Multi-directional switch with elastomeric pivot and sealing member

Abstract

An improved multi-directional switch is disclosed having an elastomeric member serving both a sealing and a resilient function thereby simplifying the structure and construction of the switch. The subject switch comprises a housing having a plurality of fixed contacts disposed therein in spaced relationship. A switch actuation shaft is mounted through a housing face plate by an elastomeric pivot and seal member. The face plate and shaft assembly are mounted on the housing so that the inner end of the shaft can be moved selectively into contact with the fixed contacts. One of the fixed contacts serves as a common and also makes contact with the shaft.

Description

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates to a multi-directional switch and in particular to a multi-directional switch having an actuation shaft which is self biased to a predetermined position and mounted in the switch housing by a fluid tight seal.

2. The Prior Art

There are many instances when it is desirable to have a single switch with the capability of providing multiple functions. A common example of a use for such a switch would be the drive system used to adjust the driver's seat of an automobile where motors are used for raising and lowering the seat as well as moving it forwardly and rearwardly. Most of the known multi-directional switches are extremely complex structurally. Many of them require a system of gimbles or a plurality of contact pairs which are cammed into engagement by movement of a switch handle. An example of this type of switch can be found in U.S. Pat. No. 2,808,476. The multi-directional switches employing a ball pivot all require some sort of spring arrangement as can be seen from U.S. Pat. Nos. 1,426,193; 1,434,217; 1,510,068; 2,521,489; and 2,793,259. Most of these known switches, because of their structural configuration, are quite difficult to make fluid tight and thus require an additional sealing cover which is difficult to install and wears out rapidly.

SUMMARY OF THE INVENTION

The subject multi-directional switch includes a housing having one end open to receive therein a face plate provided with a central orifice. A switch actuation handle or shaft is mounted in the orifice by means of an elastomeric pivot and seal member and a contact plate is fixed on the inner end of the shaft. A plurality of fixed contacts are disposed within housing with one contact serving as a common contact. The elastomeric member both seals the shaft in the switch housing and biases the shaft and contact plate to a predetermined position in engagement with the common contact. A program disc is mounted in the housing with the shaft extending through a profiled aperture therein so that the aperture restrains or restricts the movement of the shaft to positions which will allow it to bring the contact plate into engagement with at least one of the fixed contacts while maintaining contact with the common contact. It is also possible to have omni-directional operation by omitting the program disc.

It is therefore an object of the present invention to produce a multi-directional switch in which the switch actuation shaft is mounted in the switch housing by a fluid tight sealing and biasing member.

It is another object of the present invention to produce a multi-directional switch which is extremely simple in structure and yet is fluid tight.

It is still another object of the present invention to produce an omni-directional switch having an actuation member biased to a normal position and mounted in the switch housing in a fluid tight manner by an elastomeric member.

It is yet another object of the present invention to provide a multi-directional switch having a plurality of fixed contacts disposed about the interior of a housing with a switch actuation shaft or handle mounted through a face plate of the housing by means of an elastomeric member serving both as a fluid tight seal and to bias a contact plate on the free end of the shaft or handle into engagement with a common contact.

It is a further object of the present invention to produce an improved multi-directional switch wherein the movement required to engage contacts is determined by shaft length, contact spacing and contact plate size.

It is a still further object of the present invention to produce a multi-directional switch which is a momentary action switch biased by an elastomeric sealing member to a predetermined position.

It is a still further object of the present invention to produce a multi-directional switch which is biased to a normal position but which can be locked in any contacting position.

It is another object of the present invention to mount the actuating member of a multi-directional switch in a housing by means of an elastomeric member which biases the actuating member to a normal position and forms a fluid tight seal during all movements of the actuating member.

It is still another object of the present invention to produce an improved fluid tight multi-directional switch which can be readily and economically manufactured.

The means for accomplishing the foregoing objects and other advantages of the present invention will become apparent from the following detailed description taken with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a multi-directional switch including the subject invention therein;

FIG. 2 is a longitudinal section through the switch of FIG. 1;

FIG. 3 is a plan view of an alternate embodiment of the program disc;

FIG. 4 is a plan view of another alternate embodiment of the program disc; and

FIG. 5 is a side elevation of the subject switch mounted in a panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The subject multi-directional switch 10 includes a first housing member 12 which is open on one end and closed at the opposite end by plate 14. A plurality of contact mounting apertures 16, 18 are formed in plate 14. A second housing member 20 includes a face plate 22 having a central aperture 24 and a sleeve 26 depending from the face plate and adapted to be received within the open end of the first housing member 12. A plurality of projections 28 depend from the free end of the sleeve 26.

