US3732388A

US3732388A - Unitary insulating housing for rocker switches

Info

Publication number: US3732388A
Application number: US00166042A
Authority: US
Inventors: W Taylor
Original assignee: TURNOCK G Ltd
Current assignee: TURNOCK G Ltd
Priority date: 1970-07-29
Filing date: 1971-07-26
Publication date: 1973-05-08
Anticipated expiration: 1990-05-08
Also published as: DE2137336A1; GB1332657A

Abstract

A rocker switch has a rocker housing and a cylindrical switch housing extending from the rocker housing. A switch mechanism is mounted in the switch housing and is operated by a rocker mounted at least partially within the rocker housing to pivot about an axis. The cylindrical switch housing is smaller than the rocker housing so that the switch housing can be inserted in a hole in a face to project through the hole and be located with the rocker housing abutting the face. Also the two housings are formed as integral parts of a switch body comprising a pair of moulded shells arranged on opposite sides of a plane including the axis of the cylindrical switch housing.

Description

C Umted States Patent 1191 [111 3,732,388

Taylor 1 May 8, 1973 54] UNITARY INSULATING HOUSING FOR 3,548,131 12 1970 Piber ..200/168 c ROCKER SWITCHES 3,538,285 11/1970 Orts ...200/l72 A X 2,847,559 8/1958 Harrin ton et a1 ..200/l67 A x [751 Invenm" Wlllm" Eric l walsall 2,430,189 11 1947 Schelh1an ..200/l67 A x gland [73] Assignee: George Turnock Limited and Henry Examiner-PI- Jones Charles Shem), London, England Attorney-Scrivener, Parker, Scrivener & Clarke [21] App! 166342 A'rocker switch has a rocker housing and a cylindrical switch housing extending from the rocker housing. A v [30] Foreign Application P i rit D t switch mechanism is mounted in the switch housing and is operated by a rocker mounted at least partially July 29, 1970 Great Brltam ..36,60l/70 within the rocker housing to pivot about an axis. The cylindrical switch housing is smaller than the rocker 12%] (gl. ..200/l68 C, housing so that the Switch housing can be inserted in a d A 67 A hole in a face to project through the hole and be 1 8 located with the rocker housin abuttin the face.

Also the two housings are formed as integral parts of a switch body comprising a pair of moulded shells ar- [56] References Cited ranged on opposite sides of a plane including the axis UNITED STATES PATENTS of the cylindrical switch housing.

3,412,225 11/1968 Rogers ct al. ..200/168 C 9 Claims, 4 Drawing Figures PATENTEBHAY 13 SHEET 2 F 2 4 4 III,

28 27/ 3032 33 34 15 Maw 38 UNITARY INSULATING HOUSING FOR ROCKER hole, abuts said one side of the panel, means being provided to secure the switch in this position.

Hitherto the usual kind of rocker switch has had the switch mechanism and the rocker mounted in a common casing of substantially rectangular shape as viewed when facing the rocker, there being an outwardly directed flange around the front part of the casing. To mount a switch of this kind on a panel it has been practice to form a rectangular hole in the panel and to push the casing through the hole from one side "until the flange abuts the panel. The advantage of the present invention is that the switch can be mounted in a relatively small circular hole in a panel, and that the size of this hole is not governed by the size of the rocker. Further, it is in general less expensive to make a circular hole than to make a rectangular hole. Thus it is possible to make a rocker switch which can be mounted in a hole A an inch in diameter while having a rocker threequarters of an inch or even greater in length. Rocker switches of this kind are particularly suitable for use for controlling accessories in motor vehicles, for it is customary to provide panels for supporting the switches for such accessories. Hitherto it has not been possible to use rocker switches on such panels, and it has been necessary to use toggle switches.

There will now be described, by way of example, one particular form of switch embodying the invention and primarily intended for use in motor vehicles. This switch is illustrated in the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of the switch components,

FIG. 2 is a perspective view of an assembled switch in relation to a support panel,

FIG. 3 is a section through the switch in the off position, and

FIG. 4 is a section through the switch in the on position.

