US3325607A

US3325607A - Mercury time delay switch

Info

Publication number: US3325607A
Application number: US41537A
Authority: US
Inventors: Sidney V Worth
Original assignee: Elco Corp
Current assignee: Elco Corp
Priority date: 1960-07-08
Filing date: 1960-07-08
Publication date: 1967-06-13
Anticipated expiration: 1984-06-13
Also published as: CH371170A; FR1284298A; DE1197529B; GB979798A

Description

June 13, 1967 s. v. WORTH 3,325,607,

MERCURY TIME DELAY SWITCH Filed July 8, 1960 Fig. l

2 Sheets-Sheet 1 Fig.

INVENTOR. SIDNEY V. WORTH BYMKW ATTORNEY 7 June 13, 1967 s. v. WORTH 3,325,607

MERCURY TIME DELAY SWITCH Filed July 8, 1960 2 Sheets-Sheet 2 INVENTOR. SIDNEY V. WORTH BY N I ATTORNEY United States Patent Pennsylvania Filed July 8, 1960, Ser. No. 41,537 25 Claims. (Cl. 200-33) The present invention relates to an electric switch, and more particularly to an electric mercury switch having a time delay between the actuation of the switch to one of its positions and the actual opening or closing of the switch.

For the operation of many types of electrically operated devices, it is often desirable to have a switch provided with a time delay. The time delay may be between the actuation of the switch to its on position, and the actual closing of the switch, but will provide substantially no delay between the actuation of the switch to its oif position and the opening of the switch. Furthermore, it is often desirable to provide a time delay switch wherein the delay time is between the actuation of the switch to its off position and the actual opening of the switch, but will provide substantially no delay time between the actuation of the switch to its on position and-the actual closing of the switch. In certain operations it is desirable to have a delay time between actuation of the switch to its open and closed position and the actual opening and closing of the switch.

Furthermore, it is also desirable to have a time delay switch in which the delay time can be varied. In order to preclude the possibility of loss of liquids in the switch, it is desirable to seal the switch housing. Therefore, the means for varying the delay time must be external of the switch housing and preferably should not pierce od extend through the wall defining the switch housing.

Heretofore, it has been conventional to use mercury .in time delay switches. Since mercury has a large amount of surface tension, there was a limit to the minimum size of the flow passage through which the mercury flows as the switch is moved between its off and on positions. Thus, the size of the flow passage for the mercury presented a limit to the amount of timedela'y which can be obtained with a mercury time delay switch,

It is an object of the present invention to overcome the above and other disadvantages of the prior art.

It is another object of the present invention to provide a novel time delay switch.

It is another object of the present invention to provide a novel mercury time delay switch having a delay period between the actuation ofthe switch to its on position and the actual closing of the switch. i

It is another object of the present invention to provide a novel mercury time delay switch having a delay period between the actuation of the switch to its off position and the actual opening of the switch.

It is still another object of the present invention to provide a novel mercury time delay switch wherein the time delay capable of being obtained is not dependent on the size of the flow passage for the mercury.

It is still another object of the present invention to provide an electric switch having a delay period between the actuation of the switch to its on position and the actual closing of the switch, but having substantially no delay time between the actuation of the switch to its off position and the opening of the switch.

It is still another object of the present invention to provide an electric switch having a delay period between the actuation of the switch to its off position and the actual opening of the switch, .but having substantially no delay time between the actuation of the switch to its on position and the closing of the switch.

.

end walls

14 and 16. A partition 18, positioned intermediate the

walls

14 and 16 and parallel thereto, divides 3,325,607 Patented June 13, 1967 It is a further object of the present invention to provide an electric switch having a time delay which may be varied.

It is a further object of the present invention to provide a novel switch wherein the time delay can be ex tended by the provision of a liquid above the mercury in said switch, and having means for controlling the flow of said liquid.

It is a further object of the present invention to provide a novel mercury timedelay switch wherein the delay time can be controlled by a valve member which does not extend through the housing of said switch,

It is a still further object of the present invention to provide a mercury time delay switch which is simple, easy to manufacture and contains a minimum number of parts.

Other objects will appear hereinafter.

For the purpose of illustrating the invention there is shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a cross-sectional elevational view of one embodiment of the present invention.

