US2215788A - Switch - Google Patents

Description

Sept. 24, 1940.

J. w. HAMILTON ET AL 2,215,788

SWITCH Filed June 9, 1938 2 Sheets-Sheet l F 1 Z. 55 R5 55 JOE /L JOHN K. ASDER BY ZZ ATTORNEYS Sept. 24, 1940. J. w. HAMILTON ET A1. 2,215,733

SWITCH Filed June 9, 1938 2 Sheets-Sheet 2 INVENTORS J05 WHAM/L TON JgH/v K. ASDER 36 ATTORNEYS Patented Sept. 24, 1940- UNITED STATES PATENT OFFICE I 2,215,788 swrrcn Joe W. Hamilton and John K. Asder, Los Angeles, Calif.

' This invention relates to a delayed action switchand refers more particularly to a time delay action electric switch suitable for light and other circuits.

This type of switch allows a person to manually actuate the switch, for example, to extinguish lights, but these will remain illuminated for, av

predetermined time period to enable the user to leave the premises while the lights are still on.

Switches of this type employ a thermostat of bi-metallic type having a heating coil which is usually in shunt with the main circuit; however, when the switch is thrown manually to the oil position, the circuit of the heating coil is placed in series with the load, so that the coil operates as a part of the current path through the load circuit. This arrangement has the drawback-that when the load is changed, the total resistance changes. If the load resistance is reduced materially, the current flow rises proportionately. And if this practice is carried too far, the heating coil will usually burn out, or not be heated at all. Consequently, switches of this character are limited to their specific loads. For

example, practical experiments have shown that a'switch designed to give a two-minute delay a with a 40-watt load would have approximately a one-minute delay with a Gil-watt load, a halfminute delay-with 75 watts, and proportionally less time as the load increased until at about 250 watts the heating coil of the switch would burn in two. I

An object of the present invention is the provision of a delayed action switch which will operate uniformly and without any variations in the time period of the delayed action irrespective of the magnitude of the load in the main circuit.

Another object is the provision of a delayed action switch capable of carrying anyload which its main line contacts can carry.

Other objects of the present invention will be apparent in the course of the following specifica- .tion.

The objects of the present invention may be realized by arranging the heating element of the thermostat in a multiple circuit relationship with the load, so that the heating element can work concurrently with but independently of the load. The heating element is, therefore, so construct .ed that it canbe placed across thesupply line independently of any other device or circuit.

The invention wilLappear' more clearly from the following detailed description when taken in connection with the accompanying drawings,

showing by way of example a preferred embodiment of the inventive idea.

In the drawings:

Figure 1 shows in rear elevation a switch constructed in accordance with the principles of the 5 present invention;

Figure 2 is a section along the line 2-2 of Figure 1;

Figure 3 is a section along the line 3-4 of Figure I; 10

Figure 4 is a perspective view of the switch in its of! position;

Figure 5 is a diagram showing the electrical connections of the switch in the 012 position;

Figure 6 is similar to Figure 4 and shows the II switch in its on position;

Figure 7 is a section similar to 'Fig. 2 and shows the switch in its on position;

Figure 8 is a diagram similar to that of Figure 5 and shows the circuit in the on position of the :0 switch;

Figure 9 is similar to Figures 4 and 6 and shows the switch in its intermediate position with the heating coil of the thermostat included in its circuit; 1 25 Figure 10 is a section similar to Figs. 2 and '7 and shows the switch in its intermediate position; and

Figure 11 is a diagram similar to those shown in Figures 5 and 8 and illustrates the circuits at a time when the heating coil of the thermostat is energized by the electrical current.

The switch shown in the drawings may be conveniently aflixed to a wall and comprises a switch box or casing having a front wall l5, side walls It and H, the top l8 and the bottom or base l9. This switch box is made of 'an insulating material such as Bakelite, porcelain or the like.

The front wall l5 has an opening 20 through i which the finger-operated insulating lever 2| extends. The lever 2| has an inner round portion 22 which is rotatable along with its axis 23 mounted in the walls l6 and I1. vAn extension arm 24 is securely attached to the portion 22 of the finger lever 2i and carries apivot pin 25. A fork 26 embraces the pivot pin 25 and is connected with one end of a coil spring 21, the opposite end of which surrounds an innerprojection 28 of a yoke or swinging member 28. 60

' The yoke or swinging member 29 is rotatable along with its axis III which extends through the side wall It and member 41 of the switch box. The yoke 29 comprises two side bars II and 32 which are interconnected by a transverse bar or circuit-closer bar 33. This is the arrangement for giving an automatic, quick movement to the frame or yoke 29 when the finger-operated lever 2| is moved from the open circuit position or off position, shown in Figures 1 to 5', to the on position or the closed circuit position, shown in Figures 6 to 8.

An insulated wire 34 is connected with a plus terminal 35 carried by the top l8 of the casing. The minus terminal is connected with the wire 35 and is carried by the bottom |9 of the casing. The terminal 35 constitutes an end element common to the two circuits 51 and 58 (Fig. 5).

