US1100143A - Speed-controller. - Google Patents

Description

A. A. MILLER.

SPEED GONTRQLLER. APPLICATION FILED AUG. 11, 1913.

Patented Jun 16,1914.

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ARTHUR A. MILLER, 01? TACOMA, WASHINGTON.

SPEED-CONTROLLER.

Specification of Letters Patent.

Patented June 16, 1914.

Application filed August 11, 1913. Serial No. 784,205.

To all whom it may concern Be it known that I, ARTHUR A. MILLER, a citizen of the United States, residing at Tacoma, in the county of Pierce and State of Washington, have invented certain new and useful Improvements in Speed-Controllers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to machine elements, and more especially to centrifugal speed regulators; and the object of the same is to produce a speed controller which utilizes the centrifugal force of two radially movable sleeves mounted on a cross bar and retracted by spring power, in conjunction with stops movably disposed so that the sleeves strike against one or both of them, or neither of them, as conditions require, so that the rotation of the device is retarded more or less. This object is carried out by constructing the machine in the manner hereinafter more fully described and claimed and as shown in the drawings wherein- Figure 1 is a front elevation of a clock frame with my invention applied, the weights being shown in section and the parts standing in position where the governor strikes the brakes at two points; Fig. 2 is a similar elevation with the weights also in elevation, the parts being shown where the outer ends of said weights strike the brake at but one point; and Fig. 3 is an elevation similar to that shown in Fig. 2 with the parts so adjusted that the weights do not strike the brake at all. Fig. l is a fragmentary plan view, showing a detail of the rock shaft for setting the brake.

I will state that, while the drawings show my improved speed regulator as applied to a clock train and as rotating in a vertical plane, I do not wish to be limited to this use of the device nor to its disposition in such plane because obviously it could rotate in a horizontal plane, although in that case some of the advantages hereinafter re ferred to would not prevail. On this understanding, then, the controlling mechanism is mounted on the shaft S which usually carries the escapement wheel, although of course this might be any rotating shaft which was connected with the driving mechanism it is desired to regulate or control. This shaft should project beyond the frame F which in the present case contains the clock train T, and on its forward end said shaft carries a cross rod 1 constituting two arms bearing duplicated structures, and therefore I need describe but one. Of course this cross rod might be duplicated, and the two rods would then have four arms; but each arm is by preference constructed as follows: Thereon is loosely mounted a tubular weight or sleeve 2 capable of sliding radially outward on the arm when the shaft S rotates with sufiicient speed to set up centrifugal force within the sleeve. If the shaft S be horizontal as shown, each sleeve will tend to drop away from it when its arm passes below the shaft; but whether the latter is horizontal or vertical, each sleeve will have centrifugal force if the shaft rotates with sufficient rapidity. The sleeve is drawn normally inward toward the shaft, which is its axis of rotation, by means of a fine spring 3, so shaped or having such convolutions that it has considerable elasticity, and the outer end of this spring is by preference connected with the outer end of the sleeve whereas its inner end is connected with the shaft.

The numeral 4 designates a loop, herein shown as consisting of fine wire, connected at its outer end to the outer end of the sleeve and at its inner end to any suitable member such as the shaft itself or, as shown, the spring of the opposite device; and the purpose of this loop is to limit the outward movement of the sleeve, to which end the loop loosely embraces the spring at its inner end so as to give the sleeve some movement under cen: trifugal force. The device as thus far de= scribed especially if the shaft be uprightis a centrifugal governor and speed-controller, the centrifugal force being opposed by the contractile tendency of the spring. It is well known that the rapid rotation of such a structure would give these sleeves a tendency to fly outward, and the farther outward they move from their axis of rotation, the more rapidly they will move through the circle or path which they inscribe during the revolution of the shaft-first because of the resistance of the air the larger part through which they have to move, and second, because of the increased length of said path and their increased influence on the shaft by reason thereof. It is possible to regulate or to an extent counteract the controlling function which such a centrifugal speed governor would possess by supplying yielding means as described and tending to draw the sleeve or weight inward, and it would be possible to regulate the degree of such control by increasing or diminishing the forceof such springs, although in that case the drive shaft would have to be checked in its rotation or complicated devices employed to bring about such regulation. I havetherefore devised the following additional elements which act in conjunction with the parts set forth above.

