US 3286047 A
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Description (OCR text may contain errors)
1966 s. M. HElDE 3,235,047
HERMETICALLY SEALED THUMBWHEEL ROTARY SWITCH Filed Nov. 10 1965 I NV If N TOR.
United States Patent Dynamic Industries, Inc., Chicago, 11]., a corporation of Illinois Filed Nov. 10, 1965, Ser. No. 507,097 2 Claims. (Cl. 200-41) My invention relates to a hermetically sealed thumbwheel rotary switch and has for its principal object the provision of improved construction of this character which will be highly efficient in use and economical in manufacture.
Among the objects of my invention is the provision of a simple and effective arrangement for hermetically sealing the switching area of a rotary switch against the admission of moisture, dirt, grit and other contaminations of such switching area as well as hermetically sealing the enclosure of such area and the panel to which it is mounted.
Other objects will appear hereinafter.
The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.
The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:
FIG. 1 is a perspective view of my invention;
FIG. 2 is a rear elevational view of the same;
FIG. 3 are perspective views of parts of the invention showing the same in exploded relation with respect to each other;
FIG. 4 is a vertical sectional detail view through the thumbwheel housing;
FIG. 5 is a sectional view taken substantially on line 5-5 of FIG. 3;
FIG. 6 is a perspective view of a switch wiper disc;
FIG. 7 is an edge view of the same;
FIG. 8 is a sectional detail view taken on line 88 of FIG. 3.
The several objects of my invention are accomplished by the preferred form of construction shown in the accompanying drawings. In this connection 10 indicates a mounting bracket having a plurality of bolt-receiving openings 11 through the medium of which bolts (not shown) the bracket 10 is mounted to a panel (-not shown). The bracket comprises a wall 12 and parallel rearwardly extending arms 13. The wall 12 has an elongated opening 12 formed therein through which is exposed the operator portion of an indicia-bearing thumbwheel 14. Such Wheel has finger lugs 15 through the medium of which the wheel 14 is rotated.
A switch casing is indicated at 16. Such casing 16 includes top and bottom walls 17 and an end wall 18 of the width less than the width of the top wall 17. The side opposite the Wall 18 is open as at 19. Mounted in the casing 16 and secured to the walls 17 and 18, preferably though not necessarily, by spot welding, is aU-shaped bracket 20 comprising parallel arms 21 which are positioned in coplanar relation with the walls 17. These arms 21 are L-shaped in cross section to provide flanges 22 for the mounting of an assembly 23 having a switching area 23.
This assembly 23 includes a plate 24 of non-conductive material and on which the circuit 25 is printed, there being suitable pig tails 26 for connecting circuit wires to the printed circuit 25.
Disposed over the printed circuit 25 is spacer block 26 of non-conductive material. This spacer block 26 is disposed between the plate 24 and a plate 24'. The assembly 23 is positioned between the arms 21 of the bracket 20 and against the flanges 22. Disposed between the assembly 2'3 and the flanges 22 are sealing strips 27 which may be of any approved construction.
There is positioned a sealing strip on the surface 28' of the plate 24 to seal the assembly 23 with respect to the casing 16 along the peripheral edges 18' of the bight 29 and the wall 18. i V
The casing 16 is positioned between the arms 13 and spaced therefrom by spacer sleeves 31 disposed between the arm 13 .and the adjacent walls of the casing 16. Screws 32 project through openings 33 and the sleeves 31 to securely mount the casing 1 6 to the mounting bracket 10. v I 1 On the inside surface 34 of the wall 12 and along the peripheral edge of the opening 12 is a sealing collar 34' which effectively seals the casing 16 and the edge 28 of the assembly 23 with respect to the wall 34, thus to prevent the admission of moisture, dirt, grit, or any other contaminations into the assembly 23 through the opening 12.
The block 26 has formed therein an opening 35. Formed in the plate 24 and centrally with respect to the opening 35 is an opening 36. Surrounding this opening 36 is a cup-shaped collar 37.
In the hub 38 of the thumbwheel 14 within a recess 40 is a resilient O ring 39 which is of a diameter to be compressed into the cup-shaped collar 37, thereby to provide an effective seal between the collar and the hub whereby to prevent moisture and other contaminants from entering the assembly at this area.
The wheel 14 is rotatably mounted upon a pintel 14' struck inwardly from the wall 16' of the casing 16 and adapted to project in a socket 41 formed in the wheel 14.
Mounted in the opening 35, between the printed circult-carrying plate 24 and the plate 24', is a switch disc 42 having struck therefrom spring contact fingers 43 which are adapted to engage the printed circuit 25. This disc has a circular hollow hub 44 (FIG. 6) which spaces the disc 42 with respect to the adjacent surface of the plate 24 so that the contact fingers 43 will have the proper resilient bearing contact with the printed circuit 25.
In the center of the hub 44 is a square-shaped opening 45 which receives a stud shaft 46 of like formation carried by the wheel 14 whereby to provide rotatable connection between the wheel 14 and the disc 42.
The assemblv is connected to the bracket 20 by means of screws 47 which are threaded into openings 48 formed in the flanges 22 (FIG. 3).
To complete the invention there is provided a detent spring 49 mounted by means of the stud 29' and finger 49' on the bight 29 of the bracket 20 in the manner shown in FIG. 4, and engageable with the thumbwheel 14 for properly indexing the wheel.
From the foregoing description it will be seen that the switching area within the assembly 23 is hermetically sealed and that the casing 16 enclosing such area is also hermetically sealed around the area of the thumbwheel opening 13 as is the hub portion of such thumbwheel, thereby to seal against the admission of moisture and other contaminants. As a result a switch is provided which has a high degree of operation efliciency, free from moisture, dirt, grit, and other contaminations.
While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.
Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:
1. A rotatable thumbwheel switch comprising (a) a mounting bracket'having an elongated opening formed therein,
(b) a casing carried by 'said bracket with one end surrounding said opening and hermetically sealed with respect to said bracket,
(c) a thumbwheel rotatably carried by said casing with an operator portion exposed through said opening, (d) an assembly including a printed circuit and a wiper switch therefor arranged in said casing,
(e) a hermetical seal between said assembly and said casing,
(f) a connection between said wiper switch and said thumbwheel, and
(g) a hermetical seal at the area of connection between said thumbwheel and said wiper switch.
2. A rotary thumbwheel switch comprising (a) a switch casing,
(b) a mounting bracket within said casing including a pair of flanges in spaced parallel relation with respect to each other,
(c) a hermetical seal assembly including a printed circuit and a wiper switch therefor mounted in said casing against said flanges,
(d) a hermetical seal between said flanges and said assembly,
(e) a thumbwheel rotatably mounted in said casing and having rotatable connection with said wiper switch, and
(f) a henmetical seal at the point of connection of rotation between said wiper switch and said thumbwheel References Cited by the Examiner UNITED STATES PATENTS 2,565,863 8/1951 Linn 200l68 3,089,923 5/1963 Wright 20011 3,104,299 9/ 1963 Koci et a1 20011 X 3,222,465 12/1965 Huntress et a1 200-11 3,222,490 12/1965 Huntress et a1. 200l68 ROBERT K. SCHAEFER, Primary Examiner. I. R. SCOTT, Assistant Examiner.