FIGURE 2 is a cross-sectional view lines 2-2 in FIGURE 1.

FIGURE 3 is a perspective view of the switch shown in FIGURE 1.

. FIGURE 4 is a schematic cross-sectional view of the switch shown in FIGURE 1 in its off position.

FIGURE 5 is a schematic cross-sectional view of the switch in FIGURE 4 immediately after said switch has taken along the been turned to its on position.

FIGURE 6 is a schematic cross-sectional view of the switch in FIGURE 4 in its on position.

FIGURE 7 is a schematic cross-sectional view of the switch in FIGURE 4 immediately after being rotated to its off position.

FIGURE 8 is a partial cross-sectional view of another embodiment of the present invention.

FIGURE 9 is a cross-sectional view of still another embodiment of the present invention.

FIGURE 10 is a cross-sectional view lines 10-10-in FIGURE 9.

FIGURE 11 is an exploded view of the embodiment shown in FIGURE 9.

FIGURE 12 is a schematic cross-sectional view of the switch in FIGURE 9 in its on position.

FIGURE13 is a schematic cross-sectional view of the switch in FIGURE 9 immediately after being rotated to its off position.

FIGURE 14 is a schematic -cross-sectional view of the taken along the i switch in FIGURE 9 in its off position.

FIGURE 15 is a schematic cross-sectional view of the switch in FIGURE 9 immediately after being rotated to its on position.

Referring to the drawings in detail, wherein like numerals indicate like elements, there is shown in FIGURE 1 a mercury time delay switch designated generally as 10.

Switch 10 comprises a cylindrical housing 12 having the housing 12 into two substantially identical chambers. The partition '18 is provided with a hole 20 adjacent its bottom edge so that mercury may flow from one chamber through the hole 20 into the other chamber as the switch 10 is manipulated between its oh and on positions.

The partition 18 is preferably provided with spaced

pockets

22 and 24 on one side thereof. As shown in FIG- URES 1 through 7, the

pockets

22 and 24 are disposed within the partition 18 on opposite sides of the hole 20.

However, it will be understood by those skilled in the art that the

pockets

22 and 24 may be provided by securing U-shaped channel members on one side of the partition 18. Shields 26 are provided on opposite sides of the partition 18 adjacent the uppermost surface of the partition 18. The shields 26 serve a purpose to be described hereinafter. A partially tapered hole 28 extends through the partition 18 within the confines of the shields 26. A valve member having a tapered seating portion for cooperation with the tapered portion of hole 28 is provided within the housing 12.

As seen more clearly in FIGURES 1 and 4 through 7, end wall 14 is provided with a flexible portion 32. Flexible portion 32 may be a flexiblediaphragm or bellows. The valve member 30 is fixedly secured to the inner surface of the flexible portion 32. The periphery of the flexible portion 32 is fixedly secured to the housing 12 and the end wall 14 so as to preclude leakage. A pair of electrodes 34 extend through the end wall 16 and have their ends disposed in one of the

pockets

22 and 24 as shown more clearly in FIGURES 1 and 2.

A plate 36 is fixedly secured to the lowermost peripheral surface of the housing 12 and extends outwardly to one side of the housing 12 in an axial direction. An L- shaped bracket 38 has one arm thereof fixedly secured to the plate 36 in any conventional manner such as by the screws 40. The other arm of the L-shaped bracket 38 is provided with a threaded hole through which extends the threaded member 42. The said other arm of the L-shaped bracket 38 is substantially parallel to the end wall 14 and the threaded member 42 is substantially coaxial with the valve member 30.

The flexible portion 32 is preferably concave when the tapered portion on the valve member 30 cooperates with the tapered portion on the hole 28 to preclude flow through said hole 28. One end of the threaded member 42 abuttingly engages the outer surface of the flexible portion 32 and maintains the valve member 30 in a closed disposition. The valve member 30 is movable to an open position by rotation of the threaded member 42. Since the flexible portion 32 is concave in the closed position of the valve member 30, the threaded member 42 need not be fixedly secured to the flexible portion 32 and the resiliency of the flexible portion 32 moves the valve member 30 from a closed position to an open postion. The extent of the open position of the valve member is determined by the position of the threaded member 42.

