US2594909A - Mechanical trip control for presses - Google Patents

Description

April 29, 1952 v. GEORGEFF 2,594,909

MECHANICAL TRIP CONTROL FOR PRESSES Filed Nov. 3, 1947 4 Sheets-Sheet l e2 24 l6 Him 34 I l2 "[1 IP55 a ll 46 VHS/L GEOEGEFF HTTORNEY April 29, 1952 v. GEORGEFF MECHANICAL TRIP CONTROL FOR PRESSES 4 Sheets-Sheet 2 Filed Nov. 3, 1947 IN V EN TOR VHS/L GEOPGEFF BY L HTTORNEY April 29, 1952 v. GEORGEFF MECHANICAL TRIP CONTROL FOR PRESSES 4 Sheets-Sheet 3 Filed NOV. 5, 1947 INVENTOR April 29, 1952 v. GEORGEFF MECHANICAL TRIP CONTROL FOR PRESSES 4 SheetsSheet 4 Filed Nov. 5, 1947 INVENTOR Patented Apr. 29, 1952 MECHANICAL TRIP CONTROL FOR PRESSES Vasil Georgefi, Chicago, 111., assignor to Danly Machine Specialties, Inc., Chicago, 111., a corporation of Illinois- Application November 3, 1947, Serial No. 783,748 5 Claims. (Cl. 192 13s) My invention relates to a mechanical trip control for presses and more particularly, to an improved mechanical control for power presses, enabling single stroke, continuous and inching operations of a power press through a completely mechanical control system.

In the operation of power presses it is neces sary to control the press to permit it to go through a. single cycle once upon the actuation of the control in order to permit the finished work to be removed and a new blank to be inserted. In some operations, it is desirable that the press run continuously, there being sufficient time to feed a strip of stock between the actual work performing steps. Then, too, in removing and inserting dies or in adjusting dies, a control must be able to inch and stop it at any desired part of its cycle. Most of the controls for presses involve the use of electrical systems, comprising a plurality of relays and complicated electrical wiring. These systems are not only expensive but are susceptible to frequent breakdowns resulting from short circuits or deterioration of the contact parts of the relays. Their complicated nature is such that when trouble develops it is a time consuming task, first to locate the trouble, and frequently in its repair.

One object of my invention is to provide an improved mechanical trip control for presses capable of controlling the press for a single stroke U operation, continuous operation and inching operation as desired.

Another object of my invention is to provide a mechanical trip control for presses which when set for single stroke operation will not repeat its cycle.

Another object of my invention is to provide a safe, completely mechanical control for presses which is certain in its operation and capable of operating for long periods of time without repair or breakdown.

A further object of my invention is to provide a mechanical trip control for presses which is simple in its operation and inexpensive to manufacture.

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

In 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 views:

Fig. l is a side elevation of a power press fitted with a mechanical trip control according to one embodiment of my invention.

Fig.. 2 is a front elevation of a portion of the press shown in Fig. l drawn onan enlarged scale with parts brokenaway showing the mechanical trip control shown in Fig. 1.

Fig. 3 is an elevation viewed along the line 33 of Fig. 2 showing the position of parts. when the press is stopped and in idle position.

Fig. 4 is a View similar to Fig. 3 showing the parts with the control adjusted for a single stroke operation with the foot pedal in operating post tion.

Fig. 5 is a view similar to Fig. 3 showing the parts in the position they occupy at the instant after the control has operated to stop the press with single stroke setting.

Fig. 6 is a view similar to Fig. 3 with the control set for continuous operation showing the position of parts during the operation of the press.

Fig. 7 is a view similar to Fig. 3 with the controls set for continuous operation showing the position of parts'during the stopping of the press.

Fig. 8 is a view similar to Fig. 3 showing the position of parts during the inching of the press.

Fig. 9 is a front elevation of the lower part of the press shown in Fig. 1 drawn on a smaller scale showing the control foot pedal and pedal latch.

In general my invention contemplates the provision of a control system operating through the control of the valve governing the compressed air supply to the clutch and brake assembly of the press. In power presses it is customary to employ a continuously running flywheel adapted to he clutched to the operating train of the press or to be unclutched therefrom with the simultaneous setting of the brake.

