US2081709A - Control mechanism for hoisting machines - Google Patents

Description

May 25, 1937. D. A. MATOT CONTROL MECHANISM FOR HOISTING MACHINES Filed July 19, 1935 IEmlL 0 Patented May 25 1937 UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR HOISTING MACHINES 7 Claims.

unable to determine the position of the car afte it had left his level. In many instances, the upper and lower limits of the car guides determined the limits for its movement, and as the car reached these limits, it would come to a very abrupt stop and exert a strain on the guide rails, the car, and the structure supporting the same.

It is an object of this invention to provide means for automatically determining the limit movements of the car within the range of its movements, whereby the car will be brought to a stop with the least amount of tension and strain exerted on its driving mechanism and without requiring the skill of the operator to determine its limit of movement.

A further object is the provision of control mechanism for rendering the driving mechanism inoperative at predeterminedintervals during its normal operations.

And a still further object is the provision of control means effective by the operation of the driving mechanism for rendering the same inoperative with its source of power.

Various other and further objects and advantages will become apparent from the ensuing description and. claims.

Referring to the drawing:

Figure 1 is a side elevation of a hoisting device or dumb waiter embodying my invention.

Figure 2 is an enlarged top plan view of the control mechanism with a portion of the hoisting device broken away. 7 Figure 3 is a detail top plan view similar to Figure 2 illustrating a changed position of the control mechanism. 7 t

Figure 4 is a top plan detail'view similar to Figure 2 illustrating a geared driving mechanism which is rendered inoperative upon the movement of thecontrol mechanism.

Figure 5 is a detail cross-sectional view taken substantially on the line 55 of Figure 2, showing the positive stop means of the control mechanism.

Figure 6 is a detail cross-sectional view taken substantially on the line 6-6 of Figure 2, showing the actuating means for the control mechanism and the means that predetermine the operation of the device.

Figure 7 is an enlarged fragmentary detail sectional view of the actuating means coacting with the control mechanism.

Figure 8 is a detail cross-sectional view of the clutch means coacting with the control mechanism, taken on the line 8-8 of Figure 2; and

Figure 9 is a vertical sectional view taken on the line 9-9 of Figure 8.

The reference numeral l designates a cage which is provided with the usual guide rails H on which a car I2 is slidably guided. The cage I0 is provided with a plurality of relatively small sprocket gears i3, l4, l and I6, which are pivotally carried on a top structure ll formed of angle iron or the like.

The control mechanism, designated as a Whole as i8, is preferably secured to the cage structure I0 and has a relatively long chain l9 extending therearound, with one end 20 thereof extending over-the sprockets I3 and [5, with its free end extending downwardly and fixed to the top of the car I2 at 2|. The other end 22 of the chain extends over the sprockets I4 and i6 and is secured to a weighted member 23 which serves to counterbalance the car l2.

The control mechanism I8 is secured to the cage I0 and has a pair of brackets 25 and 26 which support a transversely extending shaft 21 that is journalled therein and which has a sprocket gear 26 loosely mounted for turning movements thereon and around which the chain l9 extends to elevate and lower the car l2 in the cage In. An engageable member 29 is secured to the shaft '21 and is provided with a cut-away portion 30 forming spaced-apart shoulders 3| and 32 thereon, which are each provided with a resilient pad 33 and 34, respectively, which are adapted to engage a horizontally extending bar 35 pivotally carried for swinging movement on the bracket 25 at one end thereof by means of a pin 36, and is normally urged in one direction by means of a spring 31. The bar 35 is provided at its free end portion with a transverse pin 38 that extends through an elongated slot opening 39 adjacent one end of a relatively long arm member 40 that is pivotally carried for rocking movements on a bolt 4| on a bracket 42 positioned intermediate the brackets 25 and 26 of the control mechanism I8. The arm member 46 extends outwardly of the bracket 42 and is provided on its free end portion with a 2-way receiw'ng cam 43 that is disposed in the chain 19 thereon. This chain l9 has the roller members 44 that are adjustably positioned thereon and retained in position by means of the frame members comprising side plates 45 which are provided with openings 46 and 47 therein through which the studs 48 and 43 of the links of the chain I9 extend. These rollers 44 may be secured in any predetermined position on the chain 19 and serve to automatically engage the receiving cam 43 during the movements of the chain to effect a rocking movement of the arm 43 on its pivot 4| and an inward swinging movement of the bar 35 on the pin 36 against the tension of its spring 31 until this bar 35 has assumed the position shown in Figure 2 within the reduced portion 3!] of the engageable member 23 and into the path of either of the cushions 33 or 34, depending upon the direction of rotation of the shaft 21.

It will be noted that the device is capable of being adjusted to Vary the positions at which the car may be stopped. The engageable member 23 is adjustably positioned on the shaft 27, and'the cut-away portion 35 thereof is aligned with the roller 44 of the chain 25 after the stopping position of the car has been determined, so that as this roller 44 engages the receiving cam 43 the bar 35 will be'brought into the recess 33' in timed relation with the turning movements of the engageable member 29 and permit of a relatively short turning movement thereof before either the cushion 33 or 34 engages the bar 35, dependent upon the direction of rotation of the shaft 21.

A clutch member 55 is carried on the shaft 21 and is connected to the sprocket gear 23 and operatively connected with the shaft 21 in either direction of its movements, and this clutch also serves to retain the car in locked position at its limit of movement and during the time the engageable member 23 has engaged the bar 35.