The mercury and other liquids are admitted to the interior of the housing 12 through a hole in said housing. After the mercury and other liquids have been admitted into the housing 12, the hole is then permanently sealed by a sealing cap 44. A plurality of means may be used to close the hole for admitting mercury and other liquids to the housing 12, the sealing cap 44 is shown solely for illustrative purposes. Thus, it will be seen that the switch comprises a sealed housing 12 having a valve member therein capable of being operated from outside of said housing 12 without piercing the walls of said housing 12. Thus, there are no moving parts extending through the wall of the housing 12 which are subject to leakage. Also, when the switch 10 has been assembled, the movable liquids are permanently sealed therein and yet the switch 10 is capable of having a variable time delay.

The housing 12 is supported by a U-shaped support 46 having substantially upright arms 48. A boss 50 is fixedly secured to the periphery of the housing 12 on one side thereof. A pin 52 extends in a radial direction from the boss 50 and is rotatably mounted in one of the arms 48. A boss 54 is fixedly secured to the periphery of housing 12 diagonally opposite to the boss 50. A pin 56 extends from the boss 54 in a radial direction and is rotatably supported by the other arm 48. A knob 58 is fixedly secured to the free end of the pin 56.

As seen more clearly in FIGURES 2 and 3, the knob 58 is provided with a pointer 59 which is capable of cooperating with suitable indicia so as to indicate whether the switch 10 is in its off or on position. For purposes of illustration, the indicia has not been illustrated in FIGURES 2 and 3 since the indicia would conceal other features of the switch 10. The

pins

52 and 56 are coincident with the partition 18. Since the boss 54 and pin 56 are fixedly secured to the housing 12, the housing 12 is rotatable about a radial axis by rotation of the knob 58. Rotation of the knob 58 is the means for opening or closing the switch 10 as will be made clear hereinafter.

As shown more clearly in FIGURES 4 through 7, the housing 12 is partially filled with mercury 60. The remainder of the housing 12 is substantially filled with a liquid, such as oil 62. The interface between the oil 62 and the mercury 60 is shown at 64. Thus, it will be seen that the amount of mercury 60 is substantially less than the amount of oil 62. Any suitable liquid may be used so long as the liquid is lighter than the mercury 60. Preferably, the amount of mercury 60 and oil 62 is less than the volume of the housing 12 thereby defining an air space 66 for permitting expansion and contraction due to temperature changes.

In FIGURE 4, the switch 10 is shown in its off position. The mercury 60 is disposed to one side of the partition 18 while the oil 62 is disposed on both sides of the partition 18. A small amount of mercury will be present within the

pockets

22 and 24, however the electrodes 34 are spaced apart so the switch 10 is in an off position.

When the switch 10 is rotated to an on position, the mercury within the

cavities

22 and 24 immediately flows to the lower right hand corner of the housing 12 thereby closing the switch 10 without a delay as shown in FIG- URE 5. The mercury 60 flows through the hole 20 from the left hand side of the partition 18 to the right hand side and occupies a position as shown in FIGURE 6. The rate of flow of mercury through the hole 20 depends on the position of the valve member 30. The mercury 60 cannot flow through the hole 20 at a rate faster than the rate of flow of oil 62 through the hole 28. Since the valve member 30 is provided with a tapered seat engaging end, and since the hole 28 is provided with a tapered seat portion, the rate of flow of oil 62 through the hole 28 can be accurately controlled so as to provide a time delay greater than ten minutes if desired. 7

If the switch 10 is rotated to an off position as shown in FIGURE 4, the relative position of the oil 62 and mercury 60 is shown in FIGURE 7 immediately after the switch 10 has been rotated to its off position. It will be noted that the mercury 60 will flow through the hole 20 to the chamber on the left hand side of the partition 18 with the same time delay.

Thus, it will be seen that the switch 10 has an instant on position and a time delay between the rotating of the switch 10 to its off position and the opening of the switch 10. By varying the size of the opening between the hole 28 and the valve member 30, and by varying the size of the hole 20, the time delay could last for more than thirty minutes. As a practical matter, a number of hours in delay time may be obtained. Since the valve member 30 is fixedly secured to the flxible portion 32, and since the position of the flexible portion can be varied by manipulation of the threaded member 42, the length of time delay may be varied to suit any particular purpose.

