US1421565A - Power-transmission apparatus - Google Patents

Description

W. C. REED. POWER TRANSMISSION APPARATUS.

APPLICATION FILED APR 19, 1920. v

Patented July 4, 1922. A

In men for 02m Cff q an if it a a i I is. i

POWER-TRANSMISSION APPARATUS.

Application filed April 19, 1920.

To all whom it may concern:

Be it known that I, l VALTER C. Rnnn, a citizen of the United States, residing at Dal ton, in the county of Berkshire and State of Massachusetts, have invented certain new and useful Improvements in Power-Transmission Apparatus, of which the following is a specification.

The present invention relates to power transmission apparatus, and more particularly to apparatus for connecting the driving power of a domestic washing machine to a pump employed therein.

As the washing machine is continuously driven from a main driving shaft, and as the pump is needed only at short and comparatively rare periods, to reduce the water in the machine, it is desired to provide means to connect and disconnect the pump shaft and the main driving shaft this burden being added when the main shaft is running at full speed. As mechanism of the type stated is light, driven by a high speed motor, and must be essentially inexpensive in construc. tion and ruggedly durable in use, it is an object of the present invention to provide means by which the maximum load of the pump can be picked up quietly and without racking the mechanism. It is accordingly an object of the present invent-ion to provide a new and improved yielding connection between the driving shaft and the separate pump mechanism that shall be extremely simple in construction and yet adapted for the purpose. To this end, a feature of the invention resides in providing a stationary sleeve which constitutes a tubular bearing for the'rapidly rotating driving shaft, and a moving sleeve that is rotatably and slidably mounted on said stationary sleeve, which thus constitutes a bearing for the moving sleeve. The latter has at its end a stud adapted to engage the free tangentially or radially projecting end of a helical driv ing spring which is wound around thedriving shaft next to the stationary sleeve, and has its other end secured to the shaft. The pump is driven by a sprocket chain from the moving sleeve; When the latter is shifted endwise so that its stud gets into the path of the whirling projecting end of the spring, it engages that end, gradually tightens the spring coil by its inertia, and gradually picks up the speed of the spring as the spring gets stiffer. All of this operation Specification of Letters Patent.

Patented July 4t, 1922.

Serial No. 374,843.

thus described as being gradual is really very quick, but it is sufiiciently yielding and gradual as compared with a positive, unyielding, connection to be well adapted to the needs of a washing machine.

Other objects of the invention are to improve power transmission apparatus of the above-described character, rendering it simple, easily operable, noiseless, effective, cheap to manufacture and to assemble and durable. An illustrative embodiment of the invention 1s herein shown and described.

It is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable nov elty exists in the invention disclosed.

In the accompanying drawings:

Figure 1 is a plan, partly in section, of a washing machine driving apparatus con- StllCtfiCl according to the present invention; an

Figure 2 is an end elevation, showing the apparatus connected so as to drive a washing machine centrifugal pump.

The, washing machine, not shown, but typified by the fragment of frame 1, gear casing 2, and shaft 8, is driven from a main driving shaft 4 through a worm and a gear enclosed, according to well-known practice, in a worm-gear housing. The main shaft 4 is. continuously driven by motor 6. A centrifugal pump 8 is provided with a shaft 10 that it is desired to drive occasionally from the main driving shaft 4:. To this end, the shaft 10 is provided with a sprocket wheel 12 that is connected by a sprocket chain 1% to a driving sprocket wheel 16, adapted to be driven from the main driving shaft by the spring clutch now to be de scribed. The sprocket wheel 16 is fixed upon a sleeve 18 that is slidably and rotatably mounted around the main driving shaft and that is at its end provided with a driven stud 20 which constitutes one of the clutch members. In the present instance the sleeve 18 is mounted, not directly upon the driving shaft 4, but upon a tubular extension of the gear housing 21 that surrounds the shaft, constitutes a bearing therefor and serves also to retain packing and oil within the worm gear housing. The length of the chain is such as to permit the lateral displacement which is incidental to the sliding of the sleeve upon the shaft without requiring that the chain be disengaged from the sprocket wheels. The driven stud 20 projects parallel with the shaft and is arranged toengage with the free outward projecting end 22 of a helical spring 24. which is wound toward it for a few turns about the driving shaft 4 from an anchorage of its other end to theshaft at 26.

The outstanding end may preferably be hooked as at 23, by being bent into approximate parallelism with the circumference of the shaft at a distance far enough out therefrom to be Outside of the radial distance of the position of stud 20. This prevents the end of the. spring from slipping past its engaging stud as the outstanding end'of the spring becomes shortened, when engaged, by the spri'ngbeing wound more around its shaft. Upon the sleeve 18 being slid along shaft 4 to the left, Fig; 1, therefore, during the rotation ofthe shaft the sprocket 'wheel16 will come into the plane of sprocket l2, and the stud 20 will move into the path ofrotation of the end 22 of the spring so as to be engaged thereby; the hook 23 will catch the stud as illustrated; and thereupon the rotative movement of the driving shaft will be transmitted yieldingly, through the spring, the sprocket sleeve and the chain to the pump shaft 10. The operation is effected easily, gently and noiselessly and is attended with no injurious effects. The pump has to get'up-its full standard speed very quickly and the yielding effect helps tota-ke upwhatevershock may be imposed, rendering it particul'arly adaptable to the requirements heretofore stated.