In my control system I provide a linkage including a coupling member and a latching member together with timed means operated by the movement of a press part, for releasing the latch under predetermined conditions. Means are provided to set the control for continuous operation or for single stroke operation. With the single stroke setting the latch will be released, irrespective. of the position of the foot pedal, at a predetermined point in the cycle of operations. With the continuous setting of the controls, the press will run continuously as long as the foot pedal is depressed. Upon release of the foot pedal, the cycle will be completed and the press will stop at a predetermined point in the cycle of operation. With the inching control the latch is not permitted to perform its function. The valve will open-whenever the inching lever is operated and will immediately stop when it is released, thus permitting the press to be moved to any part of the operator of the press.

its cycle. In the case of the single stroke operation and the continuous operation, the press will always stop at a predetermined point in its cycle after completing it and will not repeat irrespective of any movement of the pedal until after the cycle has been completed. The construction is completely mechanical and all of the parts are sturdy, sure of operation and inexpensive to build.

More particularly, referring now to the drawings, a press indicated generally by the reference numeral I may be of any desired type, style or capacity. Mounted on a side wall I2 of the frame of the press, I provide a control valve I4 adapted to be operated by a control lever I6 to govern the passage of compressed air through pipe I8 to the clutch and brake operating assembly. It is to be understood that when the valve is opened, the compressed air will cause the motor to drive the press train by operating the clutch and releasing the brake.

On the other hand, when the valve I4 is closed, the springs of the clutch and brake assembly will operate to set the brake and release the clutch.

It is to be understood that I have shown my control is applied to operate a compressed air valve operating lever for purposes of illustration only and that my control is adapted to be used with any control member known to the art, such as a switch in the case of an electrically or magnetically operated clutch.

As shown in Fig. 1, the valve is in closed position and held in this position by means of spring 22 acting against bushing 24 carried by the operating lever I6 and reacting against stationary bracket 26 carried by the press frame. An operating rod 28 must move in the direction of the arrow to rotate the valve operating lever I6 in a clockwise direction against the action of spring 22 in order to open the valve.

The rod 28 is moved by actuating lever 30 of a control assembly indicated generally by the reference numeral 32 shown in greater detail in Figs. 2 to 8 inclusive. The assembly, in turn, is operated through a connecting rod 34 which is urged upwardly by the action of spring 36 acting through a collar 38 secured to the rod 34 and reacting against a flange 40 carried by a connecting assembly indicated generally by the reference numeral 42 and shown in greater detail in Figs. 2 to 8 inclusive. A connecting rod 44 is connected at its upper end by the assembly 42 to the rod 34 and at its lower end by the coupling member 46 to a foot lever 48 which is fulcrumed at its outer end around pin 50 and is provided at its opposite end with a foot plate 52 adapted to be depressed by The upper dotted line position of the lever 48 shows the position of parts when the press is at rest. The lower dotted line position of the same foot lever 48 shows the position it occupies when the press is started. Upon the depression of the foot pedal, the rod 44 will move downwardly pulling rod 34 downwardly against the action of spring 36 to pivot the actuating lever 30 in a counterclockwise direction to move rod 28 upwardly against the action of spring 22 as will be described more fully hereinafter.

The control assembly 32 is provided with a. trip lever 54 adapted to coact with a cam 55 which is rotated by shaft 56 of the press actuat ing train. An inching lever 58 is adapted to be operated by hand to pull rod 34 downwardly through a predetermined distance as will be described more fully hereinafter.

Referring now to Fig. 2, I secure a plate 60 to the shaft 56 for rotation therewith. Adjustably mounted upon plate 60 by means of bolts 62 I secure the cam 55. The cam is provided with a pair of slots 64 adapted to provide angular adjustment of the cam in order to permit the synchronism of the control mechanism with the operation of the press. The control assembly, which is indicated generally by reference numeral 32 in Fig. 1, comprises a pair of plates 66 and 68 between which are mounted a stationary pivoted pawl 10 and a reciprocating pivoted pawl I2, as well as the trip lever 54 and the actuating lever 30, together with pawl biasing means 74 and 16. The reciprocating pivoted pawl 1'2 is an impelling member adapted when pulled downwardly to rotate the actuating lever 30. The base plate 66 of the assembly is secured to the press frame I2 by means of bolts I8 and 86. A pivot pin 82 is carried by the base plate 66 around which I pivotally connect the stationary pivoted pawl III. The upper end of connecting rod 34 terminates in a strap 84 which coacts with the lower bifurcated end 86 of reciprocable pawl or impelling member I2, being pivotally connected thereto by means of pin 88. The impelling member 12 is provided with a slot 90 through which the pin 82 passes and around which the pawl I0 pivots. The stationary pawl I0 is urged to rotate in a clockwise direction as viewed in Fig. 3 by means of a spring 92 which is housed in the member '14 and acts against bracket 94 secured to the base plate 66 by means of screws 96. The spring 92 is lodged about a pin 98 carried by the bracket 94. The biasing member 16 is similar in construction to the biasing member I4 and urges the reciprocable pivoted pawl I2 to rotate about its pivot pin 82 in a clockwise direction. The upper end of the stationary pawl 'II! is provided with a lug I00 which extends across a portion of the reciprocable pawl I2, as can be seen by reference to Fig. 2. The construction is such that a clockwise rotation of the pawl 10 will constrain the reciprocable pawl to move in a clockwise direction. The construction, furthermore, is such that when the reciprocable pawl moves in a counterclockwise direction the stationary pawl will be forced to move in a counterclockwise direction.

