US2259792A - Reversing switch and rheostat - Google Patents

Description

H. w. BATCHELLER 2,259,792 REVERSING SWITCH AND RHEOSTAT Filed April 26, 1938 Patented Oct. 21, 1941 REVERSIN G SWITCH AND RHEOSTAT Hugh W. Batcheller, Newton, Mass., assignor to Standard Mfg. 00., Worcester, Mass., at corporation of Massachusetts Application April 26, 1938, SerialNo. 204,336 I (Cl. 201A-55) 1 Claim.

This invention relates to an electric rheostat switch for controlling an electric motor so that itcan be operated at various speeds in either direction. It is an object of the invention to provide a switch of this kind which is suitable for the control of the motor of an automobile heating unit or other equivalent accessory. Since a switch for such purpose is customarily mounted on the dashboard of an automobile, it is desirable that it be of approximately the same size as the switch and rheostat structures heretofore employed for controlling automobile heating units. According to the invention, a rheostat switch is provided having various detailed features of structure by which reliable action is obtained, and the necessary parts for reversing and controlling the motor are compactly and effectively arranged.

For a more complete understanding of the invention, reference may be had to the following description of an embodiment thereof, and to the drawing of which: a Figure 1 is a sectional view of a switch embodying the invention.

Figure 2 is a perspective view of some of th related parts of the switch structure. V

Figure 3 is a rear end view of the switch shown in Figure 1. v Figure 4 is a section on the line 44 of Figure 1. I

Figure 5 is a section on the line 5-5 of Figure 1.

Figure 6 is a section on the line 6-6 of Figure 5. v

The switch illustrated on the drawing is housed in a casing, one part of which is a base member M of heat-resistant insulating material such as porcelain or some other ceramic material. As shown, this member is in the form of a circular disk having three shallow notches l2 in its periphery to receive fastening tongues [4 on a cup-shaped metal shell [6 which is secured to the base I!) by the tongues l4 and which cooperates with the base to enclose the switch elements.

The base member I0 is molded'to receive a number of contact elements having contact faces exposed at the inner surface of the base member. These contact elements have portions projecting through the base for connections at the outer face of the base. In order to accommodate various connecting elements required for reversing and controlling the speed of the motor, such elements are preferably arranged in two concentric circles as indicated in'Figure i. In the outer circle is an arcuate element or plate 20 the sur base member 10.

the member 16.

face of the base member l0.

face of which is flush with the inner face of the This contact element is connectible with the field coil of an electric motor 2! by means of a binding post 22 or other suitable't'erminal electrically connected with the element Why a conductor 24 extending through The binding post 22 may con- Veniently be the head of a rivet which serves-as a conductor 24 and is secured to the element 20 to hold the latter in a shallow recess in the inner Also in the outer circle are two series'of contact elements, these series being on opposite sides of a median line or diameter of the member II] which bi-Sects the element 20. Each of these series of contact elements consists of two or more elements, three being illustrated on the drawing. One-series of elements 30, 32 and 34 is to the right of the median' line of the base member as the latter is viewed in Figure 4, the other set of elements 36, 38- and 40 being to the left of the median line." The elements of both series may conveniently be flat-headed rivets, the heads being sunk flush in suitable depressions in the inner face 'of the member 18 as illustrated in Figure 2.

These rivets project through the member II] and are connected at the outer face of this member to suitable resistance coils 42 and 44 respectively.

As shown in Figure 3, the elements 30 and 3B are electrically'conected by a conductor 46 which has a terminal 48 connectible to a source of electric energy such as one of the poles of a battery.

One end of the resistance coil 42 is connected to the element 30, an end of the resistance coil 44 being connected to the element 36. The opposite end of the resistance coil 42 is connected to the element-34, the coil being connected at an intermediate point to the element 32. In like manner, the opposite end of the coil 44 is connected to the element 40 and at an intermediate point the coil is connected to the element 38. These two series of contact elements are preferably symmetrically arranged with respect to the median line hereinbefore referred to. Also symmetrical with respect to said line are a pair of contact elements 59 and 52, these elements comprising arcuate plates disposed on opposite sides "of the median line and sunk flush in the inner 'face of the base member l0. These arcuate elements lie on the inner of the two circles referred to, and are secured to suitable conductors such as rivets passing through the base member 10, the heads of; which serve as terminals 54 and 56 respectively on the outer face of the-base. These terminals are intended for connection with the disk, as shown, is provided with a pair of s1ots68 and a pair of similar slots IE! to receive upstanding ears I2 on the contact shoes 68 and 62. These ears, as indicated in Figure 1, extend away from the base member ID and project through the rotor disk 36 so that rotation of the rotor causes the shoes to slide on the face of the base l0. Each contact shoe also includes a pair of bosses l4 and I6 which bulge toward the base member I8 and are normally in direct contact therewith. The bosses, as shown in Figure 1,