FIGURE 8 discloses a second embodiment of the present invention, designated generally 10'. The switch 10' is substantially identical with the switch 10. The size of the opening 20 in the switch 10 controls the rate of flow of the mercury in conjunction with the rate of flow of the oil 62. In a switch, such as switch 10, there is a limit to the minimum size of the opening 20 since the surface tension of mercury prevents flow when the hole approaches a diameter of 0.020 inch. If suflicient head is put on the mercury, mercury can be forced to flow through a smaller hole. However, there are limits to the size of the head which can be produced, and the provision of a mercury head requires more space and a larger amount of mercury. The mercury switches of the present invention are designed so as to have a length from less than one inch to a length of several inches. Thus, it will be seen that the provision of a mercury head is impractical in a switch such as switch 10.

The switch comprises a housing 12 having an end wall 16' corresponding to the structure shown in FIG- URES 1 through 7. In place of the partition 18 in switch 10, switch 10 is provided with a partition 18'. As seen more clearly in FIGURE 8, the housing 12 is provided with a well 70 juxtaposed to the partition 18 and having a width greater than the width of partition 18'. The partition 18' is provided with a hole 20 adjacent its lowermost edge within the well 70.

In the switch 10', suiflcient mercury 60 is provided so that mercury 60 is in the well 70 on both sides of the partition 18'. Since there is always some mercury on both sides of the partition 18, there is no meniscus at the hole 20', therefore there is no minimum size for the hole 20. Thus, it is possible to increase the time delay in the switch 10 'over the time delay in the switch. 10.

The amount of mercury 60 in the switch 10 as shown in FIGURE 8, is substantially the minim-um amount of mercury needed for the switch 10'. It will be noted that the mercury 60 in FIGURE 8 is divided into two parts separated by the surface area 72. Since the surface area 72 is relatively large, there is no meniscus present to interfere with the flow of the mercury.

It will be understood that switch 10' is substantially identical in all other respects with the switch 10.

FIGURES 9 through disclose still another embodiment of the present invention designated generally as 76. The switch 76 comprises a cylindrical housing 78 having

end walls

80 and 82.

The end wall 80 is provided with a radially extending flange 84. The radially extending flange 84 cooperates with a face plate 86 for mounting the switch 76 on a substantially upright wall 90. The face plate 86 is provided with a central hole therethrough through which the housing 78 extends. The face plate 86 is provided with a plurality of holes 88 for suitable mounting elements such as nails or screws for securing the face plate 86 to the wall 90.

The housing 78 is divided into two substantially identical chambers by an axially extending partition 92. The partition 92 is provided with a hole 94 adjacent its lowermost surface at one end thereof. Since the housing 78 rotates about its longitudinal axis which is substantially perpendicular'to the wall 90, the partition 92 is coincident with the axis of rotation.

As seen more clearly in FIGURES 9 and 11, the end wall 82 is provided wtih a flexible portion 96. An inner housing 98 is supported by the partition 92. The inner housing 98 is substantially coextensive with the flexible portion 96.

The inner housing 98 comprises a bottom wall 100 extending from either side of the partition 92 and substantially perpendicular thereto. Upright walls 102 extend from the bottom wall 100 to the housing 78. A rear wall 104 extends upwardly from the bottom wall 100 to the housing 78 and is substantially perpendicular to the

walls

100 and 102.

As seen more clearly in FIGURES 9 and 10, the partition 92 is provided with a V-shaped notch 106. A hole 108 is provided in the rear wall 104 coextensive with the V-shaped notch 106.

A valve member 110* is positioned within the housing 98 and is provided with an end 112 fixedly secured to the inner surface of the flexible portion 96. The other end 114 of the valve member 110 is tapered and cooperates with the V-shaped notch 106 on the partition 92 to control the flow of a liquid, such as oil, from one side of the partition '92 to the other side thereof. A bracket 116 is fixedly secured to a convenient surface such as wall 82. A threaded member 118 extends through a threaded hole in the bracket 116. One end of the threaded member 118 abuts the flexible portion 96 in the region of the end 112 of the valve member 110. The liquids are admitted to the housing 78 through a hole in the end wall 80. The hole in the end wall is then closed by any means such as by a sealing cap 120 which is shown solely for illustrative purposes.