A pair of posts I02 and I04 are provided for the reception of screws I O6 and I58 to secure the cover plate 68 to the control assembly. A pivot pin I III is provided for the fulcrum of a trip lever 54. A follower roller H2 is pivotally secured to the upper end of the trip lever 54 by means of pin II4. The follower roller IIZ is adapted to coact with cam 55.

The upper end of reciprocable pawl I2 is bored to receive a shaft II6. Secured to the outer end of the shaft or formed integral therewith, I provide a bearing block III The upper end of the reciprocable pawl 12 is provided with a reentrant portion I20 in which the block H8 is adapted to seat when it is turned through a 90 angle from the position shown in Figs. 3, 4 and 5, as can be seen by reference to Figs. 6 to 8 inclusive in which the block is shown in the seated position. Secured to the end of shaft I I6 I provide a setting handle I22-which is pinned to the shaft [I5 by means of pin I24. A spring I26 biases the shaft II6 to move to the left as viewed in Fig. 3.

The position of bearing block H8 can be adjusted to form an extension of the surface formed by the right hand side of the reciprocable pawl 12. By rotating the shaft IIIS through 90, the bearing block I I8 may be moved to a position in which it is housed in the reentrant portion I20. In this position, when the reciprocable pawl I32 and I34. The plate is provided with a flange 40 against which the lower end of spring 35 is adapted to seat. Pivoted about a pin I35, I provide a plate I38. The lower end of rod 34 is connected to the plate I33 by means of member I40 and pin I42. The upper end of rod 44 is connected to the plate I38 by means of member I44 and pin I46. The lower end of rod 44 is connected by coupling member 45 and pin I45 to the foot lever 48.

Referring now to Fig. 9, a pivoted locking member I48 is pivotally secured to the frame of the press by bolt I58. lhe locking lever I48 is provided with a weight I52 which normally pivots the locking lever to position shown in Fig. 9, that is, the unlocked position. A shoulder I54 is formed adjacent the lower end of the lever I48 adapted to coact with the foot pedal 52 as shown by the dotted lines in Fig. 9, to hold the foot lever in depressed position for continuous running.

Referring again to Figs. 2 to 8 inclusive, the inching lever 58 is pivoted about pin I35 and is adapted to contact a member I4I carried by pin I42 as can readily be seen by reference to Fig. 2. A stop I56 is carried by the plate I33 to limit the lower position to which the inching lever can be moved. The inching lever is shown against the stop in Fig. 8. The position of the stop is such as to limit the motion of the reciprocable pawl downwardly to prevent the latching of the actuating lever by thestationary pawl 19-.

In operation, referring now to Fig. 3, in which the parts are shown in idle position with the press stopped, the bearing block II8 has been adjusted to the single stroke position, the valve I4 is closed, the actuating lever being in the position it occupies when the valve i closed. The toe of the actuating lever 35 is engaged with the projection of the reciprocable pawl I2. The foot pedal is in raised position being urged upwardly by the action of spring 35 acting through connecting plate I38 and rod 44.