The above-described mechanism is associated preferably withv a slip-clutch connection and a fiexiblecoupling which may be of any suitable design between the motor 6 and the main driving shaft 4. The flexible coupling is shown at 28 connecting the main driving'shaft to one element 30 of the slip clutch. The other element 32 of the clutch is directly connected to the motor. In case of'need'at the moment when the sleeve 18 is movedto the left Fl 1, to connect the pump to the driving shaft, the friction clutch will yield, tending further to reduce the initial shock, and incidentally also protecting the motor, The flexible coupling 28 which may be a length of heavy steam hose acts to compensate for possible transverse slight displacements of the shaft 4, so that power may be transmitted to the washing machine and to the pump simultaneously without strain,

and acts further to take up shocks due to vibration. There is no part which does not receive shock through an elastic medium,

when the stud 2O engagesspring 2a.

The sleeve 18 is adapted to be moved to the left, to engage its stud with the free pnojectingend 22of the spring, and to the right. to cause their disengagement, on which occasion the stud slips out sidewise from the hook 23, by a pawl 34 having a projecting portion 36 lying in a circumferential groove 38 on the sleeve. The pawl 3% is pivoted to a rocking arm 4-0 that is offset at right angles from the pivotal portion a2 of a pump control rod. The control rod 42 is provided with a handle (indicated at the left, Figure 2) whereby it may be rocked to either of two extreme positions indicated in full and dotted lines in Fig. 1. In the full line position, the pump is driven from the driving shaft. In the dotted line position, the pump is inactive. A tension spring 44 is fastened at one end to the offset arm at) and at its other'end is fast to the frame'of the machine, in such position that the straight line joining the ends-of the springrswings past a dead center position with respectto the rocking arm 40 of the pump control rod Q2. The 7 spring thus acts to maintain securely the arm vetO in either ofits illustrated positions, eliminating the possibility of the pump accidentally starting or stopping. The pawl 3a is supported by a bracket 46 secured to the gland 21. V v

In consequence, the sleeve 18 is held without friction while the pump is not in use, although it surrounds and is movable along the main shaft 4; and when moved it is held in engagement by the spring a4 and by the hooked end 23 of the clutch, and is subjected to wear only while thus engaged. 'The'interior of the stationary sleeve 21 may: or may not be a bearing for-the shafts, at the pleasure of'the designer, there being shown a slight clearance for'the shaft in Figure *1; and this stationary sleeve 21 may be readily designed as a fiXedpart of other mechanism, the same beingused in the present case as a gland to hold packing-in place.

The construction of the whole; is extremely simple, as regards expense, as is'manifest by. observing the extreme simplicity of the clutch spring arrangement, and introduces an element of elasticity by which the pump 110 can be connected abruptly, so far as the operator is concerned, at any time without the complication ofan ordinary clutch and without the ordinary incidental shock. V \Vhen the apparatus is designed for the purposes 115 stated, the spring may have about'five turns of its helix on the shaft, and has abundant strength and elasticity if made up of wire about in diameter;

The invention having been thus described .120

what is claimed as new is:

1. In combination, a shaft, a; sleeve rotatably and slida-bly surrounding it, having a. driven stud, a helical driving spring loose on the shaftv with one end fastened. to the shaft and with its-other end free and extendingoutw-ar-d from the shaft in direction to engage and disengage freelya bodyrotating about the shafts axis, and means for sliding the sleevealong the shaft to move the driving stud into and out of engagement with the free end of the spring.

2. In combination, a shaft, a sleeve rotatably and slidably surrounding it, having a stud projecting parallel with the shaft, a helical spring wound around the shaft, having one end fastened thereto and its other end extending outward from the shaft and formed as a hook outside of the position of and adapted to engage the stud; and means for sliding the sleeve along the shaft to move the stud into engagement with the projecting end of the spring between said hook thereon and the shaft, whereby the hook is drawn inward into engagement with the stud when the shaft rotates, and to slide the sleeve in the other direction with the stud slipping in the axial direction out from engagement with the spring.

3. In combination, transmission mechanism comprising a main driving shaft; a tubular stationary sleeve surrounding it; a second sleeve surrounding the shaft, rotatable and slidable on the first sleeve; means to slide the second sleeve on the first sleeve; a

wire spring coiled loosely around the shaft next to the sleeves, having one end fast to the shaft and its other end free and outstanding therefrom in position for engagement by the second sleeve when the latter is slid toward it.

Signed at Pittsfield, Massachusetts, this sixteenth day of April, 1920.

WALTER C. REED,

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