May 16 1961 H. v. ELLIOTT ETAL 2,984,804
CONTROL DEVICE Original Filed Nov. 13, 1956 2 Sheets-Sheet 1 Z0 u T 4 5% v'* Z Z I z 5 3d 5' 52 34 JNVENToRs 3? /q/oLo L/ZUOTT F 5 B JOE CHA/H047 ff P.
May 16, 1961 H. v. ELLIOTT x-:rAL 2,984,804
CONTROL DEVICE Original Filed Nov. 13, 1956 2 Sheets-Sheet 2 Fig. 7
INVENToRs Harold V Elliott By Joe R.Canaday Their A Homey United States Patent @hice CONTROL DEVICE Original application Nov. 13, 1956, Ser. No. 621,578,
now Patent No. 2,942,220, dated June 21, 1960. Di-
vided and this application Sept. 25, 1959, Ser. No.
4 Claims. (Cl. SSS- 159) 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. This is a divisional application of co pending parent application S.N. 621,578, led November 13, 1956.
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 effects of heating on the switch parts and to provide a switch structure which is easier to assemble and wherein the objectionable rattles of certain of the switch parts are eliminated.
It is an object of the present invention to provide a switch structure wherein a recess in a switch housing of molded dielectric material is closed by a base for the 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 ythe 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 lthe 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 tto 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 in shape after the rod is positioned therein. The nylon being wear resistant and resilient will deform to receive the apeXes of the rod and snugly maintain the rod from vibrating.
A still further object of the present invention is to provide a switch with a sliding contact and actuating means therefor wherein the sliding Contact is formed 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 fms which are formed on the periphery of the metal part.
Patented May 16, 1961 This will permit the heat generated in the resistance element to be dissipated. 'I'he 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.
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. l 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. l.
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. l.
Fig. 6 is an exploded view of a portion of the switch illustrated in Fig. l.
Fig. 7 is a sectional view taken along line 7-7 of Fig. 6.
In the drawings and in Fig. l particularly, the numeral 2li designates a switch which has a switch housing 22, 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 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 2S 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. l 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 2i) 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 application supra. The second switch means 36 includes a part 3S, 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 coiled resistor 40, which is electrically connected, as set forth in Patent 2,779,827 supra. The part 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 season Vsame surface of member 44 from which lug 43 projects. .The lugs 5i) and 51 are located to engage the coiled resistor 4% to complete anelectric circuit between the inner annulus 41 and the coiled resistor 4b. The coiled resistor 4t) acts as a rheostat element to vary the current iiow in the manner well known to those skilled in the art.
The member' 44 is constantly urged into contact with the coil resistor 4t) and the inner metal annulus 41 by the spring 52. When the parts of the switch are thus positioned, a threepoint suspension is provided for the member 44. The coiled spring 52 rests on a shoulder on the vpart 54 which is preferably formed of a molded material, such as a super linear polyamide, commonly known as nylon. This .part 54 has a pair of lugs 56 and 53. The lug 56 is arranged to actuate a dome light switch, as set forth in Patent 2,779,827 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 formed with a tri angularly shaped central opening 6i) which receives the rod 26. The partr54 also has a projecting part bil, which is surrounded by the coiled spring 52 and which has a shape corresponding to the opening 46 in part 44 so as to provide a driving connection for the part 44 when the rod 26 is rotated. The part 54 is positioned between the part 44 and the turned up portion of the base 2.4. The end of part 54 adjacent the part 24 has an enlarged bore 62, which receives an inwardly turned threaded ange 64 on the base Z4 to maintain the part 54 in position. Threaded into the opening in base 24, which is deiined by the inwardly -threaded flange 64, is a mounting and anti-rattle means which includes a bushing 66. This bushing has a threaded portion 68 receivable in the threaded opening 64 and a bore 69. Positioned in bore 6g 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 l72 will be slightly stretched and deformed from its normally circular shape to prevent vib-ration 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
Vmay 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.
includedon part 44 are a plurality of radially extending fins or fingers S3. These lingers Vare integrally formed on the part 44 and extend, as shown, so as to dissipate the heat created in the coiled resistor 4b when current passes therethrough. As heretofore stated, eect of the heat in the resistance 4b 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 lthe nylon parts of the switch. n
The switch according to the present invention by having the tins 53 spaced from the coil 4G by the three point suspension provided by lugs 4%, 5@ and 5l will have an eiiicient heat dissipating means. Further, the
use 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 ofthe present invention as herein disclosed constitutes a preferred form, it is to be understood thatjother forms might be adopted.
What is claimed is as follows:
V1. An electrical control device comprising, a base member, a rst insulator member formed of insulating material supported b said base member, a length of resistance material having an annular shape supported by Vsaid tirstinsulator member, an annular metal contact strip supported by said ltirst insulator member and radially spaced yfrom said length of resistance material, a bridging contactV memberformed of electrically conductive material, said contact member having first and second integral projecting portions contactinfj respectively said length off Vresistance material and said annular contact strip, said contact member further having heat radiating tin means, 4a second insulator member formed of insulating material and rotatable with respect to said base, means drivably connecting said second insulator member and said contact member whereby they rotate together, and spring means positioned between said second insulator member and said contact member for urging said contact member toward said length of resistance material and said annular contact strip.
2. An electrical control device comprising, an insulator member formed of insulating material, a length of resistance material having an annular configuration supported by said insulator member, an annular metal contact strip supported by said insulator member and spaced from said length of resistance material, a bridging contact member formed o'f electrically conductive material and having 'lirst and second integral projecting portions contacting respectively said length of resistance material and said annular contact strip, said bridging contact member having heat radiating fin means, manually operable means for rotatablyl driving said bridging contact member, and means for urging said bridging contact member toward said resistance material and said annular contact strip.
3. An electrical control device comprising, an insulator member formed of insulating material, a length of resistance material having an annular configuration supported by said insulator member, an annular metal contact strip supported by said insulator member and spaced from said length of resistance material, a bridging contact member `formed of electrically conductive material and having tiret, second and third integral projecting portions contacting respectively said length ot resistance material and said annular contact strip, said bridging contact member having heat radiating tin means, manually operable means for rotatably driving said bridging contact member, and means for urging said bridging contact `member toward said resistance material and said annular contact strip.
4. The control device according to claim 3 wherein the outer edge of the bridging co'ntact member is formed with alternate notches defining the heat radiating iin means.
References Cited in the le of this patent UNITED STATES PATENTS 633,172 Wirt Sept. i9, 1899 2,201,686 Marsten May 21, 1940 2,204,623 Ruben June 18, 1940 2,807,680 Brown et al. Sept. 24. 1957