US620723A - Speed-indicator - Google Patents

Description

Patented Mar. 7, I899.

D. T. SHARPLES.

' SPEED mmcAmR,

(Application filed Dec. 8, 1897.)

(No Model.)

. a: i l I Witnesses.

( jaudi t Jr flw Inventor.

Attorney.

' form of my device.

llwrrn Starts DAVID T. SHARPLES', OF ELGIN, ILLINOIS.

SPEED -lilDlCATR.

SPECIFICATION forming part of Letters Patent No. 620,723, dated March *7, 1899.

Application filed December 8, 1897- Serial No. 661,173. (No model.)

To 60% whom it may concermy Be it known that I, DAVID T. SHARPLES, a citizen of the United States, residing at Elgin, county of Kane, State of Illinois, have invented certain Improvements in Centrifugal Speed-Indicators, of which the following is a specification.

My invention relates to an improved speedlndicator operating by centrifugal force.

it is especially applicable to machines intended to be run at a certain speed, any variation from which should be automatically indicated.

Heretofore speed-indicators have, been devised in which the centrifugal movement of a weighted member is made to operate through intermediate mechanism upon a suitable pointer. In myimproved device all intermediate mechanism is dispensed with, the centrifugally-moving member being made to serve directly as an indicator.

lhe invention is fully described in connection with the accompanying drawings and is specifically set out in the claims.

Figure 1 is a sectional elevation of one Fig. 2 is a plan view of the same. Figs. 3 and 4 are similar views of a modified construction embodying my invention.

Referring specifically to the construction shown in Figs. 1 and 2, A represents a casing, which, as shown, has a base-plate A, adapted to be attached to the spindle B which is to be speeded. "Within this casing, which is rotated with the spindle, is mounted a movable arm or disk C, which is adapted to serve directly as an index. This index arm or member is in the present construction pivoted at a point 0 to the casing, so that its free end 0 shall swing directly across the center of rotation of the whole device'that is, across the axis B. This free end 0 is weighted at 0', so that it will tend to move outward in the direction of the arrow under the influence of' the centrifugal force developed. by the rotation of the spindle. This centrifugal movement is regulated by a suitable spring, as S, the yielding of which allows the portion 0 of the index which is normally held in the position indicated in Fig. 2 to move toward the center B as the speed of rotation is increased.

It will be readily seen that at a certain speed of rotation a certain point of the portion 0 of the index member 0 will be directly at the center of rotation. If, therefore, a certain marking-as, for instance, a blue spot or circle fbe placed at this point, it will only be necessary to provide a sight, as a, at the center of the casing to enable the operator to see at a glance that the desired speed is being maintained. Othermarkings -as, for instace, a white one at e and ared one at 9 would indicate speeds respectively lessand greater than that indicated by the blue. It will be understood that any marking which is at the center of rotation will be seen as distinctly as though it were stationary notwithstanding the high speed at which the whole device may be rotated.

The tension of the spring may be varied so as to accurately regulatefthe movement? The sight (2. may be merely a central opening in the top of a metallic casing, as shown, preferably covered bya glass (1, so as to entirely exclude dust, dirt, 53C.

It is evident that the construction above described may be readily modified without departing from. the spirit of my inventionfor instance, as shown in Fi s. 3 and' l, where the index member 0 is in the form of aplun; ger-rod, hollow except at the head 0 and having a series of markings in the form ofbands c f g. This plunger, as indicated, is loosely mounted in a glass tube A which is lined diametrically in the main casing A, attachable to the spindle. It operates in a manner exactly similar to that previously described, moving outward centrifugally against a spring S and showing at the center a the marking which corresponds with the speed of rotation. Other modifications may be readily devised. For instance, the casing may be fixed instead of rotating with the frame which carries the centrifugal index member. Also the spindle 13, instead of being rotated, may

be fixed and the indicator mechanism rotated upon it. The markings on the centrifugal index member need not be arranged to swing over the true axial center, as described, but

may be made to enter the sight provided in any desired manner adapted to show directly the position of the same and thereby indicate 5 the speed of rotation.

What I claim is 1. A speed-indicator having an index member arranged to be rotated bodily with the object to be speeded and to directly indicate by its centrifugal position the speed of rotation, substantially as set forth.

2. A speed-indicator having a casing with a sight in the face thereof and an index memher having a centrifugal movementinto said I 5 sight, substantially as set forth.

3. A speed-indicator having a casing with a sight at the center of rotation and an index member having a centrifugal movement into said sight, substantially as descri 4. A speed-indicator comprising a rotary I0 casing with central sight, an index member mounted therein and having a. mark ormlrb ings thereon adapted to swing centrifu'gflly' in presence of two witnesses.

. DAVID T. SHARPLES- Witnesses:

K. E. MoREY, C. S. GARLISLE.

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