In the drawings the switch has a body made as a moulding of a suitable plastics material such as that sold under the Registered Trade Mark Delrin. The body includes a rear portion or switch housing 1 which is of tubular shape and which is open at one end and closed at the other end by an integral end plate 2. The body also includes a front portion which constitutes a rocker housing 3 and which has a rectangular back plate 4, with a central circular hole leading directly into the interior of the switch housing 1, and with a forwardly directed peripheral flange 5. That part of the switch housing 1 adjacent to the back plate 4 of the rocker housing 3 is externally screw-threaded and can engage a nut 6 passed over the remainder of the switch housing. The maximum diameter of the switch housing 1 is slightly less than half an inch. In use the switch housing is passed through a half inch diameter hole 7 in a relatively thin panel 8, and the nut 6 is passed over the housing and brought into engagement with the screw-threaded part thereof. When the nut 6 is tightened that part of the panel 8 bordering the hole 7 is trapped between the nut 6 and the back plate 4 of the rocker housing 3.

As shown in FIG. 1 the switch body is assembled from two components, or shells 9, which abut each other and which lie on opposite sides of a central plane which includes the axis of the tubular switch housing 1 and is parallel with the shorter sides of the peripheral flange 5 of the rocker housing 3. Each shell 9 thus comprises a semi-cylindrical portion with a hollow box-like portion 11 at one end. The shells are moulded so that they lie on the same side of said central plane and with their semi-cylindrical portions co-axial. The end plates 2 of those portions face one another and are joined by an integrally formed strap 10. The central part of the strap 10 is weakened so that it can readily be folded in two during assembly. The strap 10 may be severed from the body after assembly or may remain as a U-shaped component projecting from the end plate as shown in FIGS. 3 and 4. Alternatively the shells 9 may be moulded separately.

The shells 9 are held together by a rectangular collar 12 or bezel which is fitted around the peripheral flange 5 of the rocker housing 3. The collar 12 is preferably formed from the same material as that used for the shells 9, and it may have a film of metal deposited on it by a vacuum process to give it a metallic appearance. The collar 12 has an intumed flange 13 at the front which conseals the front edges of the peripheral flange 5. The collar 12 is preferably retained by friction alone but may be arranged to snap onto the flange 5, a part of it passing behind the back plate or entering recesses in the outer face of the flange. Alternatively the shells 9 may be adhesively secured together.

A boss 14 of approximately square cross-section projects from each of the semi-circular end plates 2 of the semi-cylindrical portions of the switch housing 1, the bosses l4 abutting each other when the switch is assembled. One boss 14 carries an integral pin 15 while the other boss is formed with a complementary through hole 16. During assembly the pin 15 is pushed through the holes 16 and its projecting end is cold-riveted to hold the bosses 14 together.

A rocker 17 is a close fit within the peripheral flange 5 of the rocker housing 3 though one end or the other projects from the housing when it is in either of its end positions. The front face of the rocker 17 is slightly concave, and the ends of the rocker 17 are slightly convex. The rocker 17 is moulded from transparent or translucent material and contains a bulb 18 which is arranged to light when the switch is turned on. The bulb 18 has an Edison screw cap 19 of about 3/16 of an inch in diameter. The rocker 17 is hollow and opens towards the back plate 4 of the rocker housing 3. The bulb 18 is housed in a carrier 20, formed from an appropriate plastics material, which fits into the central part of the interior of the rocker 17. The carrier 20 is in the shape of a rectangular block formed with an open-ended channel in which the cap 19 of the bulb 18 rests. Trunnions 21 project outwards from the block, their common axis being normal to the length of the channel, and

the sides of the rocker 17 are formed with semi-circular slots 22 which receive the inner portions of the trunnions 21. Outer portions of the trunnions 21 enter aligned recesses 22 in the peripheral flange 5. The recesses 22 extend on both sides of the central plane and can thus be readily moulded in the two shells 9. Further the trunnions 21 can be introduced into the recesses during assembly of the shells 9. The arrangement is such that the rocker 17 can rock through 30, further movement being prevented by the ends of of the rocker l7 abutting the back plate 4 of the housing 3. A metal blade 24 projects through a slot in the carrier 20, the inner end engaging the cap 19 of the bulb 18 at the base of the channel, and the outer part forming an operating cam. The blade 24 may be formed from brass but it is preferably formed from steel as the wearing properties of steel are better than those of brass.