Let us assume it is now desired to operate the press for a single stroke. The foot lever 48 is rotated in a counterclockwise direction by stepping upon foot pedal 52, thus pulling the rod 44 downwardly and rotating the connecting plate I38 in a counterclockwise direction. This pulls rod 34 downwardly against the action of spring 35, pulling the reciprocable pawl "I2 downwardly. Since the pawl I2 isengaged with the toe of actuating lever 33, it will rotate this lever in a counterclockwise direction, pulling the rod 28 upwardly against the action of spring 22 and rotating the valve operating lever I6 in a clockwise direction to open the valve. The stroke of the movement of the pawl 12 is such that it carries the toe of the actuating lever 33 downwardly past the upper portion of latching pawl It camming it to rotate in a counterclockwise direction around pivot pin 82 against the action of spring 52 exerted through pawl biasing member E4 and underneath the projection at the upper end of latching pawl Ill to hold the actuating lever 33 in the position shown in Fig. 4.- The valve being open permits compressed air to operate the clutch causing the press to run. It will be observed that if the foot pressure upon pedal 52 is released, the reciprocable pawl I2 will again move upwardly to the position shown in Fig. 3. The lower toe of the trip lever 54, it will be noted, contacts with the pawl itself as shown in Fig. 3 or the bearing block II 8 as shown in Fig. 4 when the bearing block is set for the single stroke position, and the foot pedal is held depressed.

As the press runs, it will rotate shaft 56 in a counterclockwise direction carrying the cam 66 around until it reaches the position shown in Fig. 5, in which the parts are shown with the foot pedal depressed but with the bearing plate I I8 set in single stroke position. The cam 55 has rotated the trip lever 54 in a clockwise direction so that its toe acting against bearing plate II8 pivots the reciprocable pawl 12 around pin 82 in a counterclockwise direction. The reciprocable pawl 12 in this movement engages the lug I03- carried by the latching pawl '40 and rotates this pawl in a counterclockwise direction, thus freeing the toe of actuating lever 36 and permitting the spring 22 to move rod 23 downwardly to rotate the valve operating lever I 5 in a counterclockwise direction to close the valve M. It will be observed that it is immaterial whether or not the foot pedal 52 is held in depressed position or not. The press will always stop after completing one stroke. The trip lever 54 acts against bearing block III! when the foot pedal is depressed and the trip lever 54 acts against the reciprocable pawl itself when the foot pedal is raised.

For continuous operation, the bearing block I 18 is housed as shown in Figs. 6 to 8 inclusive. Referring now to Fig. 6, in which the parts are shown with the press running and the foot pedal held downwardly by means. of the latch I48, it will be observed that the actuating lever 33 has its toe latched in running position by the pawl 13. The trip lever 54 is clear of the cam 55 so that rotation of the press will not actuate. the trip lever 54 to cause the reciprocable pawl 12 to be rotated in a counterclockwise direction. The housing of the bearing block H8 removes the surface through which the lower toe of trip lever 54 acts. The press will run continuously with the parts in the position shown in Fig. 6.

Let us now assume that it is desired to stop the press with the bearing block 9 i3 housed, that is. in the continuously running position. This is accomplished by releasing the foot lever latch I48 so that the pedal will move to its upper position as shown in '7. This permits the reciprocable pawl 32 to move upwardly to the position shown in Fig. '7. The upward motion of the reciprocable pawl cams the trip lever 54 to move in a counterclockwise direction raising the roller H2 into the path of the cam When the cam moves around to its predetermined position, it will rotate the trip lever in a clockwise direction around its pivot pin Hi3 forcing the reciprocable lever to rotate around its pivot pin 32 in a counterclockwise direction and carrying with it the latching pawl it through the lug I56 formed thereon, thus releasing the toe of the actuating lever 30. The press will stop at its predetermined position in accordance with the motion of the cam.

When it is desired to inch the press and move it to any desired point in its cycle, the inching lever is operated. Rotation of the inching lever in a counterclockwise direction around its pivot pin 36 will move the reciprocable pawl 72 downwardly carrying with it the toe of the actuating lever 30 causing it to rotate in a counterclockwise direction around its pivot pin 3| to lift the connecting rod 28 and thus operate the valve operating lever Hi. It will be observed, however, that the inching lever 58 has a predetermined limit of motion governed by the stop I55. This limit is such that the downward motion of the reciprocable pawl I2 is above that at which the toe of the actuating lever.39 would be latched downwardly by the pawl 10. The result is that when the inching lever is released the valve immediately closes. it is impossible to cause the press to run except when the inching lever is depressed. It will not complete a cycle unless the inching lever is held downwardly during the entire cycle. As soon as the inching lever is released, since the latching pawl 10 is ineffective, the valve will close under the influence of spring 22 which moves the valve operating lever 6 to rotate in a counterclockwise direction thus closing the valve.