The numeral 7 designates broadly a brake herein shown as a band or leaf spring having its body struck on a curvature much larger than the largest circle inscribed by the outer ends of said sleeves or weights, and then bent into two stops which are in the shape of humps 8 and 9, above and below the regulator as described above, and specifically disposed with relation thereto as yet to be described. What might be called the upper end of this brake is connected with a crank 10 on a shaft 11 which has a handle 12 so that it may be rocked to move the crank as illustrated; and what might be called the lower end of this brake is connected as at 13 with the frame F of the clock train T or with any other suitable part. The position and disposition of parts are such that by va riously setting the rock shaft by means of its handle, one or both or neither of the friction surfaces stops or humps in the same may be thrown into position to be struck by the outer ends of said sleeves or weights, at a time when they slide outward on their cross rods or supports, by reason of the rotation of the shaft on which they are mounted. By preference I would dispose the stop 8 so that with the device rotating in the direction of the arrow one sleeve strikes this stop first and the regulator is retarded thereby, then after it has passed this stop the other sleeve strikes the stop 9 and the regulator is again retarded thereby, and then the regulator must make almost a complete half revolution before the last-mentioned sleeve or weight strikes the upper or first stop 8, and the action is repeated. This disposition of parts I consider more effective in its results than if the regulators or weights struck the two stops simultaneously, providing of course that the steps were adjusted inward far enough .to cause them to be struck thereby.

The preferred disposition just described does'not interfere with the possibility of adjusting the entire brake by uteans of the rock shaft and its crank 10, so that one stop or both stops, or neither will be struck by the weights. The employment of this brakeespecially if it be a band spring as described-obviates the necessity for providing means for adjusting the tension of the springs above referred to, although of course it might be possible to use such adjustment in addition if desired. It is also quite obvious that it would be possible to mount the weights rigidly on the cross arm or arms of the shaft and retard their rapid revolution by means of a brake having two or more of the stops referred to, and in that case the centrifugal action would be missing, the fine springs and the limiting loops would not be necessary, one or more of the stops would have to be set into contact with the weights at all times, but the machine would be much cheaper. I might say that I prefer, however, to employ both the centrifugal feature of regulator and the retarding feature or brake, for the reason that the weigh-t of the sleeves when thrown outwardly by centrifugal force imparts a certain stability to the clock train T or other machinery even though said sleeves do strike the stop or sto as, which stability would not be present i' the weights were omitted and the outer ends of the cross arm struck the stop because in that case the machinery would be permitted to run forward intermittently or with short steps interspersed with periods of cessation or retardation, and the general effect would be irregular. It follows, therefore, that I call my device a speed-controller rather than a speed regulator, because the centrifugal feature first described will regulate the speed of itself (whet-her the fine springs be or be not adjustable in their tension), but with the addition of the brake mechanism the speed of the machine will be controlled even to the point of checking it altogether if the stops are set too far inward. The materials and proportions of parts, and other details are obviously not essential to the successful operation of the invention.

Further illustration than on the drawings will notbe necessary to show what would occur if the shaft S was vertical. In that case the sleeves or weights would fly outward equally and under the influence of considerable power when said shaft rotated, the action of the brake or retarding device would be the same as above described, and it would be immaterial which stop were employed if only one were to be used. hen

said shaft S is horizontal and the regulator l rotates in a vertical plane, however, if the shaft turns slowly it will be clear that the lowermost sleeve or weight will move farther outward from the shaft than the upperuzost because said lowermost is influenced 1 by its gravity in addition to its centrifugal force, and in that case I would prefer that the position of the pivot 13 and of the crank 10 be such that when the latter is adjusted the stop 8 be first thrown out of action and later the stop 9, the idea being that the last or lowermost stop be employed to retard the weight which slips downward on its arm by gravity in addition to centrifugal force.