The end contact 25 of the bulb 18 is in permanent contact with the strip-metal contact band 26 housed in the adjacent end of the rocker. The contact band 26 is larged U-shaped, one limb engaging the contact 25, the base abutting the face of the rockers interior which faces the back plate of the rocker housing, and the other limb abutting the end wall of the rocker and terminating in a contact portion which extends over the adjacent edge of the end wall of the rocker, in a shallow recess in that wall. During assembly the contact band 26 is pushed into the appropriate end of the interior of the rocker 17 where it may be held by friction or being snapped beneath lugs on the side wall of the rocker, or by stops cold-riveted over the margins of the contact after the latter is in position.

The blade cam 24 projects rearwards from the rocker. The rear end of the cam 24 projects into the switch housing 1 through an open end thereof and is tapered in two stages to terminate at an edge- 27. Those parts 28 of the cam 24 having the first stage of the taper are such that when the rocker 17 is in either of its end positions one of these parts 28 of the cam abutsthe inside of the switch housing 1 of the body. Those parts 29 of the cam 24 having the second stage of the taper engage the central part of a cylindrical metal roller 30 which constitutes the contact member of the switch.

The axis of the contact member 30 is at right angles to the axis of the tubular switch housing 1, and the contact member extends through aligned slots in parallel arms 31 of a locator 32 which also includes a body uniting the arms and a spigot 33 which extends rearwards from the body down the switch of the locator32, and one end of the spring 34 abuts the body of the locator 32 while the other end of the spring 34 abuts the end plate 2 of the switch body.

When the switch is in its ofi position (FIG. 3) the locator 32 abuts one side of the switch housing 1, while the cam 24 abuts the opposite side thereof. The cam 24 also engages the contact member 30 between the arms 31 of the locator 32. If the rocker 17 is then moved to its other position (FIG. 4) the cam 24 first moves the contact member 30 towards the rear of the switch against the action of the spring 34; then, when the rear edge 27 of the cam 24 passes the center-line of the contact member 30, this member is moved by the spring 34 towards the other side of the switch housing 1. This movement of the contact member 30 terminates when the contact member 30 engages two spaced parallel contact plates 35 disposed immediately outside the arms 31 of the locator 32.

Tha main planes of the contact plates 35 are parallel with each other and with the axis of the switch'housing 1 and are at right angles to the axis of the contact member 30. Each contact plate 35 includes a parallelsided strip abutting the side of the switch housing and terminating at its forward end in a stop 36 which projects towards the opposite side of the housing. The edge of the stop 36 is in the shape of a 90 concave arc, and the arrangement is such that the spring 34 urges the contact member 30 onto the stops 36 when the switch is in its on position. Thus there is relatively extensive contact between the contact member 30 and the contact plates 35 when the switch is on. The extent of the contact may increase with use as the contact member 30 beds into the stops 36.

When the rocker 17 is rocked from the on position to the off position the part 29 of the cam with the second stage taper engages the contact member 30 and initially moves it towards the rear of the switch against the action of the spring 34; then, when the rear edge 27 of the cam 24 passes the center-line of the contact member 30, this member is moved by the spring 34 to the off position. During the rearward movement of the contact member 30 the member may roll in the locator 32, or it may rub against the contact plates 35 or may do both. In each instance, however, there is a tendency for the contacting surfaces either to be replaced by fresh ones or to be cleaned. The actual movement of the contact member 30 depends on a large extent on the size of the slots in the arms 31 of the locator 32, and these may be such as to permit free rotation of the member 30, restricted rotation, or no rotation at all.

In an alternative arrangement the arms 31 of the locator 32 are formed with holes rather than slots to receive the contact member 30.

The contact plates 35 extend through parallel slots 37 in the end plate 2 of the switch housing 1, pass on opposite sides of the bosses 14 and terminate in pierced terminal blades 38 suitable for snap engagement .with complementary connectors of the well-known kind. One half of each of the slots 37 in the end plateis formed in one shell 9, while the other half is formed in the other shell 9. The contact plates 35 are introduced into the slots 37 during assembly of the shells 9, and the plates 35 and shells 9 are so shaped than when the moving body is assembled the plates are prevented from moving relatively to the body.