Electrodes 122 extend through the end wall 82 as shown more clearly in FIGURE 11. The electrodes 122 are substantially parallel to one another and extend through the end wall 82 in such a manner that said electrodes are on the same side of the partition 92.

The inner housing 98 is provided so as to prevent contact between the oil 62 and the flexible portion 96. Since the flexible portion 96 has a plurality of positions, the switch 76 would be inaccurate if the flexible portion 96 were permited to contact the oil 62. Also, the flexible portion 96 need not be oil-resistant. It will be noted that the rear wall 104 is substantially thicker than the other walls in the switch 76 so that the valve member can extend through the hole 108 so as to preclude the entry of oil into the inner housing 98 and at the same time cooperate with the V-shaped notch 106 to control the flow of the oil 62.

FIGURES 12 through 15 are schematic end views disclosing the operative positions of the switch 76. For purposes of illustration, the end wall 82 and the flexible portion 96 are not shown in FIGURES 12 through 15. FIGURE 12 shows the switch 76 in its on position. In FIGURE 12, it will be noted that suflicient mercury 60 is provided so that the electrodes 122 are bridged thereby.

FIGURE 13 discloses the switch 76 immediately after the housing 78 has been rotated about its longitudinal axis to an off position. It will be noted that the switch 76 has substantially no delay time between its on and oif position. FIGURE 14 discloses the switch 76 in its off position a short interval of time later after the mercury has reached same level in both chambers. It will be noted that the mercury 60 is present in a suflicient quantity so that the mercury is on both sides of the partition 92. Thus, the hole 94 has no minimum dimension since there is no meniscus at the hole 94.

FIGURE 15 discloses the switch 76 immediately after being manipulated from an 011 position to an on position. It will be noted that a substantial delay is provided between the time the switch 76 is manipulated to its on position and the moment that the electrodes 122 are bridged by the mercury 60. Thus, the switch 76 is an instant off switch and delay on switch.

The flow of the mercury 60 is dependent on the rate of flow of the oil 62 due to the size of the flow passage between the tapered end 114 on the valve member 110 and the V-shaped notch 106 in the partition 92. The switch 76 is provided with an air space 66 above the oil 62 in the same manner as set forth above.

While each of the

switches

10, 10 and 76 have been provided with a valved hole in a central partition, it will be appreciated that a hole may be provided in the partition which is not valved. In this case, the time delay would not be variable. While each of the

switches

10, 10" and 76 have been disclosed as having oil above the mercury, it will be appreciated that any liquid lighter than mercury may be substituted therefor.- Furthermore, it will be obvious to those skilled in the art that the valve member and the aperture or hole in the partition may be eliminated, thereby relying solely on the control of the flow of mercury for the time delay.

In each of the

switches

10, 10' and 76, the oil and the mercury are permanently sealed within the housing of the switches. The valve member on each of said switches is contained wholely within the housing, therefore the external wall of the housing is not pierced thereby providing a possibility for leakage. In each of the above switches, the electrodes are on the same side of the partition and the housings are rotatable about an axis coincident with the partition which divides the housings into substantially identical chambers. In each of the above switches, the time delay is capable of being varied at will. In switches and 76, the size of the hole in the partition has no minimum limit.

The housing 98 may be filled'with oil 62 if desired. An oil-resistant flexible portion 96 would be required. Also, the valve member 110 would not require a rubbingfit 'with the hole 108. Since the valving action of the oil takes place at the V-shaped notch 106, the presence of oil within housing 98 will not interfere with the metering of the oil.

The shields 26 permit the housing 12 to tilt to a greater degree. Therefore, the switch 10 may have a greater time delay since a larger amount of mercury may be provided without having the mercury flowing through hole 28.

The electrodes-need not be positioned near the internal periphery of the housing 12. The time delay of switch 76 can be increased by raising the level of the electrodes. In addition, the electrodes 34 may extend through either end wall of the housing 12. Alternatively, one of the electrodes could extend through the end wall 16 while the other electrode extends through the wall of housing 12. In this case, only the electrode extending through the wall 16 would extend to the pockets in the partition. Alternatively, one of the electrodes in switch 10' could extend through the wall of the well 70 in which mercury is always present. Since the mercury in the pocket 24 is spaced from the mercury in the well 70, there is no possibility of the switch 10' being on in all positions of the housing 12'.

