US1701822A - Safety device for presses - Google Patents

Description

Feb. 12, -1929. 1,701,822

R. E. J. NORDQUIST SAFETY DEVIQ@ FQR PRESSES Filed May 9; 192s- 4 sheets-sheet 1 R. E. J. NORDQUIST SAFETY DEVICE FOR PRESSES Filed May 9. 1925 4 sheets-sheet 2 1 Feb. 12, 1929.l 1,701,822

R. E. J. NORDQUIST v SAFETY DEVICE Fon PREssEs Filed May 9, 1923 4 Sheets-Sheet 5 Feb.`1z, 1929.' f n '1,701,822

R. E. J. NORDQUIST SAFETY 1am/10E Fon PRESSES Filed' May 9, 1925 4 Sheets-Sheet 4 Patented Feb. l2, 19,29.

UNITED STATESPATENT OFFICE."

RONALD, E. J'. NORDQ'UIST, OF MAPLEWOOD, NEW JERSEY, ASSIGNOR TO AMERICAN CAN COMPANY, F NEW YORK,I N. Y., CORPORATION OF JERSEY.

SAFETY DEVICE FOR PRESSES.

. Application filed May" 9,

The present invention relates to safety devices for die presses of the type which are commonly employed for operating upon sheet metal stock and is principally directed to the provision ofsuch a device w-hich will positively require re-setting by the operator before each stroke of the press, and, as an incident thereto, the removal ofboth of the operators hands from the die, with consequent' 0 prevention of accidents.

I have observed that the safety, devices which have been erniployed in the past in connection with machines of this character, while perhaps effective if used as intended, are subject to being rendered ineffectual at the will of operators who have desired to avoid their use for the purpose of increasing production. Work on this type of machines o is frequently done at a piece rate, which often causes the operator to resort to various means of eliminating operations involved in controlling the machine, even at the sacrifice ofp safety. This has been accomplished, for eX- ample, by ltying down certain parts of the trip mechanism, which has been used to prevent the upper die and its associated parts from descending into the lower Ydie until such trip mechanism is operated to release a safety clutch. While means have been devised which require the operator to have his hands upon certain parts of thetrip mechanism.

at the time of throwing the press into operation, these have proven inadequate, due to the possibility of tying down the parts of the trip mechanism at one side so that at least one hand of the operator was always free forl handling the work and', therefore, in danger of being injured by the die parts.. The present mechanism is the first, so far as I am aware, which actually necessitates the use of both hands in resetting the safetyvdevice and, as a necessary incident. the removal of both hands from the danger Zone 5 A further object is the provision of a safety device of the foregoing eEective character which may be readilyl installed upon standard machines of the class indicatedand which involves a minimum number of parts and relatively small cost.

Numerous other objects and advantages of the invention will beapparent as it is better understood from the `following description, which, taken in connection with the accom- 1923. Serial No. 637,703.

panyingdrawings, discloses a preferred embodiment thereof.`

vReferringpto the drawings,

Figure 1L is a 'side elevation, partially broken away, of a machine in which my invention is embodied; A

Fig. 2 is an end elevation of said machine in which also certain parts are broken away for convenience in illustration; .j

Fig. 3 is an enlarged detail of the controlling means for the clutch operating mechamsm; j v

Fig. 4 is a horizontal sectional view, showing saidcontrolling means/in top plan;

Fig. 5 is a detail ofthe controlling means,

taken on the side opposite that shown in Fig. 3; andy I Fig. 6 is a horizontal sectional view, taken lsubstantially on the line 6--6 in Fig. 3.

The machine as thus illustrated comprises an adjustable frame 21, supported upon a base part 22 and carrying die parts, including a stationary membe/r 23 and an active member 24 which cooperate to perform the operations for which `the apparatus is designed. The stationary, of female, die part 23 is supported upon a block 25 positioned upon a forward extension 26 of the frame part 21and the active die member 24 is carried in a cross head 27 mounted upon a crank shaft 28 having bearings 29 and 3l in the frame. A brake 32 is provided on the shaft 28 and is adapted to be held under tension by means of a spring 33 positioned upon a -bolt 33 extending through the forward ends of the brake sections. This brak serves to positively stop each pressstroke `when desired and to prevent overthrow, this being a common construction in presses of this general character. The cross head 27 is mounted in the usual manner upon an eccentric portion 34 of said l shaft 28, which eccentric portion is mounted in cmnk members 35 upon the main portions of the shaft. A. pulley, or fly/wheel, 36 is mounted on one endbf said shaft 28 and receives power from any suitable source. The general press construction is ofthe common and Well-known type adapted to operate upon sheet metal articles, and itis believed that further description is, therefore, unnecessary.