When the switch is in its on position the contact portion 26 engages one end of a conductive strip 39 mounted on the body of the switch, but when the switch is in its off position the contact portion 26 is separated from the conductive strip 39. One end part of the conductive strip lies against the front surface of the back plate 4 of the rocker housing 3, extending from one end of that surface to a position adjacent to the switch housing 1. The strip 39 then passes a slot 40 in the back plate 4 and extends along the outer surface of the switch housing 1 towards the end plate 2 thereof. The outer surface of the switch housing 1 is formed with a shallow rectangular groove 41 which can receive that part of the conductive strip 39. In its normal, unstressed state that part of the strip 39 alongside the switch housing 1 is bowed outwards so that-only its ends are located in the groove 41. When the switch is mounted in its position of use, however, the strip 34 is at least partially flattened into the groove is shown in FIGS. 3 and 4 and engages the metal panel 8 through which the switch housing extends, or the securing nut 6, or some other adjacent electrically conductive part. If by any chance the panel 8 is made of a non-conductive material the strip 39 may contact a metal ring (not shown) disposed on the switch housing 1 immediately behind the panel 8. The hole in the ring may conveniently be of the same diameter as that in the panel.

The ring is formed with three outwardly directed integral fingers closely adjacent to one another, the central one being bent somewhat from the plane of the ring and of the outer fingers. In use a earthing wire can be passed between the center and outer fingers and the fingers can be turned over, crimped or otherwise deformed to trap the wire in place and make good electrical contact with it.

Each shell 9 is formed with an outwardly directed integral fin (not shown) lying substantially in the plane along which the shells abut each other, the fins extending on opposite sides of the switch housing 1. Each fin extends from a position adjacent to the end plate 2 of the switch housing 1 to a position adjacent to the screw-thread on the switch housing 1. Each fin extends outwards to an extent substantially equal to the maximum diameter of the screw-thread. In manufacture the retaining nut 6 is pushed onto the unthreaded rear portion of the switch housing 1 and is frictionally held in place by the fins. It may also serve to retain in place a ring of the kind described in the last preceding paragraph. It is intended that the person installing the switch should pull the nut 6 from the housing ll, and the ring if such is present, and then pass the housing 1 through the hole 7 in a mounting panel 8 or the like, replace the ring, if any, and replace and screw up the nut 7 to hold the switch in place. Use of the fins avoids the need for the manufacturer to screw the nut 6 onto the switch housing during assembly and for the person installing the switch to unscrew it again before mounting the switch in position. If desired the fins may be tapered towards the nut to be pushed readily onto the fins. The use of fins, or like resilient components, in this manner is not restricted to switches embodying the invention but is of general application.

In order to ensure that the end of the strip 39 inside the rocker housing 3 does not move when the outer end part of the strip is flattened, the inner end portion is anchored. There may be parallel ribs projecting from the back plate and defining between them a slot for receiving the strip 39; parts of the ribs near the switch housing may be deformed after the strip 39 is in place so as to overlap the margins of the strip 399 and thus anchor it in place.

When the switch is in use in a motor vehicle it may be used for operating an accessory such as a spot-light. In this case one of the contact plates 35 is connected to the live terminal of the battery and the other is connected by way of the accessory to earth. The conductive strip 39 which extends outside the switch is also earthed. When the switch is in its on position the contact member 30 engages both ofthe contact plates 35 thus enabling current to pass through the accessory. At the same time current flows from the live contact member 30 to the cap 19 of the bulb 18, while the end contact 23 of the bulb is earthed through the U-shaped contact band 26 and the external conductive strip 39. The bulb 18 is thus lit when the accessory is operative.

In an alternative form of switch (not illustrated) the body is made as a unitary moulding in a simple two-part mould, the parts separating in a direction parallel with the axis of the switch housing 1. One part of the mould defines the outside of the body, and includes portions which define the slots 37 in the end plate 2 of the housing 1 to receive the contact plates 35. Other portions of this part of the mould extend through the back plate4 of the rocker housing 3 so as to define the recesses 23 for engagement by the rocker trunnions 21. These latter portions may break into the thread on the outside of the switch housing 1.

The rocker 17 is also slightly modified. The end faces of the trunnions 21 are inclined so that during assembly the rocker 17 can be pushed into the rocker housing 3, and the inclined faces can progressively urge the opposite sides of the peripheral flange 5 apart until the trunnions 21 become aligned with the recesses 23 whereupon the sides of the flange 5 snap inwards to retain the rocker 17 in position.