A substantially cylindrical plug 30 of elastomeric material having an unstressed outer diameter greater than aperture 24 is used to mount a switch actuation shaft 32 in the aperture 24. The shaft 32 can be made of either metal or insulating material and is preferably provided with a gripping portion 34, here shown as a portion of a lesser diameter than the remainder of the shaft. The gripping portion 34 is substantially centered within the elastomeric member 30 and in the aperture 24 and serves to prevent relative axial movement of the shaft in member 30. The gripping portion could also be enlarged or roughened, for example. A hand grip 36 of insulating material is fixed to the outer end of the shaft 32 while a metallic contact plate 38 is fixed to the inner end 40 of the shaft.

When the switch is to function as a multi-directional switch, program disc 42 is mounted in the housing 12. The disc has a profiled central aperture 44 and first and second pluralities of notches 46, 48, respectively, disposed about the periphery thereof. The shaft 32 passes through the aperture 44 while projections 28 of housing member 20 engage in the respective first notches 46.

The contacts fixed in the housing include a common contact 50 and fixed outer contacts 52, 54, 56, 58. The common contact 50 is shown with a blade shaped mounting portion 60 and a semi-spherical head 62. The other contacts each have a similar blade shaped mounting portion 64 on one end and a mounting tab 66 on the opposite end. The contacts are mounted in the housing 12 with the blades 60, 64 extending through the apertures 16, 18, respectively. The tabs 56 of the outer fixed contacts engage in respective ones of the second notches 48 in the program plate 42, and are thereby held against the inner walls of the housing member 12. It is to be understood that the means disclosed for mounting the fixed contacts is merely illustrative of one acceptable type. Other contact configurations, including different numbers and positioning of contacts can be employed without departing from the scope of the present invention.

A switch according to the present invention is assembled by first passing the blades of the contacts 50, 52, 54, 56, 58 through the respective apertures 16, 18 of plate 14. The program disc is inserted into the housing with the tips 66 of the contacts engaging in respective notches 48. The shaft 32 is driven through the elastomeric sealing member 30 and the shaft-sealing plug assembly is inserted through the central aperture 24 of the face plate 22. The contact plate 38 is fixed on the free end 40 of the shaft and the insulated hand grip 36 is fixed on the opposite end of the shaft. The second housing member 20 is fitted into the open end of housing member 12 with the projections 28 extending into steps 46 to thereby lock the program disc in position.

It will be seen, from FIG. 2, that the elastomeric member 30 serves as both a pivot and seal for the shaft 32. The elastomeric member normally biases the shaft to a position substantially aligned with the axis of the housing and with the contact plate 38 engaged against the common contact 50. When the shaft is moved in one of the contact engaging directions, the elastomeric member serves as a resilient pivot allowing the movement of the handle yet maintaining a longitudinal bias on the shaft so that the contact plate 38 will remain in engagement with the common pin 50 while the outer periphery of the contact plate 38 engages with one or more of the fixed contacts 56. Likewise the return movement of the shaft to the normal position will be accomplished by the resilient action of the elastomeric member.

In a multi-directional switch embodiment, the movement of the shaft is restricted in direction by the profiled aperture 44 in the program disc 42. The illustrated disc is for a quad contact embodiment with the central aperture 44 having a four lobed configuration with each lobe aligned with a respective one of the four contacts 52, 54, 56, 58. Clearly the subject switch need not be limited to either four contacts or this particular lobed configuration. It is also foreseen that, when situations demand, the lobes of the aperture 44 could be so arranged that the contact plate 38 can engage one or more of the fixed contacts 56 as illustrated in FIG. 3. Also the individual lobes can be provided with a locking configuration, for example a hook shape similar to that shown in FIG. 4, to lock the shaft in a particular contact engaging position.

An omni-directional embodiment of the subject switch can be constructed by omitting the programming disc 42 and replacing the plurality of fixed contacts 52, 54, 56, 58 with a single annular contact (not shown). In this embodiment the plate 38 will engage the annular contact regardless of the direction of movement of the shaft. Such a switch would be particularly useful as an emergency shut off switch, when it is desirable to have a function performed in haste, or for a patent call switch when movement is hampered but the need for assistance is great.