If the

pockets

22 and 24 in the switch 10 were eliminated, the switch 10 would have a delay period when manipulated to either the on or off position.

While the means for varying the position of the flexible portion in the

switches

10, 10 and 76 has been shown as a threaded member extending through a bracket, it will be appreciated that other mechanical means may be substituted therefor. For example, a cam or a pivoted lever may be substituted for the threaded members on the

switches

10, 10 and 76. Since all of the elements of the

switches

10, 10' and 76 are contained within the housing of said switches except for the threaded members, the switches are simple, easy to manufacture and have a long life.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two substantially identical chambers, a hole in said partition adjacent a bottom edge of said partition, mercury partially filling said housing, means for rotatably mounting said housing for causing said mercury to flow through said hole from one chamber to another, and a pair of electrodes in one of said chambers on the same side of said partition, said electrodes being spaced apart so as to be bridged by said mercury when said mercury is in said one chamber, said partition having a second hole which is located in a plane higher than the plane of said first-men-' tioned hole, a fluid lighter than mercury substantially filling the remainder of said chambers, and a selectively operable valve means for controlling the flow of the fluid through said second hole in said partition thereby controlling the time delay of the bridging of said electrodes by said mercury.

2. A mercury time delay switch in accordance with claim 1 including a shield on said partition, said shield being disposed between said holes in said partition.

3. A mercury time delay switch in accordance with claim 1 wherein said valve means includes a valve member disposed within one of said chambers and selectively movable toward and away from said second hole to control flow of said liquid through said second hole.

4. A mercury time delay switch in accordance with claim 1 including a flexible portion on a wall of said housing, said valve means including a valve member extending between said flexible portion and said partition, and mechanical means outside of said housing for selectively moving said flexible portion thereby moving said valve member relative to said partition.

5. A mercury time delay switch in accordance with claim 4 wherein said housing is cylindrical and said flexible portion is a portion of an end wall of said housing.

.6. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two substantially identical chambers, said partition having a hole therethrough adjacent the bottom edge thereof, mercury partially filling said housing, means for rotatably mounting said housing for causing said mercury to flow through said hole from one chamber to another, a pair of electrodes in one of said chambers on the same side of said partition, said electrodes being spaced apart so as to be bridged by said mercury when said mercury is in said one chamber, spaced pockets on one side of said partition, each one of said electrodes having an end thereof positioned in one of said pockets said pockets being of sufficient size so as to retain an amount of mercury capable of bridging said electrodes immediately after movement of said housing to an on position.

7. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two substantially identical chambers, said partition having a hole therethrough adjacent the bottom edge thereof, mercury partially filling said housing, means for rotatably mounting said housing for causing said mercury to flow through said hole from one chamber to another, a pair of electrodes in one of said chambers on the same side of said partition, said electrodes being space-d apart so as to be bridged by said mercury when said mercury is in said one chamber, a well in said housing, said hole extending through a portion of said partition positioned in said well, the mercury in said housing being also positioned in said well, and the level of the mercury in said well being above said hole in all positions of said housing.

8. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two substantially identical chambers, a hole in said partition adjacent the bottom edge of said partition, mercury partially filling said housing, means for rotatably mounting said housing for causing said mercury to flow through said one hole from said one chamber to another, a pair of electrodes in one of said chambers on the same side of said partition, said electrodes being spaced apart so as to be bridged by said mercury when said mercury is in said one chamber, said partition having a second hole which is located in a plane higher than the plane of said first-mentioned hole, a fluid lighter than mercury substantially filling the remainder of said chambers, a selectively operable valve means for controlling the flow of fluid through said second hole in said partition thereby controlling the time delay of the bridging of said electrodes by said mercury, a flexible portion on a wall of said housing, said valve means including a valve member extending between said flexible portion and said partition, mechanical means outside of said housing for selectively moving said flexible portion thereby moving said valve member relative to said partition, said housing being cylindrical in shape, said flexible portion being a portion of an end wall of said housing, a well in said housing, said hole extending through a portion of said partition disposed within said well, the mercury in said housing being also disposed within said well, and the level of the mercury in said well being above said hole on both sides of said partition in all positions of said housing.

9. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two substantially identical chambers, a hole in said partition adjacent a bottom edge of said partition, mercury partially filling said housing, means for rotatably mounting said housing for causing said mercury to flow though said hole from one chamber to another, a pair of electrodes in one of said chambers on the same side of said partition, said electrodes being spaced apart so as to be :bridged by said mercury when said mercury is in said one chamber, said means for rototably mounting said housing enabling said housing to rotate about an axis coincident with said partition, said axis being the longitudinal axis of said housing, and a valve member extending to a V-shaped notch in said partition, said valve member cooperating with said notch to control the flow of a liquid lighter than said mercury disposed within said housing in said chamhers.

10. A mercury time delay switch in accordance with claim 9 including a wall within said housing substantially perpendicular to said parition, said valve member extending through a hole in said wall, said wall being positioned between said notch and an end wall of said housing.

v11. A mercury time delay switch in accordance with claim 10 wherein a portion of said end wall is flexible, said valve member being fixed to an inside surface of said flexible portion, and a mechanical means outside of said housing for selectively moving said flexible portion thereby causing relative movement between said valve member and said notch.

12. A mercury time delay switch in accordance with claim 11 including a face plate for rotatably mounting said housing, said face plate cooperating with a flange on the other end wall of said housing for mounting said housing to an upright wall.

13. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two substantially identical chambers, a hole in said partition adjacent a bottom edge of said partition, mercury partially filling said housing, means for rotatably mounting said housing for causing said mercury to flow through said hole from one chamber to another, a pair of electrodes in one of said chambers on the same side of said partition, spaced pockets in said housing on said one side of said partition, each of said electrodes having an end thereof positioned in one of said pockets, at well in said housing, said hole extending through a portion of said partition disposed within said well, said mercury being in said well above said hole on both sides of said partition in all positions of said housing.

14. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two chambers, a hole in said partition adjacent a bottom edge of said partition, mercury partially filling said housing, means mounting said housing for rotation about an axis coincident with said partition for causing said mercury to flow through said hole from one chamber to another, a pair of electrodes in one of said chambers on the same side of said partition, and spaced pockets in said one chamber, each one of said electrodes having an end thereof positioned in one of said pockets.

15. A mercury time delay switch comprising a sealed housing, a partition dividing said housing into two chambers, a hole in said partition adjacent a bottom edge of said partition, mercury partially filling said housing, means mounting said housing for rotation about an axis coincident with said partition for causing said mercury to flow through said hole from one chamber to another, a pair of electrodes in one of said chambers on the same side of said partition, spaced pockets in said one chamber, each one of said electrodes having an end thereof positioned in one of said pockets, a well in said housing, said hole extending through a portion of said partition disposed within said well, the mercury in said housing extending into said well and being above said hole on both sides of said partition in all positions of said housing.

16. In a mercury delay time switch having a housing divided into two chambers, and mercury partially filling said housing for flow through a hole in said partition from one chamber to another, the improvement comprising a well on said housing, said hole extending through a portion of said partition disposed within said well, the mercury in said housing being also disposed within said well, and the level of the mercury in said well being above said hole on both sides of said partition in all positions of said housing.

-17. In a mercury time delay switch having a housing divided by a partition into two chambers, mercury partially filling said housing, a hole in said partition for permitting the mercury to flow from one chamber to another, a pair of electrodes in one chamber only, the improvement comprising pockets in said one chamber, each of said electrodes having an end thereof positioned in one of said pockets, whereby a time delay is provided when said housing is moved to an off position only.

18. A mercury time delay switch having a housing divided into two chambers by a partition, a hole in said partition adjacent a bottom edge thereof, mercury partially filling said housing for flowing through said hole from one chamber to another, the improvement comprising the partition being in a plane substantially perpendicular to the longitudinal axis of said housing, a second hole in said partition in a plane higher than the plane of said first hole, a valve member :for cooperation with said second hole, said valve member being fixedly secured to the inner surface of a flexible portion of an end wall of said housing, a pair of electrodes on one side of said partition, and a fluid substantially filling said housing and being lighter than mercury.

19. A mercury time delay switch in accordance with claim 3 wherein the longitudinal axis of said valve member is substantially coincident with the plane of said partition.

