US1657499A - Stop mechanism for presses - Google Patents

Description

Jan. 31, 1928. 1,657,499

J. DERRY 4 STOP MECHANISM FOR PRESSES F iled Oct. 20. 1924 2 Sheets-Sheet 1 I A III All. W

by MQLA\&N\ ATT YE- Jan. 31, 1928. 1,657,499

J. DERRY STOP MECHANISM FOR PRESSES Fild on. 20,1924 2 Sheets-Sheet 2 N NT 'V y JZWQQ wflw lkwifld.

A T RP' Y? Patented Jan. 31, 1928.

UNITED STA;

1,657,499 PATENT OFFIQEZ.

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STOP MECi-EANISM FOR PRESSE S.

Application filed October 20, 1924. Serial No. 744,862.

This invention relates to mechanically operated power presses. and has for its object to provide simple and effective mechanism tor auton'iatically stopping the press when the ram or movable press element reaches the limit of its movement away from or toward the bed or stationary element, in the one case to permit the ready insertion and removal of the work, and in the other to hold the work under pressure, and for permitting the press to be manually started after having been automatically stopped in either position.

The more particular objects of the invention together witlrmeans whereby the latter may be carried into eflect, will best be understood from the followingdescription of one term or embodiment thereof illustrated in the accompanying drawings. It will be understood, however. that the particular construction described and shown hasbeen chosen for illustrative purposes merely, and that the invention, as defined by the claims hereui'ito appended, may be otherwise practised without departing from the spirit and scope thereof.

In said drawings:

Fig. l is a plan View of a press having stop mechanism en'ibodying the invention.

Fig. 2 is a sect-ion taken substantially on the line 2-2, Fig. 1.

Fig. 8is a section taken substantially on the line 83, Fig. 1, but showing the parts in a slightly different position to illustrate the operation of the stop mechanism.

Fig. & is a detail section takensubstair tially on the line it-14, Fig. 3. y

The frame of the press, as shown. comprises a pair of side uprights 10 having shoulders 11 upon which are supported the lower ends of four upright rods or posts 12, said posts above their lower ends beingreceived and held in spaced upright position by hollow bosses 19 formed on the upper ends of the uprights. Adjacent their lower ends the posts 12 are threaded, as shownat 13, to receive nuts 1 1 by which is adjustably supported a bed plate 15, carrying the bed 16 or stationary element of the press. The rain 17, or cooperating movable element of the press, is formed with hollow bosses 18 which are guided upon theposts 12. The

ram l'iis moved toward and from the "bed' 16 by means of a toggle 20'interposedjbetween said rain and a crosshead2l carried by the posts 12. is herein shown, the crosshead 21 is slidably mounted on said posts and is normally held in engagement with nuts 22 on the latter by means of springs 23 interposed between said cross-head and nuts 2st on the upper ends of said posts, for the purpose more fully explained in a prior ap 'plication filed February 18, 1924, Serial No.

on a cam fast on the shatt 29, said cam operating to reciprocate the link 26 to nternately straighten and break the toggle.

Journalled in the uprights 10 is a trans verse main shaft 33 disposed substantially parallel to the cam shaft 29 and adapted to be rotated trom any suitable source of power,

not sho wn. Fast on the shaft is a pinion 8% (Fig. which meshes with a gear 35 fast on a countershatt 36, also journalled in the uprights 10 and disposed parallel to the main shaft 33. The countershaft 36 has splined thereto, for movement longitudinally thereof, a clutch hub 37 cooperating with asecond clutchhub 38 formed as part of a pinion 39 rotat-ably mounted on the countershaft 36 and ineshing'with a gear 4K0 on the cam shaft 29. The hubs 3T and38 constitute the elements of a clutch through which the cam shaft 29, and consequently thc mechanism for operating the ram 17, may be operatively connected with or disconnected from the main or power shaft The clutch hub 37 is movable. longitudinally of the countershatt 36 to connect and disconnect the clutch by means of a clutch fork 41 termed at the endof one arm of a l tshap ed lever4e2 pivoted at 43 to a transverse frame member l lconnecting the uprights 10, the other arm of said lever 42 being connected by a link 45 with a hand lever 1G p1voted at 47 to a lug l8 on one of the uprights 10 said hand lever 46 constituting means for manually operating the chit-cu iork or shitterdl to connect the clutch. y

