US1208679A - Speedometer. - Google Patents

Description

M. SMITHEY.

SPEEDOMETER. Anucmon man SEPT-22, l9l6.

Patented Dec. 12, 1916.

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SPEEDOMETER.

Specification of Letters Patent.

Patented Dec. 12, 1916.

Original application filed. June 16, 1916, Serial No. 104,047. Divided and this application filed September 22, 1916. Serial No. 121,586.

To all whom it may concern:

Be it known that I, MARVIN SMITHEY, a citizen of the United States, and a resident of Lawrenceville, in the county of Brunswick and State of Virginia, have invented a certain new and useful Improvement in Speedometers, of which the following is a specification.

My invention relates to improvements in speedometers, and it consists inthe combinations, constructions, and arrangements herein described and claimed.

An object of my invention is to provide a novel form of speedometer in which a centrifugally operated member causes the movement of a slidable collar so as to transmit movement to a pointer or arm which moves over an indicating dial.

Other objects and advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claims.

' the My invention is illustrated in the accompanying drawings forming part of this application, in which Figure 1 is a face view of the meter; Fig. 2 is a horizontal section on the line 22 of Fig. 4 through the working parts of the speedometer; Fig. 3 is a section along the line 33 of Fig. 2, and Fig. 4 is a perspective view of the centrifugal operating devlce.

This application is a division of a prior application, Serial No. 104047 filed June 16, 1916. I

In carrying out my invention I provide a casing 1 which is cylindrical in shape. Disposed at the rear of the casing is a centrifugal device consisting of a shaft 2 which is mounted to rotate in bearings 3. Disposed at substantially the center of the shaft is a centrifugal wheel 4. As will be seen from Fig. 2, this wheel is pivotally mounted at 4 so that it may turn from the dotted line position shown in Fig. 2 to the full line position or vice versa.

The shaft 2 is provided with an enlarged portion 2*. Surrounding the shaft 2 on one side of the portion 2 is a spiral spring 5, which bears at one end on a slidable collar 6, the other end bearing on the portion 2. On the opposite side of the portion 2 is a similar spring 7, which bears at one end of portion 2*, and on the opposite end on a Slidable collar 8, I desire to call particular attention to the construction of these springs. It will be observed that they are made heavy in the central portion and lighter toward their ends.

The wheel 4 is connected with the' slidable collar 6 by means of a link 9, which is pivotally connected to the wheel at 9 in a slot 9 The slidable collar 8 is connected to the opposite side of the wheel by a link 10 which is pivotally secured at 10 in a slot 10 The collar 6 is provided with a groove 11 arranged to receive the spherical end 12 of a pivoted arm 12. The opposite end of this arm is formed in the shape of a segmental gear 13, which meshes with a pinion 14 on a shaft 15. The shaft 15, as will be seen from Fig. 1, bears an arm or pointer 16, which plays over a dial 17 indicating miles per hour.

The speedometer arrangement thus far described operates in the following manner: Normally, when the vehicle is at rest, the position of the parts is that shown in Fig. 2. When the shaft 2 is turned by means of flexible transmission mechanism 18 extending from the running parts of the vehicle to the shaft 2, see Fig. 11, the centrifugal force of rotation tends to move the wheel 4 from the full line position to the dotted line position, this movement being resisted by the spiral springs 5 and 7, since the movement of the wheel 4 tends to also move the collars 6 and 8 and therefore to compress these springs.

By making the springs larger and heavier in the center, the movement of the collar 6 may be such that its displacement will be in proportion to the speed of the vehicle, because it will be observed that the farther the spring is compressed, the greater resistance to compression will take place. It is a matter of experiment to determine the relative sizes and strengths of the end convolutions of the springs, as compared with their central convolutions, so that the movement of the collar 6 will be in exact proportion to the speed of the vehicle.

I claim 1. In a speedometer, a rotatable shaft, a ring or wheel pivotally mounted on said shaft, a pair of slidable collars disposed on said shaft, links connecting said collars with said wheel, said shaft having an enlarged portion near its center, and a pair of spiral springs disposed between said enlarged portion, and said movable collars, each of said springs having large convolutions and being made of relatively thick Wire, said spring tapering toward its ends and the diameter of each wire being relatively small toward the ends.

2. In a speedometer, a rotatable shaft, a ring or wheel pivotally mounted on said shaft, a pair of slidable collars disposed on said shaft, links connecting said collars with said wheel, said shaft having an enlarged portion near its center, a pair of spiral springs disposed between said enlarged portion and said movable collars, each of said springs having large convolutions and being made of relatively thick wire, said spring tapering toward its ends and the diameter of each wire being relatively small toward the ends, a movable pointer, and means connecting one of said movable collars with said pointer for shifting the latter in proportion to the movement of the collar.

3. In a speedometer, a rotatable shaft, a ring or wheel pivotally mounted on said shaft, a pair of slidable collars disposed on said shaft, links connecting said collars with said wheel, said shaft having an enlarged portion near its center, a pair of spiral springs disposed between said on larged portion and said movable collars, each of said springs having large convolutions and being made of relatively thick wire, said spring tapering toward its ends and the diameter of each wire being relatively small toward the ends, a movable pointer, means connecting one of said movable collars with said pointer for shifting the latter in proportion to the movement of the collar, said last named means comprising a pivoted arm, a. segmental gear carried by the arm, a pinion arranged to engage said segmental gear, and a shaft bearing said pinion and said arm or pointer.

MARVIN SMITHEY.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents,

Washington, D. C.

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