US 380294 A
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NQ. 380,294, Patentedlvw 27, lf
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UNITED STATES PATENT CHARLES F. MURDOOK, OF DETROIT, MICHIGAN, ASSIGNOR OF ONE-HALF TO JONATHAN K. WEBSTER, OF SAME PLACE.
SPECIFICATION forming part of Letters Patent No. 380,294, dated March 27, 1888.
Application led September 10, 1885. Renewed November 12, 1887. Serial No. 254,981. (No model.)
.To @ZZ whom it may concern.-
Be it known that I, CHARLES F. MUEDocK, of Detroit, in the county of Vayne and State of Michigan, have invented new and useful Improvements in Dynamometers; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this specification.
This invention relates to a new and useful improvement in dynamometers, especially designed to readily ascertain the force required in driving the machines in an industrial establishment. The dynamometer herein described belongs to that class in which a spring forms the medium for transmitting the power, and wherein the state of tension of n said spring is indicated on a scale on which are marked the degrees of static force corresponding to the tension of the springs.
My improvement consists in the peculiar arrangement and construction of the parts, all as hereinafter described,and pointed out inthe claims.
In the drawings which accompany this specication, Figure 1 is a perspective view of my improved dynamonleter. Fig. 2 is a similar perspective View, looking at the opposite side, and with some portions broken 0H or removed. Fig. 3 is a vertical central section.
A is the counter-shaft from which the power for driving the machinery is obtained. Upon this counter-shaft is secured the hollow shaft B, and upon this is sleeved a loose pulley, C, which is held between two collars, D E, made fast upon the shaft B. The pulley is provided with a hub, B', and a coil-spring, F, is sleeved upon the hub on one side of the pulley, with one end secured to the pulley at a and the other to the collar E at b.
H is a loose ring seated in an annular groove formed upon the hub of the pulley on the side opposite to where the coil-spring is placed. It is also provided upon its annular face with a pin or projection, I, and with a pointer, J, for indicating the position of this loose ring upon a scale, K, with which the adjoining part of the hub of the pulley is provided.
L is an arm secured to the periphery of the collar D, and adapted to engage upon its free end with the pin I ou the loose ring H, as shown in Fig. l.
M is a cap or coverfor the dynaniometerspring F. It is secured in any suitable manner to the collar E, as shown in Fig. 3, while in Fig. 2 it is shown detached.
In practice, when power is applied to the shaft A and a resistance to the face of the pulley O, (said resistance being furnished by the drive-belt) the dynamometer-spring F is put under tension, as it forms the medium between the power and the resistance. The degree of the tension required to overcome the resistance is indicated by the pointer .I upon the scale K, for it will be seen that the loose ring H, which carries the pointer, is turned in a degree corresponding to the tension of the spring by means of the engagement of the arm L with the pin I.
The loose ring H may be provided with a suitable tension device-such as the screw c to give it a little friction on its seat, so as to prevent its accidental displacement, without, however, offering any resistance to its turning freely whenever the arm L strikes against the pin I. The scale K is arranged to indicate the degrees of static force corresponding to different states of tension of the spring F.
It is obvious that if there is any uctuation in the power required to overcome the resistance the pointer .I indicates the maximum of power.
The dynamometric pulleyf7 as my device may be properly called, can be readily applied to counter-shafts of different size by making the bore of the shaft B to correspond; but it is obvious that the shaft B may form an integral part of the shaft A as far as the operation is concerned.
The collars D and E are preferably removably secured upon the shaft B by suitable setserews, or otherwise, so as to admit of adjusting the parts and facilitating the mounting or dismounting of the device. The cap M protects the dynamometer-spring from accidental injury.
In adjusting the device for taking a reading the loose ring H ought to be turned to bring the pin Iin contact with the arm L. The dynaniometer-spring is preferably of such power that its torsional range is only the arc of a circle.
My device is very simple. Its constructive form is very suitable for having the pulley Well balanced. It does not form a charge upon the power. It is of so compact form that it may take the place of an ordinary pulley, and it can be read when the machinery is at rest.
What I claim as my invention is- 1. In a dynamometer, the combination of a loose pulley provided with a hub, of a dynamometer coil-spring placed concentric to the shaft and forming the medium for transmitting by its torsional tension the power from the shaft to the pulley, of an annular scale on the hub of the pulley, and of a pointer carried by the shaft, so as to indicate the degree of torsion of the dynamometerspriug, all arranged substantially as described.
2. In a dynamorneter, the combination, with a loose pulley, a shaft, and a coil-spring,which forms the means of transmitting the power from the shaft to the pulley, of au indicator consisting of the arm L, a collar on the shaft, a hub on the pulley, the loose ring H, the pin I, pointer J, and the annular scale K on the hub of the pulley, all arranged and operating substantially as described.
3. In a dynamometer, the combination of the loose pulley C, the collars D E, fast upon the shaft, the coil-spring F, secured at one end to the collar-E and at the other to the pulley, the arnl L, secured to the collar D, and the loose ring H, having pointer J and pin I, and the annular scale on the hub of the pulley, all arranged substantially as described.
4. The combination, with the shaft A. the hollow shaft B, loose pulley C, having a hub, collar E on said hub, and the coil-spring F, placed around the hub of the said pulley, of the cap M, inclosing said spring and collar, substantially as described.
CHARLES F. MURDOCK.
J. K. WEBsTER, O. F. HEYERMAN,