The side edges of the contact plate 35 are stepped inwards towards the rear and engage shoulders on the housing which prevent undesired rearward movement of the plates. During assembly of the switch the blades 38 of the contact plate 35 are pushed through the slots 37 from the interior of the switch housing 1. In order to retain them in position each plate 35 is formed with a circular hole, a little in front of the end plate 2 of the switch housing 1. An associated lug on the housing snaps into each hole but is rather less long than the thickness of the plate. The inner faces of the lugs may be tapered to assist the passage of the plates but to prevent their withdrawal. In an alternative method of retaining the contact plate 35 in position the holes in the plates are replaced by saw-tooth-shaped notches in the edges of the plates, a little in front of the end plate of the switch housing, while the lugs are replaced by complementary saw-tooth-shaped projections in the switch housing. These permit insertion of the plates but prevent their withdrawal.

Another embodiment of the switch is not iluminated, the operating cam 24 and trunnions 21 being moulded integrally with the rocker 17.

The switch mechanism described in the foregoing description is of the kind which is also described in British Patent No. 1,193,072 of George Turnock Limited and Henry Charles Shelton.

I claim:

1. A rocker switch comprising a rocker housing, a cylindrical switch housing extending from said rocker housing, the external diameter of said cylindrical switch housing being less than any outside dimension of said rocker housing in a plane normal to the axis of said cylindrical-switch housing, switch mechanism housed in said cylindrical switch housing, and a rocker mounted at least partially within said rocker housing and manually operable to operate said switch mechanism, and wherein said cylindrical switch housing and said rocker housing are formed as integral parts of a switch body comprising a first moulded shell and a second moulded shell, said shells lying principally on opposite sides of a plane including the axis of said cylindrical switch housing.

2. A rocker switch in accordance with claim 1 wherein a first portion of one shell adjacent to said plane including the axis of said cylindrical switch hous- 'ing is formed with a recess extending from said plane, a

second portion of said one shell adjacent to said plane and disposed opposite said first portion is formed with a recess extending from said plane, and in the assembled switch body said recesses are closed by portions of the other said shell to define a pair of opposed orifices in said rocker housing, trunnions forming pivots for said rocker being journalled in said orifices.

3. A rocker switch in accordance with claim 2 wherein said orifices extend into the other of said shells.

4. A rocker switch in accordance with claim 1 including a strap moulded integrally with said shells, said shells being moulded as a matched pair connected endto-end by said strap.

5. A rocker switch in accordance with claim 1 wherein at least a portion of said cylindrical switch housing is externally screw-threaded.

6. A rocker switch in accordance with claim 5 wherein said cylindrical switch housing is provided with a first outwardly directed fin and a second outwardly directed fin in a position diametrically opposed to said first fin, said fins extending substantially to the maximum diameter of the screw-thread along an unthreaded portion of said switch housing.

7. A rocker switch in accordance with claim 1 wherein said rocker is at least translucent, a lamp is mounted in said rocker and means are provided operative to light said lamp when said rocker is in one position.

8. A rocker switch in accordance with claim 4 wherein said lamp comprises a bulb having an end contact and a shell contact, a bulb carrier, a fixed contact located on said switch body, a contact band having a portion in contact with said end contact of said bulb and a portion operative to contact said fixed contact when said rocker is in said one position, and a contact member carried by said bulb carrier and abutting said shell contact of said bulb, said contact member also forming an operating cam of said switch mechanism.

9. A rocker switch in accordance with claim 1 wherein a hole is formed in one of said shells and a pin is provided on the other of said shells, said pin projecting into said hole to locate said shells relative to each other.

Claims

1. A rocker switch comprising a rocker housing, a cylindrical switch housing extending from said rocker housing, the external diameter of said cylindrical switch housing being less than any outside dimension of said rocker housing in a plane normal to the axis of said cylindrical switch housing, switch mechanism housed in said cylindrical switch housing, and a rocker mounted at least partially within said rocker housing and manually operable to operate said switch mechanism, and wherein said cylindrical switch housing and said rocker housing are formed as integral parts of a switch body comprising a first moulded shell and a second moulded shell, said shells lying principally on opposite sides of a plane including the axis of said cylindrical switch housing.

2. A rocker switch in accordance with claim 1 wherein a first portion of one shell adjacent to said plane including the axis of said cylindrical switch housing is formed with a recess extending from said plane, a second portion of said one shell adjacent to said plane and disposed opposite said first portion is formed with a recess extending from said plane, and in the assembled switch body said recesses are closed by portions of the other said shell to define a pair of opposed orifices in said rocker housing, trunnions forming pivots for said rocker being journalled in said orifices.

4. A rocker switch in accordance with claim 1 including a strap moulded integrally with said shells, said shells being moulded as a matched pair connected end-to-end by said strap.