The safety device provided by my invention will now be described.l This consists lil of two levers 37 an'd 38, which are'provided rendered ineffective by tying it down, or by at their forward ends with handles 39 and any of ,the usualdevicesremployed to defeat are turned upwardly at their rear ends and the purpose ofsuch parts. In order` that the operatively connected with the controlling clutch controlling devlces may be operated, 1t

mechanism of the safety device, in a manner iS also necessary that the level 38 be actu:

which will later be apparent. The lever 38,.`I fed t disengilge thi@ 16W-P46 IOIII the Stop which is at the left ofthe machine as shown Slu1 ler44 on the cam 43 and the mechanism in Fig. 2, is connected to a transverse shaft 4l, which extends througgh and has bearings in a box, or housing memser 42 secured to the frame by ,bolts 42', and L1n which are positioned certain parts shown in detail in Figs. 3 to 6, inclusive.

' Said parts include a cam 43, which is loosely mounted on said shaft 41 and which 1s provid-ed at the top with a stop shoulder 44 adapted to be engaged by a projection 45 on the forward end of a lever 46, which is pivoted at 47 to a block portion 48 provided on the inner side of the box 42. An arm 49 is secured to said lever 46 at a central point by means of a pin 5l upon which is also positioned a spring 52, having its forward end 53 c.

extending forwardly and engaging over a stud 54 provided upon the side of said lever 46. From the pin 51, said spring extends downwardly and has itslower end 55 hoked about `a stud 56 on the lend of the arm 49. lVhen so mounted, said spring tends to fo'rce the levenl 46 downwardly and the arm 49 to ward the cam 43. A leaf spring 57 is secured by bolts 58 to the top of the box 42 and bears upon the top surface of said` lever 46.

whereby this is accomplished is perhaps best illustrated inFig. 5. It will be noted that the arm 49 has a block 67 secured theretolby means o'f bolts 68, and this block is engaged by a block 69 which is hooked at its'outer end, as shown at 71, and is secured by means of bolts 72 to a lateral projection 73 on a collar 74 rigidly secured to the shaft 41 by a pin 7 5. Rotation of the shaft 41, by actuation of the lever 38, serves, through this mecha- (nism, to lift the arm 49 and to disengage the lever 46 from the cam 43. With the parts in theposition illustrated in Fig. 5, the collar 59 and arm 62 are free for actuation by the lever 37.

The mechanism whereby the poweshaft 28is released for operation by manipulation of the lever 37 has not been shown in detail, since it forms no part of the present invention, but will be sufficiently understood by reference to Fig. 1. The'link63 is connected to an arm 7 6which is secured at its upper end to a short shaft 77 mounted in the frame and carrying also an upwardly extending arm 78, which is pivotally connected to a link /79, in turn pivotally connected at itsl upper we y. Referring now'part-icularly to Figs. 4 and end t0 a Shdmg 10d 8L Sad rod 81 eX' 6, it will be observed that thecam 43 is tends through a sleeve 82 and carries, at its loosely mounted'on the shaft 41 and has a cupper end a' roller 83 following a @am 84 Se collar 59 secured thereto by means of rivets 61, said collar being formed integrally with an upwardly extending arm 62, which protrudes beyond the top of the box 4.2,and is pivotally connected at its upper end to a link l, 63. Said a m62 is provided above the top of the box 42 with a hood part 64, which forms a cover forca slot 64', in which said arm 62 operates. This prevents the operator from inserting an instrument into the box whereby he nnghtxrender the safety de- 1 vice inoperative. Said box 42 is forme-d of separate parts, whichare secured together. by means of bolts and it will be obvious that the mechanism is thus protected against tampering bythe operator. "Said 'collar 59 is also formed integrally with a lateral extension 65,y which surrounds the end of the shaft 4,1 vand protrudes beyond the Side 0f sald box 42. The upper end of the lever 37 lis provided with a split bearing 66, surrounding said extension 65, whereby operation of said lever rotates the collar 59 and cam 43 andv rocks the arm 62 to actuate a safety clutch on the shaft 28 in a manner to be hereinafter described.