The clutch member 50 comprises a drum 5| that is loosely carried on the shaft 21 and has a brake band 52 engaging the inner periphery thereof and retained in position by means of a wedge 53. The band 52 is of a U-formation, having its free end formed to provide a tapered opening 54 into which the end 55 of the wedge 53 normally extends. This wedge 53 is'provided with an elongated slot opening 55 and is bodily car ried for reciprocating movements on a shoulder 51 of an actuating member 58. A compression spring 55 is interposed between the actuating member 58 and the wedge 53 in the elongated slot opening 55 and serves to retain the end 55 of the wedge in retracted position while in the opening 54 formed by the adjacent endsof the band 52. The wedge 53 is provided with outwardly directed portions 59 that extend on each side of the shaft 27 and are adapted to be engaged by an integral cross arm 60 on the actuating member 58. The actuating member 53 is keyed to the shaft 21, and when this shaft is turned, the member 58 will be turned therewith until the cross arm thereof engages either of the outwardly extending portions 59, which will move the wedge outwardly and cause the end 55 thereof to be forced into the opening54 and cause a spreading action of the brake band 52 against the inner periphery of the drum and grip the same for turning movement with the shaft 21. A retaining means (not shown) coacts with the drum to retain the same and to retain the car in the position to which it has been moved.

The drum 5| is provided with an outwardly extending hub 6| that is provided with a tongue portion 62 adapted to interfit a slotted portion 63 in the hub 64 of the sprocket gear 28 for driving the same therewith.

As thus far described, it will be seen that the turning movements of the shaft 21 cause the clutch member 53 to be gripped and turned therewith to, in turn, cause the turning movements of the sprocket gear 28 to drive the chain 19 and the car l2 in the cage ii]. And as one of the rollers 44 on the chain 59 engages the receiving cam 43, it will cause the movement of the bar 35 into the recess 35 of the engageable member 29 to be engaged by one or the other of the cushions 33 or 34 on the engageable member. This engagement of the cushions 33 or 34 with the bar 35 will cause an abrupt stop in the turning movements of the shaft 27 and release the clutch mechanism by relieving the driving strain of the actuating member 53 against the portions 59 of the'wedg'e '53 and will permit the compression spring. 55 to restore the wedge to its normal position and relieve the gripping strain on the brake band 52 against the'inner periphery of'the drum 5!. This action permits or a positivestop of the driven shaft 21 while permitting 'ofarela tively easy and cushioned stopping of the car with respect to its'flexible drive chain 19 to the sprocket gear 28.

The device is shown with a manual driving means in which a hand wheel 65 is'secured directly to the driven shaft 27.

Figure 4 shows a reduction gearing which has a large gear 66 fixed to the shaft 21 and which is inmeshing engagement with a smaller gear 61 fixed'to a shaft'68 that is supported in'the brackets 25 and 42 and which has a hand wheel 59 fixed thereto. This reduction gearing is for use with the heavier type of dumb waiters, and the operation of the control mechanism is in the same manner as above described.

I contemplate, as being included in these improvements, all such changes, variations and departures from what is thus specifically illustrated and described as fall within the scope of the appended claims.

I claim:

1. The combination of a hoisting device having a reciprocable car, of a driving means for reciprocating said car, a rotatable drivenmemberon said driving means, means engageable by said driving means for causing the said engageable means to extend into the path of rotation of said ing cam engageable by said driving means for eifecting movement of the engageable means into the path of rotation of said driven member in either direction of movement of saiddriving means.

3. The combination of a hoisting device having a reciprocable car, of a driving means including a driven shaft and a flexible connection extending from the driven shaft to said car, a member fixed to turn with said shaft, and engageable means adapted to be positioned into the path of turning movements of said member, said engageable means being under the control ofs aid'flexible drive connection, said engageable means comprising a breakjoint having yieldable means coacting therewith normally retaining thesarne out of the path of movement of said member, whereby said engageable means is engaged at predetermined intervals by said flexiblejoonnection for efiecting its movements into the path of movedriving means, and rockable means engageable by ment of said member.

4. The combination of ahoisting device having a reciprocable car, of a drive means including a clutch for reciprocating said car, said clutch being engageable upon the movement of the drive means, an engageable member on the drive means, a rockable member normally out of engagement with said engageable member, and means on the drive means effecting a movement of the rockable member in the path of movement of said engageable member for rendering the drive means inoperable and for effecting a release of the clutch in timed relation with the stopping of the device.

5. The combination of claim 4 hereof in which there are cushioning means on said engageable member for absorbing the stopping shock of the device.

6. The combination of a hoisting device having a reciprocable car and driving means for reciprocating said car, an engageable member on the said engageable member and normally out of engagement therewith, and means at predetermined intervals on said driving means coacting with the rockable means for effecting the movement of the rockable means into the path of movement of the engageable member for stopping said engageable member for retaining the same and the driving means.

7. The combination of a hoisting device having a reciprocable car, of a drive means including a clutch for reciprocating said car, said clutch being operable upon the movement of the drive means, a control mechanism for the drive means, and means on the drive means for actuating the control mechanism, said control mechanism comprising engageable means adapted to extend into the path of and forming a positive stop for said drive means whereby said clutch is rendered inoperable.

I DUFFY A. MATOT.

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