US3277739A - Rotary switch cap seal - Google Patents

Description

Oct. 11, 1966 M. MORSE 3,277,739

ROTARY SWITCH CAP SEAL Filed May 15, 1964 United States Patent 3,277,739 ROTARY SWITCH CAI SEAL Milton Morse, 1 Horizon Road, Fort Lee, NJ. Filed May 15, 1964, Ser. No. 367,680 1 Claim. (Cl. 74558.5)

This invention relates generally to the field of rotary hermetic seals, and more particularly to an improved form thereof especially adapted to effect a seal about an operating button as the same projects outwardly from an opening in a plate or other planar surface. Devices of this general type are known in the art, and the invention lies in specific constructional details permitting the seal to be maintained as the device is moved with respect to the outer surface with which it makes a seal.

It is among the principal objects of the present invention to provide an improved seal of the class described which may be conveniently and economically molded as a single injection of elastomeric material such as silicon rubber or the like.

Another object of the invention lies in the provision of an improved sealing device including an inwardly flared sealing flange or lip which resiliently and slidably contacts the surface with which the seal is made, whereby the switch disposed therebeneath may be rotated to make and break contact without disturbing the sealing action.

Yet another object of the invention lies in the provision of an improved seal of the class described in which the cost of fabrication may be of a reasonably low order, with consequent wide sale, distribution and use.

Yet a further object of the invention lies in the provision of an improved sealing device of the class described which may be conveniently installed and removed without the use of special tools, and by those possessing only ordinary skill, and which will not be readily accidentally removed or disturbed to a condition in which the sealing action will be lost.

A feature of the invention lies in the fact that the device, in addition to providing a sealing action, provides an improved grip for the fingers of the user in operating the switch disposed therebeneath.

Another feature of the invention lies in the attractive external appearance of the same.

These objects and features, as well as other incidental ends and advantages, will more fully appear in the progress of the following disclosure, and be pointed out in the appended claim.

In the drawing, to which reference will be made in the specification, similar reference characters have been employed to designate corresponding parts throughout the several views.

FIGURE 1 is a plan view of an embodiment of the invention.

FIGURE 2 is a central longitudinal sectional view of the embodiment showing the same in installed condition upon a conventional rotary switch.

FIGURE 3 is a bottom plan view of the embodiment.

FIGURE 4 is a side elevational view thereof.

In accordance with the invention, the device is illustrated in FIGURE 2 in the drawing in operative connection with a rotary switch 11 of a type including a rounded button 12 beneath which switch contacts (not shown) are disposed. The button 12 includes a shank portion 13 positioned within an opening 14 in a sheet metal plate 15 which may be a part of an electrical or electronic chassis, being secured therein by a retaining nut 16 or other suitable means (not shown). As seen in FIGURE 2, the button 12 includes an upper generally planar surface 18, a slightly tapered side surface 19, and a lower edge surface 20. The upper surface 18 meets the side surface 19 Patented Oct. 11, 1966 in an upper curvilinear edge 21, the side surface meeting the lower surface 20 in a similar curvilinear edge 22.

The device 10, as has been mentioned is formed integrally to include a body of flexible resilient material, such as silicon rubber, natural rubber, or the like, and includes a generally planar upper wall 25 adapted to overlie the upper surface 18, the same being bounded by an outer surface 26 and an inner surface 27 as well as a peripheral edge 28. Interconnected at the edge 28 is a tapered side wall 29 corresponding to the side surface 19, again including an outer surface 30 having ribbed elongated projections 31 thereon to facilitate manual engagement, and a relatively smooth inner surface 32 adapted to frictionally grip the surface 19. The side wall 29 includes a lower edge 33, of arcuate configuration, to which are attached a first inwardly directed flange 34 and a second outwardly directed flange 35. The flange 34 lies substantially in a plane parallel to that of the upper wall 25, and overlies the lower surface 20 to a degree suflicient to retain the device 10 upon the button 12. The flange 35 is flared radially outwardly in a direction away from the upper wall 25, and is best seen in FIGURE 2. The same is formed to include a tapered cross section which converges to a feathered edge 36 at the point of contact with the surface of the plate 15, whereby a gentle resilient pressure is constantly exerted upon said surface sufficient to maintain a hermetic seal thereat. This sealing action may be assisted, if necessary, by the use of a small amount of silicone grease at the area of contact, but is by no means essential.

I wish it to be understood that I do not consider the invention limited to the precise details of structure shown and set forth in this specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.

I claim:

A cap-type seal for use in conjunction with a rotating knob, comprising: a unitary molded body of flexible resilient material, said body having a principal axis, and including a substantially planar outer wall disposed perpendicularly to said axis, a continuous curvilinear side wall interconnected at one peripheral edge thereof to said outer wall and forming a recess for reception of said knob, said side wall having a second oppositely disposed peripheral edge, a first radially inwardly directed flange connected to said side wall at said second peripheral edge, said inwardly directed flange having an inner diameter substantially less than the greatest diameter of said recess when said seal is in relatively unstressed condition, and a second outwardly directed flange also connected to said side wall at said second peripheral edge, said second outer flange being flared in a direction away from said outer wall, and having a free edge portion thereof of tapered cross section, said second outer flange defining a feathered edge lying in a plane perpendicular to said principal axis.

References Cited by the Examiner UNITED STATES PATENTS 2,440,170 4/ 1948 Duefrene. 3,101,205 8/ 1963 Benham. 3,185,806 5/1965 Bowman et a1 200168 3,218,427 11/ 1965 Mekel burg 200168 OTHER REFERENCES Westinghouse, November 1959; Product Engineering (design edition) vol. 30, #46, pp. 12-13.

FRED C. MATTERN, 111., Primary Examiner.

C. F. GREEN, Assistant Examiner.

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