It will be seen that I have accomplished the objects of my invention. I have provided an improved mechanical trip control for presses capable of controlling the press for a single stroke operation, continuous operationand inching operation as desired. My control is completely mechanical and is certain in its operation and capable of operating for long periods of time Without breakdown necessitating repairs. My mechanical trip control is simple in its operation and inexpensive to manufacture. The parts are sturdy and visible. My press can be accurately adjusted to stop the cycle within predetermined limits determined by the setting of the cam 55.

I have described my trip control with respect to presses for purposes of illustration. It is to be understood that my trip control may be applied to any machine driven by a primary mover through the agency of a fiy wheel and clutch such as machine tools, printing presses, hoisting equipment and the like.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. 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 departingfrom 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. A control assembly for power presses including, in combination, an actuating lever for controlling the press, an impelling member having operative engagement with said actuating lever, a detent adapted to hold said actuating lever in press operating position, a trip lever adapted to release said detent, means coupling said detent and said impelling member whereby movement of said impelling member in a predetermined direction will drive the detent to actuating lever releasing position, said impelling member being formed with a surface adapted to engage said trip lever when the impelling member is in press stopping position, adjustable means carried by said impelling member adapted selectively to be moved to a position engaging the trip lever when said impelling member is in press running position whereby the control assembly may be adjusted for single cycle operation or for continuous operation and means responsive to The arrangement is such that V the movement of a'press part for actuating said trip lever at a predetermined point of the press operation cycle.

2. In a control assembly for power presses, an actuating lever for controlling the press, a manually operable reciprocable member having engagement with said actuating lever and adapted to move it to press running position, a detent adapted to engage said actuating lever to hold it in press running position, a detent trip lever, means responsive to the movement of a press part for driving said trip lever, means carried by said reciprocable member coacting with said trip lever and means providing an operable connection between said reciprocable member and said detent to release said actuating lever in response to motion of said trip lever.

3. A control assembly for power presses including in combination a control member adapted to be actuated to control the operation of a press, an actuating lever for operating the control member, an impelling member having operative engagement with the actuating lever, a detent adapted to hold the actuating lever at press operating position, a trip lever adapted to release the detent, means coupling the trip lever and the detent, a cam for driving the trip lever, means for mounting the cam for movement as a function of the movement of a press part, manually operable means for moving the impelling member to start the operation of the press, said means coupling the trip lever and the detent including interengageable means carried by the impelling member and the detent and an adjustable surface carried by the impelling member adapted to contact the trip lever when the impelling member is in a position moving the actuating lever to press running position.

4. A control assembly for power presses including in combination a control member adapted to be actuated to control the operation of a press, an actuating lever for operating the control member, an impelling member having operative engagement with the actuating lever, a detent adapted to hold the actuating lever at press operating position, a trip lever adapted to release the detent, means coupling the trip lever and the detent, a cam for driving the trip lever, means for mounting the cam for movement as a function of the movement of a press part, manually operable means for moving the impelling member to start the operation of the press, said means coupling the trip lever and the detent including interengageable means carried by the impelling member and the detent and an adjustable surface carried by the impelling member adapted to contact the trip lever when the impelling member is in a position moving the actuating lever to press running position, the adjustable surface comprising a bearing block, means for supporting the bearing block adjacent the upper end of the impelling member, said upper end being formed with a recess and means for housing the bearing block in the recess to set the control for continuous operation.

5. A control assembly for power presses including in combination a control member adapted to be actuated to control the operation of a press, an actuating lever for operating the control member, an impelling member having operative engagement with the actuating lever, a detent adapted to hold the actuating lever at press operating position, a trip lever adapted to release the detent, means coupling the trip lever and the detent. a cam for driving the trip lever, means for mounting the cam for movement as a function UNITED STATES PATENTS of the movement of a press part and manually Number Name Date operable means for moving the impelling member 945,551 Knee Jan 4, 1910 to start the operation of the press, the manually 1,600,403 Dorman et a1 Sept. 21, 1926 operable means for moving the impelling memberv 5 1,655,617 Lindgren Jan 10, 1928 comprising a foot lever, a second manually ope'r- 1,681,646 Papas 21, 1928 able means for moving the impelling member 2,052,752 criley Sept 1, 1936 and a stop for limiting the motion of the second 2,204,710 strout June 18 1940 manually operable means to render the detent 2,217,332 Criley Oct 8, 1940 lnefiective to latch said actuating lever upon the 10 2,342,645 Criley Feb 29 1944 operation of the p ne m m er. 2,494,452 Pearson Jan 10, 1950 VASIL GEORGEEF.

REFERENCES CITED The following references are of record in the 15 file of this patent:

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