The present embodiment has been described with only a pivoting movement of the shaft 32 in the sealing plug 30. Since the plug is resilient, it would also be possible to have the shaft rotate about its own axis or be moved axially to accomplish engagement of contacts or locking in a particular position. The contact plate 38 will, of course, have to be modified in accordance with the type of motion selected. Regardless of the type of movement, the shaft will be biased toward its normal position and a fluid tight seal with the housing member 20 will be maintained.

It is also foreseen that the subject switch can be provided with mounting flanges 68, as shown in FIG. 2, snap rings 70, as shown in FIG. 5, or other well known switch mounting means. Also well known interengaging locking devices such as detents and projections 72 can be provided between the second housing member 20 and the housing 12 to insure the tight assembly and mounting thereof. Such means are conventional and therefore need not be discussed in any detail.

The present invention may be subjected to many modifications and changes without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as merely illustrative and not restrictive of the scope of the invention.

Claims

What is claimed is:

1. A multi-directional switch comprising:

a housing member having one open end,

a face plate member fitted to the open end of said housing and having a central aperture therein,

at least two contacts fixed in said housing with one of said contacts being a common contact and the remaining contacts disposed about the inner surface of said housing, and

an actuating assembly comprising a shaft, an elastomeric member and a contact plate, said shaft being mounted passing through said elastomeric member which in turn is mounted in said aperture of said face plate member forming a fluid tight seal therewith, said elastomeric member resiliently biasing said shaft to a normal position with respect to said face plate member, said contact plate fixed on the inner free end of said shaft, whereby movement of said shaft from said normal position causes said contact plate to engage said common contact and at least one other contact.

2. A multi-directional switch according to claim 1 further comprising:

a program disc having a profiled central aperture, said disc being mounted within said housing with said shaft passing through said central aperture, said aperture defining paths to restrict movement of said shaft to assure said contact plate will engage only selected contacts.

3. A multi-directional switch according to claim 1 wherein said shaft includes:

a gripping portion which is substantially centered in said elastomeric member and said aperture in said face member to assure proper fixed positioning of said shaft.

4. A multi-directional switch according to claim 3 wherein said gripping portion comprises:

a portion of said shaft having a lesser diameter than the remainder of said shaft.

5. A multi-directional switch according to claim 3 wherein said gripping portion comprises:

a portion of said shaft having a greater diameter than the remainder of said shaft.

6. A multi-directional switch according to claim 3 wherein said gripping portion comprises:

a roughened surface area on said shaft.

7. A multi-directional switch according to claim 3 wherein said gripping portion comprises:

a profiled section on said shaft.

8. A multi-directional switch according to claim 1 wherein said shaft is formed of insulating material.

9. A multi-directional switch according to claim 1 wherein said shaft is metal.

10. A multi-directional switch according to claim 9 further comprising an insulative hand grip on the outer free end of said shaft.

11. A multi-directional switch according to claim 1 wherein said movement of said shaft is a pivotal movement about said elastomeric member.

12. A multi-directional switch according to claim 1 wherein said movement of said shaft is rotary about the axis of said shaft creating torsion in said elastomeric member.

13. A multi-directional switch according to claim 1 wherein said movement of said shaft is along its longitudinal axis.

14. A multi-directional switch according to claim 2 wherein said program disc includes means for locking said shaft in a contact engaging position.

15. A multi-directional switch according to claim 2 wherein said profiled central aperture allows said contact plate to engage more than one contact.

16. A multi-directional switch according to claim 1 further comprising means for securing said face plate member in said housing.

17. A multi-directional switch according to claim 1 further comprising means for mounting said switch in an associated panel.

18. A multi-directional switch according to claim 1 wherein said housing member and said face plate member are formed of insulative material.

19. A multi-directional switch according to claim 1 wherein said common contact is mounted in substantial axial alignment with said shaft and the remaining contacts are mounted thereabout in an annular configuration.

20. An omni-directional switch comprising:

a housing having one open end,

a face plate member fitted to the open end of said housing and having a central aperture therein,

an annular contact fixed in said housing, a common contact fixed in said housing within said annular contact, and

an actuating assembly comprising a shaft, an elastomeric member and a contact plate, said shaft being mounted passing through said elastomeric member which in turn is mounted in said aperture of said face plate member to form a fluid tight seal therewith, and to bias said shaft to a normal position with respect to said face plate member, said contact plate fixed on the inner free end of said shaft whereby movement of said shaft causes said plate to engage said common contact and said annular contact.