US2321012A - Electrical switch - Google Patents

Description

Patented .lune ti, i943 UNlTED STATES rATENr ort-mg (Granted under the act oi March 3, i353, as

amended April. 30, 1923; 370 O. G. l?)

l@ Claims.

My invention relates to electrical switches, and in particular to the type of switch which is constructed for use under water for controlling electrical apparatus such as, for example, electric welding guns.

This application is a continuation-in-part of my application, Serial No. 362,714, filed Cctober 25, llili, for Subaqueous end wending device.

a general object of my invention is to provide an improved electrical switch which is suitable for manual operation under water.

Another object is to provide a switch adapted i'or undenwater operation in which the force of the water acting upon the switch contact operating member and tending to close the switch contact is counteracted by an opposing force set up in an opposite direction.

Another object of my invention is to provide e. switch which can be adjusted to compensate for water pressure acting upon the switch oper ating member so that the switch may be useful at various depths of water.

Another object is to provide a switch in which the operating member thereof can be actuated with substantially the same manually applied torce irrespective of the distance which the switch may be located below the surface of the water.

A further object of my invention is to provide a switch adapted for under-water operation which can be controlled automatically and remotely by applying a pressure from an auxiliary source oi iiuid supply to the switch contact operating member in such manner as to oppose the pressure of the water acting upon such member. The applied pressure is so regulated that when the force created thereby is greater than the force of the water acting upon the contact operating member, the switch contacts will be maintained open, but when such force is less than that due to the water pressure, the operating member will yield to 'the force of the water and close the switch contacts.

A still further object is to provide an underwater switch which is so calibrated that the operator can quickly and accurately adjust the pressure compensation mechanism to balance the water pressure acting upon the switch operating member at the depth of water at which he may be working.

These and other objects of my invention will become more apparent from the following detailed description, and from the accompanying drawing, in which:

Fig. 1 is a side view, partly in section, of a switch embodying my invention;

Fig. 2 is a sectional side -view of a modified form of switch;

Fig. 3 is a view taken on lines 3 3 of Fis. 2c; and

Fig. 4 is a sectional side view ci another modication of a switch embodying my invention.

Referring now to Fig. l, my improved switch apparatus comprises a casing i which may be of any waterproof, electrically insulating material such as bre, within which is carried the switch contacts. If desired, these contacts may be completely assembled in a separate casing i from which a plunger El extends, the latter being operable when depressed to close the switch contacts. A suitable contact assembly is shown in U. S. Patent No. LQSGgG/u.

The housing l may be secured in position by inserting it between the side walls of a U-shaped clamping member Ei and securing it in such position by means of screws Ears are provided on the U member 6 and these rest upon an internally shouldered portion of the casing I. The U member 6 may be secured to the casing l by means of screws, which pass. through apertures in the ear portions of the member and thread into the casing.

Resting upon the top' of the U member is a resilient body member 5 which may be made oi cellular rubber or any other suitable material.

A flexible diaphragm 2, which may also be made of rubber, is placed over the resilient member 5 and is secured to the casing by means of a rigid plate member 3 which may be made of metal, if desired. This plate member 3 includes an apertured portion within which a switch button 4 is located. A stud portion of switch button 4 passes through an opening in the flexible diaphragm 2 and is secured tightly within such opening by a nut and washer. When button 4 is depressed the studded portion thereof presses upon and moves the plunger 8 which operates to close the contacts within the housing 1.

Leads I0 from the switch contacts may b e carried out of the casing through a stuiling box I I.

When the switch is immersed in water, the pressure of the -water (which increases with depth at the rate of approximately 62.5 lbs. per sq. ft. for each foot of depth) acting upon the exposed area of the flexible diaphragm 2 will tend to move the diaphragm 2 and button l towards the plunger 8. Such movemet is opposed, however,V by the restoringiorce set up within the resilient body member 5 as the latter is compressed, which prevents untimely actuation of plunger 8 by the button 4, thereby preable screws.

venting the .switch contacts from being moved to a closed position.

Cellular rubber may be obtained in varying degrees of resiliency. Hence the particular type utilized for member will be so chosen that for a given pressure of water (which will be determined by the distance below the surface of the water that the apparatus on which the switch is installed is intended to operate), it will prevent the button I from traveling a distance sumcient to abut the'plunger 8. The additional force necessary to'cause the button l to abut and depress plunger 3 can then be supplied manually.

