US 2942220 A
Abstract available in
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Description (OCR text may contain errors)
June 21, 1960 H. v. ELLIOTT ET 2,942,220
CONTROL DEVICE Filed Nov. 13, 1956 44 5 a4 52 28, I Z6 INVENTORS HAROLD Vfiuorr y Joe P.6/1NADAY ATTORNEY CONTROL DEVICE Harold'V. Elliott and Joe R. Canaday, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Nov. 13, 1956, Ser. No. 621,578 6 Claims. (Cl.338172)' This invention relates to control devices and is more particularly concerned with an improved switch structure that is adapted to control the lighting circuits in an automotive vehicle.
It has been found that when rheostat control means are included in switches of the type herein contemplated, such as disclosed in application Serial No. 457,740, filed September 22, 1954, now Patent 2,779,827 which has been assigned to the assignee of the present invention, high temperatures are frequently generated in the resistance unit. These high temperatures may cause oxidation of the resistance element and deformation of certain of the switch parts particularly if the parts are formed of a super linear polyamide commonly known as nylon. Therefore, basically, the present invention is directed to eliminate the eifects of heating on the switch parts and to provide a switch structure which is easier to switch which has bails located thereon, which bails will' hold the base and housing assembled after the bails are bent over lugs in the housing.
A further object of the present invention is to actuate the various elements of a switch with a single rod that is both longitudinally and rotatively movable and has a rectilinear cross section and to prevent the rod from vibrating by a means including a bushing that is provided with a nylon insert sized to snugly engage the angular edges of the rectilinear rod. In this connection it is to be pointed out that the actuating rod is preferably triangular in cross section, which shape will provide three apexes longitudinally extending along the sides of the rod. These apexes are preferably slightly rounded to avoid cutting the nylon part, which has a bore sized to tightly engage the apexes. Further, as will be hereinafter apparent, the bore of the nylon part which is initially circular is changed inshape after the rod is positioned therein. The nylon being wear resistant and resilient will deform to receive the apexes of the rod and snugly of a single piece of metal having a center opening with a projection on one side of the opening arranged to slide upon an annular metal element and is provided with a pair of projections on the opposite side of the opening, which engage an annular resistance element. Thus, the metal part will have a three point suspension and be spaced from the annular elements so air may circulate over heat radiating and conducting means or fins which are formed on the periphery of the metal part. This will permit the heat generated in the resistance element to be dissipated. The switch is further provided with an actuating means which includes a nylon part and a rod of triangular cross section which is rotatable to actuate the nylon part.
2,342,226 Patented June 21, 1960 Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.
In the drawings:
Fig. 1 is a side view of the switch incorporating the features of the present invention.
Fig. 2 is a sectional view taken along line 2--2 in Fig. 1.
Fig. 3 is a sectional view taken along line 3--3 in Fig. 2.
Fig. 4 is a view taken along line 4-4 in Fig. 1.
Fig. 5 is a view showing in section a part of the switch along line 5--5 in Fig. 1.
In the drawings and in Fig. I particularly, the numeral designates a switch which has a switch housing 22,
' application supra.
preferably formed of a molded phenolic resin with a filler. .The housing 22 is supported by the base 24. The
base 24 and housing 22 are clearly shown and described 7 in detail in the application supra wherein it is pointed out that the housing 22 has a recess containing various switch elements which are actuated by the longitudinal movement of the actuating rod 26. Molded to the bottom surface 28 of the housing 22 are a pair of lugs 30. These lugs are located to receive suitably located openings in the base 24 to locate the base 24 and housing 22 in proper position during assembly whereby the recess in the housing is closed. Also, integrally formed on the sidewalls of the housing are four spaced lugs 32. These lugs 32 are located on the opposite sidewalls of the housing 22 along the bottom surface 28. One of these lugs is most clearly shown in Fig. 5. Extending from the periphery of the base 24 are four bails 34, which are formed as shown in Fig. 1 and located to be bent over the lugs 32, as shown in Fig. 5, for securing the housing 22 and base 24 together.
The switch 20 also includes a second switch means 36, which is actuated by the rotational movement of rod 26. ,This second switch means 36 is assembled with the switch housing 22 and base 24, as set forth in the The second switch means 36 includes a part 38, preferably formed of a dielectric material that is highly heat resistant. The part 38 is formed with a recess 39, which is generally annular in shape to receive a coiledresistor 40, which is electrically connected, as set forth in the application supra. 36 also has a central opening which is aligned. with an opening in housing 22 and the opening 42' in base 24. The opening in part 38 is preferably surrounded with a metal annulus 41, the purpose of which will become hereinafter apparent.
The switch means 36 includes a member 44, most clearly shown in Fig. 4. The member 44 is preferably formed of a single metal part to have a circular shape. This member 44 has a central opening 46, which is preferably non-circular in shape as shown. Located adjacent the opening and projecting from one surface of the member 44 is a lug or projection 48. This projection is adapted to ride on the inner annular member 41 carried in the opening in part 36. Disposed on the opposite side of the opening 46 are a pair of lugs 50 and 51. These lugs are circumferentially spaced and project from the;
acts as a rheostat element to vary the current flow in the manner well known to those skilled in the art.
