US2748229A - Water tight switch - Google Patents

Description

y 9, 1956 E. H. BLOCK 2,748,229

WATER TIGHT SWITCH Filed Dec. 1, 1953 FIG.1. 33 IO 4 I I I8 F I 3 [a m [31 IO 25 3! 2a I6 3437 39 r 2 8) 43 --38 37 N I4 I27) 4544 2 35 47 INVENTOR EDWIN H. BLOCK ATTORNEYS 2,748,229 7 WATER TIGHT SWITCH Edwin H. Block, Austin, Tex., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application December 1, 1953, Serial No. 395,635

2 Claims. (Cl. 200-169) The present invention relates to a cam operated switch. More particularly the invention relates to a cam operated water-tight switch mechanism wherein one or more microswitches are operated by depressing a plunger mounted exteriorly of the casing in which the switch is mounted, the mechanism being held in the operated position by a ball lock which may be released by depressing a second plunger mounted interiorly of the casing. In the locked or operated position the micro-switches are held positively by the ball lock to prevent further actuation thereof by shock or vibration or by accidental contact with the first plunger.

An object of the present invention is to provide a new and improved switch mechanism which is locked positively in the operated position thereof.

Another object is to provide a new and improved switch mechanism which while positively locked against release from the operated position by shock and vibration is readily released manualy to the unoperated "position, if desired.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a longitudinal sectional view of the switch 2,748,229 Patented May 29, 1956 and a hollow substantially cylindrical plug 28 set in the inner end of casing 10 to normally urge member 26 against the shoulder 13. Plug 28 is provided with a circumferential groove 29 containng a ring 31 which is engaged by a nut 32 threaded on the inner end of casing 10. Plug 28 has integrally formed thereon and extending to one side of the axis thereof a switch supporting plate 33.

Plug 28 is provided with an axial bore 34 to receive tubular member 25, bore 34 being formed with an enlarged ball-receiving groove or recess 35 for a purpose to be hereinafter more fully described.

Tubular member 25 has a plurality of transverse bores 36 formed therein, each of which receives a ball 37, the balls 37 intially engaging rod 38. Rod 38 is mounted in reduced bore 39 formed in the end of tubular member 25 which projects exteriorly of plug 28, this portion of memi head 42 are urged in a direction toward balls 37 by spring mechanism of the present invention in the unoperated position;

Fig. 2 is a view similar to Fig. l and showing the device in the operated position;

Fig. 3 is a view similar to Fig. l and showing the release position for the ball lock; and

Fig. 4 is an end elevation of the device.

Referring more particularly to the drawings wherein lilre numerals indicate like parts throughout the several views, 10 indicates generally a switch casing which is mounted in wall 11 of a device which is utilized in water. Casing 10 has formed therein an axial bore 12 having a shoulder 13 spaced from the outer end thereof. The casing 10 is also formed with an external shoulder 14 which abuts the inner face of wall 11 adjacent a bore 15 through which casing 10 extends. The outer end and shoulder 14 of casing 10 may be welded or otherwise secured to wall 11 as at 16. In order to ensure a water-tight connection between casing 10 and wall 11 a ring of silver solder 17 is heat sealed in groove 18 in casing 10 and engages bore 15.

Slidably mounted in bore 12 is a plunger 19 having a head or pushbutton 21 initially extending exteriorly of bore 12 and beyond the outer face of wall 11. Plunger 19 is provided with a groove 22 in which is mounted an O ring gasket 23 for preventing ingress of water to the interior of casing 10. Plunger 19, at the inner end thereof, is provided with a reduced threaded extension 24 and a tubular member 25 which is threaded on extension 24, the member 25 having an annular member 26 formed integrally thereon and intially engaging the shoulder 13 of bore 12. A spring 27 is interposed between member 26 44 interposed between threaded portion 24 of plunger 19 and head 42. Adjustment of the compressive strength of spring 44 may be accomplished by relative movement between threaded extension 24 and tubular member 25. Plunger 19 has extending into spring 44 a reduced extension 45 which limits the motion of rod 38. Extension 45 may also serve to engage and positively move head 42 should the urging of spring 44 be insufficient to do so because of inertia and/or friction when the plunger is moved inwardly.

Mounted on supporting plate 33 are a pair of microswitches 46 and 47, each switch having mounted thereon a spring arm 48 which engages reduced end 49 of tubular member 25, as shown particularly in Fig. 1. Spring arms 48 overlie operating pins 51 in switches 46 and 47 whereby pressure thereon by arms 48 operate the mechanisms of the switches (not shown) to open or.closethe contacts thereof, as the case may be, thus to open or close electrical circuits controlled by the switches.

