36 is secured to a shaft 38, as can readily be seen by reference to Figure 3. This shaft is coupled by coupling 40 to a gear transmission housed in gear box 42. The transmission is adapted to be driven by a motor 44. The out put of the transmission is through shaft 46 which is in turn coupled to shaft 38. The pitch angle of the worm 36 is quite small so that a very small braking force upon the motor 44 will immobilize the worm wheel 16. Thus the brake housing is immobilized through the worm wheel and the worm to the mounting member 12, which is in turn integral with the press frame 10. The other end of the drive shaft 24 carries a clutch assembly (not shown). The brake housing is formed with an annular cylinder 47 adapted to coact with an annular piston 48. When a fluid under pressure is passed into the cylinder47, the annular piston 48 will lift the movable brake plate 36 against the action of springs 32 to release the brake. As is well known in the art, this action occurs simultaneously with the setting of the clutch to drive or inch the shaft 24 to be driven from the flywheel of the press (not shown). The rotation of shaft 24 will rotate the pinion 50, which is, as understood by those skilled in the art, in mesh with the driving gear train of the press. Normally the motor 44 is stationary and may, if desired, be set by a small brake. The press may be operated in its conventional manner, since with the worm wheel 16 immobilized, the brake housing is thus secured to the press frame and the brake acts as if the brake housing were integral with the press frame.

When it is desired to inch the press, the main press control is not employed at all. A separate inching control which is very simple and may consist only of a reversing starter adapted to control the motor 44 and push buttons marked Inch forward and Inch reverse (not shown). When the motor 44 rotates, it will drive the worm 36 in one direction or the other depending on the direction of rotation of the motor 44. This will rotate the worm wheel 16 and its attached brake housing L3 to which the drive shaft of the press is clutched by means of the brake, which is in set position. Accordingly, the drive shaft 24 of the press will rotate, thereby elevating or lowering the slide. Since the pitch of the worm is quite small, this motion will be correspondingly slow, thus enabling a very accurate positioning of the slide, which is extremely advantageous in all operations in which inching is desirable.

It will be observed that it is not necessary to return the brake housing 14 to any particular position before the press can be again operated through its operating controls. The operation of the clutch and the brake of the press depend upon the rotary cam limit switch (not shown) which is driven from the gear train of the press and is hence always synchronized with the position of the ram, as is well known in the art. During the normal operation of the press there is considerable torque on the brake housing each time the brake is engaged. In this invention, the shock of stopping the press is borne by the worm gearing. It will be understood in the art, therefore, that this gearing will be suificiently strong and rigid to take the shock loads. Thrust bushings and 37 are provided at each end of the worm 36 for transmitting the brake shock to the frame It through the member 12. The

passageways

31 and 33 in the brake housing and the openings 29 in the brake disc 26 are provided for the passage of cooling air. The bearing 23 supports the drive shaft in the press frame 10.

It will be seen that I have accomplished the objects of my invention. I have provided an inching assembly for rapidly, conveniently, accurately and expeditiously inching the press in either direction without resorting to coupling the ram of the press with the flywheel of the press. This enables me to inch the press accurately and is especially advantageous in a press designed for high speed operation.

It will be understood that certain features and subcombinations are of utility and may be employed Without reference to other features and subcombinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details Within the scope of my claims without departing from the spirit of my invention. It is therefore to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. In a power press, a frame formed with an annular chamber, a drive shaft rotatably mounted on the frame. a brake housing formed with an integral flange, said flange being positioned in said chamber and forming means for rotatably mounting said brake housing for rotary motion relative to the frame, a brake disk carried by the drive shaft for rotation therewith, a brake plate stationary relative to the brake housing and carried thereby, a brake plate movable relative to the brake housing and carried thereby, means for moving the movable brake plate to clamp the brake disk between the brake plates to immobilize the drive shaft with respect to the brake housing, means normally preventing said rotary motion of said brake housing, said brake housing flange being formed with worm gear teeth, a shaft rotatably carried by the frame, a worm carried by said shaft for rotation therewith and in mesh with said worm gear teeth, an electric motor carried by the frame, and means for coupling the output of the electric motor to the worm shaft whereby to form means for rotating the brake housing with the brake set when it is desired to inch the press.

2. In a power press, a frame, a drive shaft rotatably mounted on the frame, a brake housing formed with a flange, means for rotatably mounting said brake housing for rotary motion relative to the frame, a brake disk carried by the drive shaft for rotation therewith, a brake plate stationary relative to the brake housing and carried thereby, a brake plate movable relative to the brake housing and carried thereby, means carried by the brake housing for moving the movable brake plate to clamp the brake disk between the brake plates to immobilize the drive shaft with respect to the brake housing, means normally preventing said rotary motion of the brake housing, said brake housing flange being formed with worm gear teeth, a shaft rotatably carried by the frame, a worm carried by said shaft for rotation therewith and in mesh with said worm gear teeth, an electric motor carried by the frame, and means for coupling the output of the electric motor to said worm shaft whereby to form means for rotating the brake housing with the brake set when it is desired to inch the press.

3. In a power press, a frame, a drive shaft rotatably mounted on the frame, a brake housing formed with a flange, means for rotatably mounting said brake housing for rotary motion relative to the frame, a brake disk carried by the drive shaft for rotation therewith, a brake plate stationary relative to the brake housing and carried thereby, a brake plate movable relative to the brake housing and carried thereby, means carried by the brake housing for moving the movable brake plate to clamp the brake disk between the brake plates to immobilize the drive shaft with respect to the brake housing, means normally preventing said rotary motion of the brake housing, said brake housing flange being formed with gear teeth, a shaft rotatably carried by the frame, gear driving means carried by said shaft for rotation therewith and in mesh with said gear teeth, an electric motor carried by the frame, and means for coupling the output of the electric motor to said gear driving shaft whereby to form means for rotating the brake housing with the brake set when it is desired to inch the press.

References Cited in the file of this patent UNITED STATES PATENTS 2,319,231 Hawley May 18, 1943 2,581,941 Shinn et al Ian. 8, 1952 2,586,617 Danly Feb. 19, 1952 2,598,633 Baldwin May 27, 1952