In Figs. 2 and 3, I have illustrated a modified form of switch which is adapted `to operate at depths greater than those at which a switch made in accordance with Fig. i can operate. The switch has a casing I2 which may be of the same material as the casing I. In this particular embodiment, the casing I2 is rectangular but it is obvious that it may be of any suitable shape. Within the casing I2 is a rigid metallic support member 2| which has a central aperture cut therein and rests upon an internally shouldered portion of the casing and secured thereto by suit- A resilient body member I1 v.which is nonporous, such as cellular rubber, is provided with a central apertured portion and rests upon the support 2i. Member I1 is tlxed in position by a non-porous diaphragm I3 of ilexible material such as rubber which is clamped at its periphery betweeny `a pair of rigid members I 4 and i6. These latter members, with the iiexible diaphragm I3 therebetween are secured to the casing i2 by a bolt and nut at each corner thereof.

Amanually operable button I5 extends through a central opening in diaphragm I3 and is secured thereto by a nut I 9 which threads on the shank portion Il' of button I5.

A T-shaped contactor having a stem 20' is similarly secured through th'e apertured portion of a second ilexible diaphragm 22 by nut I9.

A pair of switch contacts 23-23 are fastened in position to inwardly projecting tongue portions 29 in the casing I2 by means of screws. Leads -25 soldered to lugs 24-24 are taken out through a stumng box 26.

It will be noted that the outer periphery of resilient member I1 is spaced from the internal wall of casing I2, thus leaving a chamber I1' which extends around the casing. This chamber connects with the exterior of the casing I2 through a pipe 23 which threads into a threaded opening 21 in the casing I2. To prevent seepage of Water or other fluid from the chamber I1 to the central opening in the resilient member I1, the top and bottom surfaces of the latter may be glued respectively to the diaphragm AI3 and disc 2 I.

If the pipe 23 is sealed, operation'of the switch is similar to that in Fig. 1. The switch would be utilized in this manner when the water presand to thus increase the opposing force which this member presents to resist depression of the ilexible diaphragm by the force of the water acting downwardly thereon.

If the pressure in chamber I1' does not sufficiently oii'set the pressure of the fluid acting downwardly on diaphragm I 3, the pipe 2l may be connected to a separate source of uid supply (not shown), and iluid pumped into the cham- -ber at the desired pressure. This fluid may be liquid or gas, such as compressed air.

Manual operation is similar to that in Fig, l.

This type of construction permits the switch contacts 23.23 to also be operated automatically, if desired, instead of manually.

To effect automatic operation, iiuid would be pumped into chamber I1' until the total force acting upwardly against the under side of the diaphragm I3 is greater than the total force exerted downwardly on the upper side of the diaphragm I3 by the water. This excess of force on the under side of the diaphragm would be just suillcient to keep the shank portion I5' of button I5 out of engagement with the stem 2l'. When it is desired to close the switch, a valve in the I uid supply line would be opened, whereupon the pressure due tol the fluid in chamber I1' would be released. Since the total force of the water acting downwardly upon the diaphragm would then be greater than the opposing force Y set up on the under side of the diaphragm, the

diaphragm would then move downwardly, causing button shankA I5 to engage the stem 20' of contacter 20 and move the latter until it bridges and closes a circuit through contacts 23-23.

To open the circuit, fluid -would again be pumped into chamber I1' until the pressure was suilicient to cause contactor 20 to move upwardly and break its engagement with contacts 23-23.

In Fig. 4 I have provided another .type of construction whereby the force of the water acting downwardly against the upper side of the ilexible diaphragm may be balanced at any depth by a counterforce acting upwardly against the under side of said diaphragm.

In this modification the switch comprises a base plate 49 upon which a cylindrical casing 3l f is mounted for rotation. A plurality of graphite sure acting upon the water exposed surface of plugs 4I are provided in order that the casing may rotate easily upon the base plate 40, and a stuillng box 33 together with a gland 39 prevents water from entering the interior oi the switch as the casing 30 is rotated.

An annular disc member 3B is provided with threads at the periphery thereof and these threads engage with complementary threads Il which are provided on the insidewall of the' casing 30.