T he clutch shli'tcr lever 42 is formed with an extension 49 provided with a cam roller 50 extended into the path oi movement of a pair of dogs 51 pivoted at 52 to one taco of the gear 40, said dogs having cam projections 53 for engaging the cam roller 50 and thereby operating the clutch shifter lever 1-2 to disconnect the clutch. The movement oi the dogs 51 011 their pivots 52 is limited by stop pins 5 1 and 55 projecting from the face ot' the gear 10, the pins 54: being located in advance of the pins 55 with reference to the direction of rotation of said gear as indicated by the arrows on Figs. 2 and 3. The dogs 51 are normally held in engagement with the pins 5% by means of springs 56 connecting the same with. pins 57 also projecting from the face of said gear, said dogs being however, adapted to yield against the tension of the springs 56 to the extent permitted by the stop pins f5. The dogs 51 move in synchronism with the cam 32, and their positions on the gear 40, as determined by the stop pins 55, are such, with reference to said cam, that when the toggle 20 is fully straightened or fully broken, thereby detel-mining the limits Of movement of the ram 17 toward and from the bed 16, the cam projection 53 of one of said dogs will engage the cam roller 50 and move the clutch shifter lever 42 on its pivot 43 to disconnect the clutch.

In operation, the hand lever 46 is moved on its pivot to connect the clutch, as shown in Fig. 1, thereby starting the press and causing a movement of the rain 1? to vard or from the bed 16, as the case may be. As shown in Fig. 2, the ram is moving away from the bed, and as it approaches the limit of its movement in this direction the cam projection 53 on one of the dogs 51 is brougl'it into engagement with the roller 50. Said dog thereupon yields about its pivot 52 and against the tension of the spring 56 until brought into engagement with its stop pin 55, as shown in Fig. 3 and in full lines in Fig. 4. At this time the rain 17 has substantially reached the limit of its l'l'lOVOll'lOIit away from the bed 16, and, the yielding movement of the dog 51 having been arrested by the stop pin 55, the cam projection 53 thereon operates to move the clutch shifter to disconnect the clutch and stop the machine. As soon as the cam roller 50 has been moved into the clutch disconnecting position, the cam projection 53 on the dog 51 will be snapped past said roller by the spring 56, as shown in dotted lines Fig. 4, thereby releasing said roller so as to permit the subsequent manual re-engagement ot the clutch when it is desired to start the machine. It will be understood that a similar stopping of the machine will be caused by the other dog 51 when the ram 17 reaches.

the limit of its movement toward the bed 16. In this manner the press is automatically stopped when the ram has been moved completely away from the bed in order to permit the ready insertion or removal of the worlr, and is also stopped when the rain reaches the limit o t its movement toward the bed to hold the work under Pl'QrSlllU, the stopping means being, however, ol sol-h character as not to interfere with the manual starting of the machine whenever desired.

Having thus described. my invent ion, claim:

1. In a power press, the combination with a bed and a ram, of mechanism including a rotary element and driving connections therefor for naming said ram toward and from said bed, means for discomiecting said driving connections, and dogs carried by said rotary element and having a limited yielding movement thereon for automatically operating said disconnecting means to arrest the movement of said ram when the latter reaches the limitoi its movement toward or from said bed.

2. In a power press, the combination with a bed and a ram, of mechanism including a rotary element and driving connections therefor for moving said rain toward and from said bed, a clutch for controlling said driving connections, a shifter for said clutch, a dog carried by said rotary element and having a cam surface for engaging and operating said clutch shifter to disengage said clutch, said dog being movably mounted on said rotary element, stops for limiting the movement of said dog, and a spring for normally holding said dog in engagement with one of said stops.

3. In a powerpress, the combination with a bed and a rain, of mechanism for moving said ram toward and from said bed, driving connections for said mechanism including a clutch, a shili'ter for said clutch, a pivoted dog moving in syncbronism with said mechanism and adapted to operate said clutch shifter to disengage said clutch when said ram reaches the limit of its movement, and a spring for snapping said dog past said clutch shifter when said clutch has been disconnected to permit manual operation oi? said clutch shifter to ire-engage said clutch.

4. In a power press, the combination with a bed, a ram, a shaft, and operative connections between said shalt and ram :ii'or moving the latter toward and from said bed, of a gear on said shaft, cooperating gearing including a clutch for driving the same, a shifter for said clutch, dogs carried by said gear and having cam surfaces adapted respectively to engage and operate said clutch shifter to disengage said clutch when said ram reaches the limit 01 its movement in either direction, said dogs being movably mounted on said gear, and s 'irinp's for snapping said dogs past said clutch slniter when said clutch has been disconnected to permit Pill till) manual operation of said clutch shifter to reengage said clutch.

5. In a press, the combination of a movahle press element, a driven shaft, mechanism operated therefrom for moving said element,

6. In a press, the combination of a movable press element, mechanism connected to said element for moving the same, a driven shaft, a rotary cam carried thereby for shifting said mechanism, driving means for said driven shaft including a clutch, a lever for operating said clutch, a device rotated from said driven shaft, and means for supporting said device to permit movement of the de vice in syi'ichronism with said cam to shift said lever and also to permit independent movement of said device after shifting said lever.

In testimony whereof I aiiix my signature.

JASPER DERBY.

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