20. A mercury time delay switch comprising a housing divided by a partition into two chambers, mercury partially filling said housing, a hole in said partition for permitting the mercury to flow from one chamber to another, a second hole in said partition for permitting the fluid in said housing above said mercury to flow from one chamber to another, a pair of electrodes in one chamher only, means for moving said housing between an otf position and an on position, said mercury being in said one chamber in the on position of said housing, and means in said one chamber for retaining a portion of said mercury therein when said housing is in the oif position, said means retaining said portion of said mercury so that such electrodes are not bridged by said portion of said mercury, and said portion of said mercury being suflicient to bridge said electrodes when said housing is in its on position.

21. A time delay switch comprising a housing, a partition for dividing the housing into two sections, an electrically conducting fluid within one of said sections, a second nonconducting fluid lighter than said electrically conducting fluid filling the rest of said housing, said p-artition having holes therethrough, said housing being rotatable, -a pair of electrical connectors within one of said sections, said electrically conducting fluid having suflicient volume to bridge said connectors in one position of said housing, the flow of said second fluid through said partition holes controlling the flow of said electrically conducting fluid.

22. A time delay electrical switch comprising: a pivotable capsule having two compartments separated by a wall, said compartments having a conductive liquid therein; an unrestricted conductive liquid passage in the normally lower end of said wall and an adjust-able metering passage in the normally upper end of said wall whereby the flow of conductive liquid bet-ween compartments is controlled by said metering passage in the passage of fluid between compartments; and electrodes in at least one compartment adaptable to be bridged by said conductive 1 1 liquid, said electrodes being connected through said capsule.

23. A time delay electrical switch comprising: a pivotable capsule having two fluid compartments therein separated by a wall; a pair of electrodes in at least one of said compartments, each electrode extending through the capsule to the exterior; an electrically conductive liquid in said compartment; an unrestricted communicating passage near the bottom of said Wall between said compartments to permit free flow of said conductive liquid therebetween; and an adjustable metering passage connecting said fluid compartments at the top of said wall for metering fluid tending to be displaced by said conductive liquid whereby flow of said conductive liquid between compartments is controlled by said fluid through said metering passage.

24. A time delay switch as set forth in claim 23 wherein said electrically conductive liquid is mercury.

25. A time delay flow control of mercury comprising: a hermetically sealed vessel containing a charge of mercury; a partition separating said vessel into two compartments, said vessel being rockable with said partition nutatable about a vertical plane; a passage through said partition at the lower end thereof of a size no larger than to permit the free flow of said mercury therethrough, and an adjustable metering passage at the top end of said 12 partition to change the cross-sectional area of said metering passage to meter the fluid between said compartments tending to be displaced by said flow of mercury between said compartments upon said vessel being rocked whereby mercury flow is delayed in accordance with the metering of fluid betweentcompartrnents.

References Cited UNITED STATES PATENTS 1,374,571 4/1921 Hummel 2514-335 2,644,866 7/1953 Turnupseed et a1. 200-33 2,831,077 4/1958 Salyer 20033 2,851,547 9/1958 Hartz 20033 3,003,044 10/1961 Davis et a1. 200-33 FOREIGN PATENTS 100,179 1/ 1937 Australia.

ROBERT K. SCHAEFER, Primary Examiner.

R. M. WOOD, M. LEVY, E. J. SAX, B. A. GILHEANY,

Examiners.

ROBERT S. MACON, S. B. SMITH, Assistant Examiners.

Claims

1. A MERCURY TIME DELAY SWITCH COMPRISING A SEALED HOUSING, A PARTITION DIVIDING SAID HOUSING INTO TWO SUBSTANTIALLY IDENTICAL CHAMBERS, A HOLE IN SAID PARTITION ADJACENT A BOTTOM EDGE OF SAID PARTITION, MERCURY PARTIALLY FILLING SAID HOUSING, MEANS FOR ROTATABLY MOUNTING SAID HOUSING FOR CAUSING SAID MERCURY TO FLOW THROUGH SAID HOLE FROM ONE CHAMBER TO ANOTHER, AND A PAIR OF ELECTRODES IN ONE OF SAID CHAMBERS ON THE SAME SIDE OF SAID PARTITION, SAID ELECTRODES BEING SPACED APART SO AS TO BE BRIDGED BY SAID MERCURY WHEN SAID MERCURY IS IN SAID ONE CHAMBER, SAID PARTITION HAVING A SECOND HOLE WHICH IS