The member 44 is constantly urged into contact with r the coil resistor 40 and the inner metal annulusj41 by The part I lug 56 is arranged to actuate a dome light switch, as set forth in the application supra and the lug 58 is located to engage a stop, not shown, which is formed on the base 24- to limit the rotational movement of the rod 26. The part 54 is preferably formedwith a triangularly shaped central opening 60 which receives the rod 26. The part 54 also has a projecting part 61, which is surrounded by the coiled spring52and whichhas a shape corresponding to the opening '46 in part 44 so as to provide a driving connection for the part 44 when therod 26is rotated. The part 54 is positioned between the part 44 and the turned up portion of the base 24. The end of part 54 adjacent the part 24 has an enlarged bore 62, which receives an inwardly turned threaded fiange 64 on the base 24 to maintainthe part 54 in position. Threaded into the opening in base 24, which is defined by the inwardly threaded flange 64, is a mounting and anti-rattle means which ineludes a bushing 66. This bushing has a threaded portion 68 receivable in the threaded opening 64 and a bore 69. Positioned in bore 69 is an anti-rattle means consisting of a nylon part 70. The nylon part 70 is secured in the bore 69 in any suitable manner and has a central bore 72 which is sized to tightly receive the apexes 74 of the triangular rod 26. Preferably, the bore 72 is of a size so that the nylon material of the part 72 will be slightly stretched and deformed from its normally circular shape to prevent vibration in the rod 26. The actuating rod 26 has a knob 78 secured thereto in any suitable fashion.
Manifestly, the rod 26 may be other than triangular in cross sectional shape, as shown, as for example, it may be rectangular or have any other rectilinear configuration provided the rod will have longitudinally extending apexes projecting from the surface which are in tight engagement with the nylon part. Also, the apexes 74 are preferably rounded to minimize wear of the nylon part when the rod is moved either longitudinally or rotatably.
Included on part 44 are a plurality of radially extending fins or fingers 53. These fingers are integrally formed on the part 44 and extend, as shown, so as to dissipate the heat created in the coiled resistor 40' when current passes therethrough. As heretofore stated, effect ofthe heat in the resistance 40 is detrimental to various parts of the switch and frequently causes oxidation of the coiled resistor so an improper electrical contact occurs with the member 44. Further, heat will also cause softening of the nylon parts of the switch.
The switch according to the present invention by having the fins 53 spaced from the coil 41 by the three point suspension provided by lugs 48, 50 and 51 will have an efficient heat dissipating means. Further, theuse of a rectilinear rod rather than a circular rod as a rotational driving means will cause a more positive drive even though the nylon parts are softened because of heat.
While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.
What is claimed is as follows:
1. In a device of the character described, the combination comprisingj a metal base having an opening therein, a rotatable contact member, a means for rotatingsaid contact member, a rod of rectilinear cross section extending through the opening in said base and axially slidable in said means and arranged to rotate said means when said rod is rotated, and other means for preventing said rod from rattling in said opening, said means comprising a pair of coaxial members, the outer of which is adapted to be secured in said opening and the inner of which is positioned by the outer member and has a central substantially' circular bore sized to engage the apexes only of the rectilinear rod.
2. An anti-rattle device for use in a device wherein the device has an actuating rod that is movable both longitudinally to actuate certain elements and is rotatable to actuate other elements and wherein the rod has a rectilinear cross section to provide a plurality of longitudinally extending spaced apexes about the periphery of the rod, comprising; a metal bushing having an internal bore, a
. part formed of relatively hard plastic material positioned within the bore of the bushing and having a substantially circular bore of less diameter than the largest cross sectional dimension of said rod and engaging the apexes only of said rod. I H
3. An anti-rattle device for use in a device wherein the device has an actuating rod that is movable bothlongitudinally to actuate certain elements and is rotatable to actuate other elements and wherein the rod has a triangular cross section to provide three spacedapexes about the periphery of the rod, comprising; a metal bushing having 4. An anti-rattle device for use in a device wherein the device has an actuating rod that is movable both longitudinally to actuate certain elements and is rotatable to actuate other elements and wherein the rod has a triangular cross section to provide three spaced apexes about the periphery of the rod wherein each of the apexes is provided with a rounded edge comprising; a metal bushing having an internal bore, a nylon part positioned within the bore of the bushing and having a substantially circular bore sized to engage the apexes only of said rod.
5. An anti-rattle device for use in an electric switch wherein the switch has an actuating rod that is movable both longitudinally to actuate certain switch elements and is rotatable to actuate other switch elements and wherein the rod has a rectilinear cross section to provide a plurality of spaced apexes about the periphery of the rod wherein each of the apexes is provided with a rounded edge comprising; a metal bushing having an internal bore, a part formed of relatively hard plastic material positioned within the bore of the bushing and having a substantially circular bore sized to engage the apexes only of said rod.
6. In a device of the character described, the combination comprising; a base having an opening therein, a rotatable contact member, a means for rotating said contact member, a rod of rectilinear cross section extending through the opening in said base and axially slidable said means and arranged to rotate said means when said rod is rotated, and other means for preventing s'aid rod from rattling in 'said opening, said means comprising a pair of coaxial members, the outer of which is adapted tobe secured in said opening and the inner of which is positioned by the outer member and has a central bore, said inner member being formed of plastic material and said bore having a shape defined by arcs of a circle that extend between the apexes of said rod with said apexes in engagement with said bore.
References Cited in the file of this patent UNITED STATES PATENTS 1,697,814 Forbes -2. Jan. 1, 1929 2,160,713 Bentley May 30, 1939 2,208,975 Halt July 23, 1940 2,477,746 Huddleston Aug. 2, 1949 2,479,206 Bugel Aug. 16, 1949 2,514,682 Tellkarnp July 11, 1950 2,579,841 Ludwig Dec. 25,1951 2,596,236 Glosier May 13, 1952 2,622,949 Cotchett DEC. 23, 1952 2,675,141 Schmelig Apr. 13, 1954 2,691,087 Holleran l. Oct. 5,1954 79,827 Brown et al. -2 Ian. 29, 1957 36 Barden 1 Feb. 12, 1957 9 ,1 3 Moore et al May 28, 1957