One or more guide members 31, which are fixedly secured to the base plate l0, extend upwardly through aligned openings 49 provided in the disc 33 and function to prevent the disc 39 from rotating with the casing 39 as the latter is turned on base plate 40.

Since disc 36 cannot rotate, the interaction between the threads will cause it to move in translation upwardly or downwardly. depending upon the direction in which the casing 39 is rotated.

'I'he top of the casing 30 is closed by a ilexible diaphragm member 3| and, if desired, an anthereby serves to stiifen the resilient member nular shaped rigid member 33 may also be provided to assist i: n'clamping the diaphragm 3| to the casing 30 to make it watertight. A coiled asesora spring member it is seated upon an upturned portion of the disc 35 and is secured in position between the disc 36 and iiexible diaphragm 3l.

A contactor 35 is secured to diaphragm 3| by nut 32 which serves as a manually operable switch button. Contactar 35 extends downwardly into the body of the switch and terminates in an i. which is provided to bridge a pair of circular switch contact members 42 and 43 which are supported, respectively, on cylindrical posts M3 and t?. Leads lllt4 may be respectively connected to each contact member and are carried to the outside of the switch through a stuffing box which may be provided in base plate riti.

This type of switch operates in the following manner: When the switch is taken below the surface of the water, it is evident that a force due to the pressure head of the water will act upon the flexible diaphragm 3| and tend to depress it. This torce can be counteracted, however, by tux/ninor the cylindrical casing 3i) on base plate it in such a direction as to cause the disc tit to move upwardly and compress the coiled spring mi. The restoring force which is thus built up in the coiled spring, due to its cornpression, will act upwardly against the under ci the flexible diaphragm 3l and balance out the for-ce of thewater on the opposite side of the diaphrag, v

have also provided indicator means wherethe operator of the switch may adjust the compression on the coiled spring St below the suriace of the water to suit the particlar depth which he is working. a plurality ci lugs which are spaced around the periphery of the base plate lli), and an indicator arm which is attached to and rotates with the casing Consecutive lugs 5i may be marked with depth settings in any suitable intervals, such as, for example, 25 it., 50 it., 75 etc. i unable to see the indicia on the lugs. operator, knowing the characteristics of the proper lug iii by tactile sense.

conclusion, while E have shown and described certain embodiments or my invention, it 1 be apparent that changes and modifications be made therein without departing from the spirit and scope oi my invention, as defined in the appended claims.

For example, in some instances it may be desirable to replace the cellular rubber member in ig. 'l with a spring member such as member shown in Fig. t. Also, in some cases, it may be desirable to insert a rigid disc member between the top oi the coil spring 34 and the flexible diaphragm 3i in order to better distribute opposing force set up by the spring over the entire surface of the diaphragm.

As another example, it may be desired to substitute a coil spring such as member 34 shown in Fig. 4 to replace resilient member l1 in Fig. In such case disc 2l is secured to causing l2 by a water-tight connection and second flexible diaphragm 22 is made up with a water-tight joint to disc 2l.

Also, while I have described my invention in connection with its use as an under-water switch, it will be evident that it may be used equally as Well in other fluid mediums such as compressed air.

The invention described herein may be manuiactured and used by or for the Government of Such means comprise the United States of america for governmental purposes without the payment ol' any' royalties thereon or therefor. f

Having fully described my invention, claim:

In a switch adapted for use under iiaid presn sure` such as in under-water operation, the com-1 bination comprising a switch casing, switch contact means, means for supporting contact means within said casing, a flexible diaphragm closure member for said casing, means operable upon a depression of said closure member.' to actuate said contact means, a support and a resilient pad member disposed between the underside of said diaphragm closure member and said support, said resilient member being be distorted upon depression of said ciosure member whereby the restoring force created therein will be exerted outwardly against said closure mem ber to oppose uuid pressure acting thereupon in an opposite direction.

2. In a switch adapted for use under fluid pressure such as in under-water operation, the comclosure member for said casing, a movable switch member operable upon a depression of said closure member to bridge said stationary contact members to close a circuit therethrough, a support plate, and a resilient pad member disposed between said support plate and the underside of said diaphragm ciosure member, said resilient member being adapted to be compressed upon depression of said closure member whereby the restoring force created therein will be exerted outwardly against said closure member to oppose uid pressure acting thereupon in an opposite direction.