The operation of the lever 37 re uires the operator to remove one hand from is work and, as will later appear, this lever cannot be cured to tlieshaft 28. Said rod 81 is provided beneath the roller 83 with a projection, or hook, 85, which is adapted to engage' a knife blade cam 86 by which a safety clutch lon the shaft 28 is controlled. Said cam 86 acts in a slot formed in a pin 87, which is under the tension of a spring tendingto force it into a part of the constantly rotating fly wheel 36.` Said pin is positioned within a 'part secured to the die operating shaft`28 and, when in engagement with the Hy wheel, serves to connect said wheel and shaft for operation of the die. With the cam 86 in the .position shown in Fig. l, however, the pin 87 is withdrawn from engagement with the iy wheel 36, permitting the latter to rotate idly upon said shaft 28. Downward movement of the rod 81 serves to draw 4the cam 86 downwardly, permitting the pin 87 to be moved to position connecting the fly wheel 36 to the shaft 28. Said cam 86 is provided with a stem 88 extending through a sleeve 89 formed in a plate 91 secured to the frame 21, and a spring 92 is mounted upon said stem and normally holds the cam in upward position. When theshaft 28 is rotated to impart a stroke to the die member 24, the cam 84 acts upon the roller 83 to disengage the hook 85 from the cam 86, allowing the latter to be returned to normal position, forcing the pin 87 out of operative connection with the iy wheel 36. It is manifest that said hook 85 must again be raised to engage the cam 86 before another lstroke of the press can take place. This is accomplished by means of a spring 93, positioned upon the rod 81 in the sleeve 82, and by means of a spring 94 connected to the link 63 at one end and, at the opposite end, to a fixed point 95 on the frame. A spring 96, secured to the lower end of the rod 81 and to the frame 21, serves to hold the roller 83 in engagement with the cam 84, so that the hook 85 is in position to engage the cam 86, when permitted by said cam 84. Further operation of the lever 37 will again withdraw said cam 86 from operative engagement with the pin 87, permitting another stroke of the press.

In order that the lever 38 must necessarily be operated prior to each stroke of the press, the cam member 43 is provided with a tail part 97, which \acts upon the stud 56 at the lower end of the arm 49'to move said arm outwardly andkto disengage the block 67 from the hook 71 on the arm 69.v This permits the lever 46 to drop into position engaging the stop shoulder 44 on said cam 43 and it will be manifest that said lever 46 must be again lifted before another strokey of the press is permitted.

The cam 43, beyond the shoulder 44, isV

provided with a series of teeth 98, which are engaged by the point on the lever 46 in the event that said lever is not completely lifted and held in raised positionduring the operation of the clutch releasing mechanism. In this manner the operator is positively required to operate said levers 37 and 38 just prior to the downward stroke of the die part 24, thus preventing injury from the latter.

A spring 99 is connected atone end to an arm 101 on the shaft` 41 and, at the opposite end, to a pin 102 on the frame and serves to raise the hand lever 38v after operation, and, as an incident to' this action, to restore the hook part 69` on the collar 74 to position to again engage beneath the block 67 on the arm 49 when the latter is in this lowered g position.

In order to operate the press it is necessary to operate the lever 38 first since lever 37 is locked by the lever 46. Operation of the lever 38 lifts the lever 46 through the hooked end of theblock 69 carried by thecollar 74 and shaft 4l'enga0fing the block 67, the projection or hook 45 being lifted free of the cam 43. This releases the lever 37 and permits .operation of the clutch as above mentioned since'the lever 37 is directly connected to the cam 43 and arm 62 as above mentioned.

'press which are Controlled by Clutch operating movement of the lever 37 moves the cam 43 in a counter-clockwise direction (Fig. 3) and while such movement may be through any desired arc, in the present embodiment the movement required is approximately 30. The tail part 97 of the cam 43 is arranged so that just after the clutch pin is released for press operation the block 67 carried by the link 49 will be disengaged from the hook 71 by the stud 56, also carried by the link 49, engaging the tail part 97 of the cam 43.

This permits the lever 46 to drop or be forced into contact with the cam 43 by the spring 57, the projection 45 making Contact therewith just back of the teeth 98. Since the hook 98 must be raised to again engage the cam 86 as above described, the lever 37 must be returned to normal position. In returning to normal position the lever 37 moves the cam 43 in a clockwise direction, the projection 45 on the lever 46 rides over-the teeth 98 for preventing a reversal of movement, and when the lever 38 is returned to normal position as shown (Fig. 2) the block 67 engages over, the block 69 to permit another operation of the levers 37 and 38 of the press.

It is thought that the invention and4 many of its attendant advantages will be understood from the foregoing description, and itl will be apparent that various changes may be made inthe form, construction and arrangement of the parts without departing from the spirit and scope of the invention, or sacrific-l ing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

1. In a safety device for controlling .the operation of presses and the like, the combination of altranverse shaft, a handle for one hand of the operator fixed on said shaft, a handle for the other hand of the operator loosely mounted on said shaft, means controlling the starting and stopping of the press which are controlled b and require the operation of both of said andles for each cycle of the press.

2. In a safety device for controlling the operation of presses and the like, the combination of a transverse shaft, a handle for one hand of the operator fixed on'said shaft, a handle for the other hand of the operator loosely mounted on said shaft, means controlling the'starting'and stopping of the and require the operation of both of said handles for each cycle of the press, and a housing-enclosing a lpart ofsaid shaft and essential parts of said controlling means.

- RUNALD E. J. NORDQUIST.

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