are bent away from each other so that they make obtuse angles with the ears I2. The latter fit loosely in the slots 68 and I so that the shoes are rockable with respect to the disk 66, thus permitting the bosses I4 and I3 to follow any irregularities in the surface of the base member ID as the bosses move thereon. This ensures reliable operation of the shoes in making contact with the contact elements in the base Ill. The disk 66 is pressed toward the base H] by a suitable compression spring 88, the disk in turn pressing the contact shoes against the inner face of the base member I9. The shoes are each supported by the disk 66 so that the bosses I4 and I6 are radially arranged, that is, are in line with the axis of rotation of the disk, this axis passing through the center of the base member [0 and hence through the common center of the two circles in which the contact elements are arranged. Each boss I4 is spaced from its corresponding boss I5 so that the bosses I4 ride on the outer of the two circles, the bosses I6 riding on the inner circle. In Figure 5, the positions of the shoes 68 and 52 when the switch is in the off position are shown in dotted lines. As indicated, the boss I4 of the shoe 6!] then touches a portion of the face of the base member I0 between the contact elements 39 and 36 so that it is thus insula'ted from the battery terminal 48. At the same time, the shoe 62 engages the mid-point of the contact element 29, the inner boss I6 of the shoe resting between the ends of the contact elements 59 and 52. Rotation of the disk 66 to the right or to the left causes the shoes 69 and 62 to'move simultaneously in arcuate paths upon the inner face of the base member ID. Movement of the shoe 60 to the right (as in Figure 5) causes it to connect the element 58 with the ele- .of the shoe 62 into contact with the element 52,

thus connecting that element with the element 28. .This results in connecting the other brush tothe fieldcoil. Assuming that one terminal of the battery and one terminal of the field coil are .joint slots.

permanently connected or grounded, this completes the circuit through the motor, resulting in the operation of the motor at different speeds according to the amount of the resistance 42 included in the circuit.

If the shoe 68 is moved toward the left (Figure 5) and the off position, it connects the element 52 successively with the elements 36, 38 and 48, the shoe 62 engaging the element 59 to connect it to the element 29. Thus the current flows through the armature of the motor 2| in the reverse direction and results in operation of the motor in reverse, the speed of operation depending upon the amount of the resistance coil 44 which is included in the circuit.

As indicated in Figures 1 and 2, the rotor 66 is rotated by a stem which is non-round and fits in a central aperture 92 of corresponding shape in the rotor. The rear end of the stem 90 is expanded as at 93 so as to keep the rotor assembled therewith but the rotor is free to slide forward on the stem against the pressure of the spring 80. Fixed to the forward end portion of the stem 90 is a disk 94 of insulating material, this disk having a pair of nested tubular members 96 and 98 mounted on its forward face to form a socket for a lamp bulb I89. The inner socket member 98 is provided with bayonet joint slots to receive the base of the lamp bulb I90 as described in my co-pending patent application Serial No. 128,949, filed March 4, 1937. The stem 90, as described and illustrated in my said application, is hollow and contains a small spring which presses against a plunger I82 projecting from the forward end of the stem. This plunger resiliently engages the tip I84 of the lamp bulb I00, making an electrical connection therewith and holding the lamp engaged in the bayonet The disk 94 seats against a pair of shoulder elements I96 which project laterally from the stem 90. The forward end of the spring 88 also engages these elements, the rear'end of the spring 88 engaging a leaf spring I98 which in turn bears on the ears I2 of the shoe 69, so that, when the shoe is in contact with any of the elements connected to the battery terminal 48, a good electrical connection is made through the spring I08, the spring 80, and the stem 90 with the tip I94 of the lamp base. The shell of the lamp base is connected through the tubular socket member 98 to the housing shell I6, the latter being grounded.

For rotation of the disk 94, stem 99 and rotor 66, an operating member consisting of a finger knob I Illmolded onto a tubular shaft I I2 is operatively connected with the tubular member 95, the latter being secured to the disk 94 as described in my said application. Rotation of the knob III] thus causes rotation of the rotor 66. in order to provide means for ensuring that the shoe 68 Will stop in'proper positions so as to be in direct contact with some one of the elements connected to the terminal 48 when the switch is in any of its on positions, the socket member 98 is provided with a flange on which is raised a pair of bosses H4. These bosses are pressed by the spring 89 against the inner endof a sleeve I I3 which is either integral with or'permanently sepositions of the switch can be detectedby the sense of touch, such structure being described and illustrated in my said application. The

sleeve H6 is externally threaded and is provided with a pair of suitable nuts I20 and I22 by which the entire device is mounted on a supporting wall I24 such as the dashboard of an automobile, the sleeve H6 passing through a suitable hole in the supporting wall.

It is evident that various modifications and changes may be made in the embodiments of the invention herein illustrated and described without departing from the spirit or scope thereof as defined in the following claim.

I claim:

A control rheostat comprising a base of insulating material, two groups of contact elements mounted on said base and arranged in an arc of a circle, said elements being spaced from each other, resistance units connecting successive elements of each group, a terminal member on said base electrically connected to the mutually adjacent end elements of said groups, an arcuate contact element equal in length and curvature to the arc of said groups of elements and arranged diametrically opposite thereto, a second terminal electrically connected to said arcuate element, a pair of other arcuate contact elements mounted on said base in a circle concentric with the circle of first-mentioned elements but of difierent radius, the arc of each said other contact element spanning one of said groups and half of the first-mentioned arcuate element, and a pair of radially arranged bridging conductors mounted on a common diameter to revolve together about the center of said circles, each said conductor extending from one said circle to the other.

HUGH W. BATCHELLER.

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