3. .it switch adapted for use under fluid pressure such asin under-water operation comprising a easing, switch contact means disposed therein, a flexible diaphragm closure member for said casing, means operable upon depression of said diaphragm member to actuate said contact means, and means for admitting fluid under pressure to the interior of said casing to oppose fluid pressure acting upon the exterior ci said diaphragm member.

In a switch adapted for use under :duid pressure such as in underwater operation, the cornbination comprising a switch casing, a flexible diaphragm ciosure member for said casing, a support plate, a non-porous resilient member disposed between said .support plate and the under side of said closure member, said resilient member being spaced from the inner wall of said casing to form a chamber therebetween, means for admitting uid under pressure to said chamber, switch contact means, and means operable upon adepression of said flexible diaphragm member to actuate said contact means.`

5. In a switch adapted for use under fluid pressure such as in under-water operation, the combination comprising a base plate, a. cylindrical casing, the inner wall of which is threaded, means for supporting said casing on said base plate for rotation thereon, a disc member, the periphery of which isthreaded for threaded engagement with the threaded inner wall of said casing, an upstanding guide member secured to said base plate, said guide member being extended through an aligned opening in said disc whereby rotation of said casing upon said base plate will produce translatory motion of said disc, a exible daphrasm. means securing said diaphragm to said cylindrical casing toclose the latter, a resiiient member, said resilient member being supported between said diaphragm and said disc so that as said resilient member is compressed by translatory motion o! said disc the restoring force created therein will oppose fluid pressure acting upon said ilexible diaphragm.

7. In a switch adapted for use under fluid pressure such as in under-water operation, the combination comprising a base plate, a cylindrical casing, the inner wall of which is threaded, means for supporting said casing on said base plate for rotation thereon, a disc, the periphery of which is threaded for threaded 'engagement with the threaded inner wall oi' said casing, an upstanding guide member secured to said base plate, said guide member being extended through an aligned opening in said disc whereby rotation of said cas- 'ing upon said base plate will produce translatory motion of said disc, a ilexible diaphragm, means securing said diaphragm to said cylindrical casing to close the latter, a spring, said spring being supported between said diaphragm and said disc so that as said spring is distorted by translatory ,motion of said disc the restoring force created therein will oppose iluid pressure acting upon said diaphragm, switch contact means, and means operable upon depression of said flexible diaphragm to actuate said contact means.

8. The 'combination in claim 'I and including indicator means associated with said casing whereby its position may be set to apply to said spring member the amount oi' distortion necessary to balance the fluid pressure acting upon said iiexible diaphragm.

9. In a switch adapted for use under :duid pressure such as in under-water operation, the combination comprising a base plate, a cylindrical casing, the inner wall of which is threaded, means for supporting said casing on said. base plate for rotation thereon, an annular disc, the periphery oi which is threaded i'or threaded engagement with the threaded inner wall of said casing, an upstanding guide member secured to said base plate, said guide member being extended through an aligned opening in saiddisc whereby rotation of said casing upon said base plate will produce translatory motion of said disc, a iiexible diaphragm, means securing said diaphragm to said casing to close thelatter, a coiled spring member, said spring being supported between said diaphragm and said disc so that as said spring is compressed by translatory motion of said disc the restoring force created therein will `opose fluid pressure acting upon said diaphragm, a pair oi' circular switch contact members, means for mounting said contact members concentrically on said base plate, and means operable upon depression of said diaphragm to bridge said contact members.

10. In a switch adapted for use under fluid pressure such as in under-water operation, the

combination comprising a base plate, a cylindrical casing, means for supporting said casing on said 'base plate for rotation thereon, a disc member disposed within said casing, means operable upon rotation of said casing to eiect translatory moe tion of said disc member, a flexible diaphragm,

means securing said diaphragm to said casing to close the latter, a resilient member, said resilient member being supported between the under side of said diaphragm and the upper side of said disc member sothat as said resilient member is compressed by translatory motion of said disc member the restoring force created therein will oppose fluid pressure acting upon said diaphragm, switch `contact means, and means operable upon depression of said flexible diaphragm to actua said contact means.

JOHN D. CRECCA.I

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