In operation, the plunger 19 is moved inwardly, in any desired manner, compressing spring 27, until balls 37 reach recess 35, whereupon tapered portion 43 of head 42 urged by spring 44 or moved by extension 45, as the case may be, forces balls 37 outwardly, the balls being part way into recess 35 and part way in bores 36, the head 42 moving to the position indicated in Fig. 2, thus to lock the balls in the recess 35 and bores 36. As plunger 19 is moved inwardly, cam surface 41 of tubular member 25 forces springs 48 against operating pins 51, as aforedescribed, to operate switches 46 and 47.

As shown in Fig. 2 of the drawings, the springs 48 are held firmly against operating pins 51 when tubular member 25 is locked against movement by balls 37, thus pre venting chattering or accidental operation of the switches by vibration or shock.

If desired the switch mechanism may be returned to the initial position by pressing in the direction of the arrow on the end of rod 38, compressing spring 44 and moving head 42 from the retaining position with respect to balls 37, as shown in Fig. 3. Spring 27 returns tubular member 25 to the initial position and springs 48 are released by cam surface 41 to the position of Fig. 1, freeing pins 51 to return switches 46 and 47 to the unoperated position. Should the static friction of 0 ring gasket 23 and the inertia of the plunger be so great that the spring 27 is unable initially to overcome the same, continued pressing in the direction of the arrow, Fig. 3, will cause end 49 to be engaged and tubular member 25 to be moved toward the initial position.

It will thus be seen that the apparatus of the present invention provides a switch mechanism which locks positively in the operated position against movement caused by vibration or shock and which is readily resettable to the initial or unoperated position.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Apparatus for operating and locking electrical switches comprising, in combination, a hollow cylindrical housing, means on one end of said housing for supporting said switches thereon, said switches having spring actuating arms mounted thereon, a hollow plunger slidably mounted in said housing, said plunger including a tubular member and a pushbutton member threaded in one end of the tubular member, cam means on the other end of said tubular member, a spring sleeved about said tubular member and adapted to urge the plunger into an unoperated position, said plunger being adapted to be manually moved into an operated position by pressure on the pushbutton member from the exterior of the apparatus, said cam means being adapted to engage said spring actuating arms when the plunger is in the operated position thereby to energize the switches, a ball locking groove in the housing, ball locking means in said plunger and adapted to move into locking engagement with the ball locking groove when the plunger is in the operated position, yieldable means in said tubular member for urging the ball locking means into engagement with said ball locking groove, said yieldable means including a movable element engaging the ball locking means and a compression spring interposed between said element and pushbutton member, relative movement between the threaded pushbutton member and tubular member serving to adjust the compression of the compression spring, and a rod-like extension on said element passing through said cam means and adapted to receive pressure from the exterior of the apparatus for moving the element toward the pushbutton member against the urging of the compression spring and unlocking the ball locking means; thereby allowing the plunger to return to an unoperated position and deenergizing the switches.

2. Apparatus for operating and locking electrical switches comprising, in combination, a hollow cylindrical housing, means on one end of said housing for supporting said switches thereon, spring actuating arms for said switches mounted on said means, a hollow plunger slidably mounted in said housing, a spring sleeved about said plunger and adapted to urge the plunger into an unoperated position, said plunger being adapted to be manually urged to an operated position from the exterior of the apparatus, cam means on one end portion of said plunger and adapted to engage said spring actuating arms when the plunger means is in the operated position thereby to energize the switches, support means fixed in the other end portion of said plunger and including an element extending toward the cam means, a ball locking groove in the housing, ball locking means Within said plunger and adapted to move into locking engagement with the ball locking groove when the plunger is in the operated position, rod means slidably mounted within said plunger, said rod means having a tapered portion and a portion of reduced diameter extending through the cam means, and spring means in said plunger encircling said element and urging the tapered portion of said rod means into engagement with said ball locking means, the tapered portion of said rod means being effective to urge the ball locking means into engagement with said ball locking groove when said plunger is moved to an operated position, said element being effective to engage and positively move the rod means should the same fail to move under the urging of the spring means, said portion of reduced diameter of the rod means being adapted to receive pressure thereon from exterior of the apparatus in a direction opposite to the urging of said spring means for manually moving said tapered portion and thereby rendering the ball locking means ineffective and releasing the plunger for return to an unoperated position.

References Cited in the file of this patent UNITED STATES PATENTS 756,049 Pitel Mar. 29, 1904 999,850 Palmer Aug. 8, 1911 1,014,300 Hart Jan. 9, 1912 1,582,987 Hart May 4, 1926 2,658,123 Stoeser Nov. 3, 1953

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