What is claimed as new is:

1. A speed controller comprising a rotary shaft, a cross bar carried by said shaft, tubular weight-s slidably mounted on the arms of said bar, two angular leaf springs connected at their outer extremities with said weights and at their inner ends with said shaft and drawing the weights normally inward, loops connected at their outer end with said weights and having their inner ends embracing said spring for limiting the outward movements of the weights, a spring brake band to extend partially around the path of movement of the outer ends of said weights, one end of said spring being attached to a support, an intermediate portion of said band having a curved friction surface movable into and out of the path of movement of the outer ends of said weights, and a rock shaft having a crank connected to the free end of said band, substantially as and for the purpose set forth.

2. In a speed controller, the combination with a rotary shaft, a cross bar thereon, tubular weights slidably mounted on the arms of said bar, and yielding means for drawing said weights normally inward; of a spring brake band having a curved portion of greater diameter than the path traveled by the outer ends of the weights, said band also having a stop portion movable toward and from the shaft, and means for disposing said stop port-ion in the path of the outer ends of said weights while they are rotating.

3. In aspeed-controller, the combination with a rotary shaft, a cross bar therethrough, tubular weights mounted on the arms of said bar, and yielding means for drawing said weight normally inward; of a brake consisting of a curved band spring formed near its ends into two humps constituting stops standing in the plane of said weights, a pivotal support at one extremity of said spring, and an adjustable support for the other extremity thereof, for the purpose set forth.

4. In a speed-controller, the combination with. a rotary shaft, a cross bar therethrough, tubular weights mounted on the arms of said bar, and yielding means for drawing said weight normally inward; of a brake consisting of a curved band spring formed near its ends into two humps constituting stops standing in the plane of said weights, a pivotal support at one extremity of said spring, a rock shaft having a crank handle and a crank, and pivotal connections between the other extremity of said spring and the last-named crank whereby the stop nearest the same may be thrown radially outward from the shaft by turning the crank, and both stops may be thrown radially out.- ward by turning the crank further.

5. In a speed-controller, the combination with a rotary shaft, a cross bar therethrough, tubular weights mounted on the arms of said bar, and yielding means for drawing said weights normally inward; of a brake consisting of a band spring curved around more than half of the circle inscribed by the outer ends of said weights, and having bends in its body near. its ends, a pivotal support for one extremity of the spring, and means for adjusting the other extremity thereof radially to said shaft.

6. In a speed-controller, the combination with a rotary shaft, a cross bar therethrough, tubular sleeves slidably mounted on the arms of said bar, and yielding means for drawing said sleeves normally inward; of a brake consisting of a band spring pivotally supported at one extremity and having a hump in its body constituting a stop, and a manually operable rock shaft having a crank pivotally connected with the other extremity of said spring, the crank being of a length to throw said stop into the path of said sleeve, for the purpose set forth.

7. In a speed-controller, the combination with a horizontal shaft, a cross bar therethrough, tubular weights slidably mounted on the arms of said bar, and yielding means for drawing said weights normally inward with yielding force, and means for limiting the outward movement of said weights; a brake consisting of a band spring pivotally supported at one extremity and overlying the shaft, and a manually operable rock shaft having a crank pivotally connected with the other end of said spring, for the purpose set forth.

8. In a speed-controller, the combination with a horizontal shaft, a cross bar therethrough, tubular weights slidably mounted on the arms of said bar, yielding means for drawing said weight normally inward with yielding force, and means for limiting the outward movement of said weights; of a retarding mechanism comprising a band spring curved around the circle inscribed by the outer ends of said weights for more than half of said circle, a pivotal support for the lower end of said spring, a hump adjacent said support, a hump adjacent the other extremity of said spring, and means for adjusting this extremity, as described and for the purpose set forth.

9. In a speed controller, the combination with a rotary element; of a band spring pivotally supported beneath said element and having a hump adjacent said pivot; extending thence around more than half of a cirole around said element and having a hump my hand in presence of two subscribing witadjacent its other extremity, and means for nesses. adjusting the latter extremity to throw first the upper hump out of the path of said ele- ARTHUR MILLER 5 ment and then the lower hump out of said Witnesses:

path, for the purpose set forth. M. C. HEATH, In testimony whereof I have hereunto set C. W. SoHUH,

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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