The terminal 35 is connected by means. of a wire 38 with the device 39, which is illustrated diagrammatically in the drawings and which constitutes the load of the main circuit; it may be a lamp or a series of lamps, a heating device, or any other consumer of electrical energy. Hereinafter it will be referred to as the lamp 39.

A wire 49 connects the lamp 39 with another terminal 4! situated upon the top l8 of the casing. The terminal 4| is electrically connected with a strip 42 integral with the Ushaped contact 43, which is also a conductor of electricity. The contact 43 comprises an upwardly extending portion 44 provided with a bent end 45, and constitutes an end 'element of the load circuit. As shown in Figures 6 and 9, the bar 3| of the swinging yoke 29 is adapted to engage the portion 44 rangement, an electrical connection is established between the yoke 29, and the L-shaped member 41, and the minus terminal 31.

A wire 48 is connected to the terminal bolt 49, constituting a part of the plus terminal 35. The opposite end of the wire 48 constitutes the heating coil 55 of the bimetallic strip 5|. The opposite end of the heating coil 55 is connected to the terminal 53 carried upon the top l8 of the casing.

A tongue or contact 54, which is provided with a curved portion 55, is situated within the casing,

and is electrically connected with the terminal 53 (Figs. 2, 7 and 10). An' insulatingblock 55 is used to support the tongue 54 in its proper position within the casing. The member 54 constitutes an end element of the thermostat circult 58.

An electrical connection is maintained between the tongue or the strip 54, which may be engaged by the transverse bar 33 of the swinging member 29, and the heating coil 58, as well as the positive terminal 35 of the switch. I

The lower portion of the bimetallic strip 5| is provided with an insulating knob 51. which is adapted to engage the bent portion 58 of a double-armed lever 59, when the strip 5| is bent due to heating. The end portion 55 of the lever 59 is reciprocablein the direction toward and away from a block 5| constituting a part of the bottom l9 of the casing. A coil spring 52 engages the block 5|, while its opposite end surrounds the portion 55 and presses against the bent porin its vertical position, which is shown in the drawings.

The vertical arm 55 of the lever 59 is provided with a hook or .detent 55, which is adapted to engage the bar 32 of the swinging circuit closer 29 in the course of the return movement of the circuit closer 29 to its off position.

The operation of the device is as follows:

In the off position shown in Figures 1 to 4 of the drawings, the switch lever 2| is directed upwardly while the swinging circuit closer 29 also extends upwardly but is inclined in the opposite direction. As shown in Figure 2, the tongue 54 is out of engagement with the circuit closer 29, which is also out of engagement with the U- shaped contact 43. As shown in the diagram of Figure 5, in this position the load circuit 51 and the thermostat circuit 53 both remain open.

In order to close the switch, the operator pulls the lever 2| downwardlyso that it assumes the position shown in Figures 6 and '1. The lever turns along with its axis 23 and the rod 24 of the lever swings upwardly along with the pivot and the fork 25, which is engaged by the spring 21. Due to the pressure of the spring 21, the circuit closer 29 is rapidly swung in the opposite direction, with the result that the transverse bar 33 of the circuit closer 29 is moved downwardly into the position shown in Figures 6 and '1, in which his situated underneath the tongue 55. In the course of this swinging movement of the circuit closer 29, the bar 32 slides along the inclined surface 59 of the hook 55, while the transverse bar'33 slides along the tongue 54. However, in the end position shown in Figures '6 and 7, the hook 55 is situated above the transverse bar 33 which is also out of engagement with the tongue 54.

As shown in Figure 8, in this position of the switch a circuit is established between the positive terminal and the negative terminal 31.

The alternating electrical current will flow through he wire 34, the terminal 35, the lamp 39, the connecting piece 42, the U-shaped contact 43, the circuit closer 29, the L-shaped member 41, the bolt 45, the terminal 31, and the wire 35. However, in this on position of the switch, the thermostat is not included in an electrical circuit. g

If now the user desires to turn oi! the switch, he swings the lever 2| upwardly until it is moved into the position shown in Figures 9 and 10 of the drawings. Due to the described connections, the circuit closer 29 will also tend to swing upwardly and the transverse bar 33 will slide along the lever 59 until it' is brought into engagement with the hook and is stoppedby that hook. This position.- is shown in Figures 9 and 10. In this position the transverse bar 33 of the circuit closer 29 is in contact with the tongue 54. At the same time the side bar 3| oi the I the coil 55 will flow through the terminal 53 to the tongue 54, flowing from'the tongue 54 to the 1s circuit closer 29, the L-shaped member and the negative terminal 31.

. allytoward the wall I! sliding upon the underlying portion of the circuit closer 28 until finally the hook 66 will release the circuit closer 29. Them-under the action of the spring 21, the circuit closer will spring back from the position shown in Figures 9 and 10 to the off position shown in Figures 1 and 2 of the drawings. The engagement between the circuit closer I! on the one hand and the tongue ii and the U-shaped contact 43 on the other hand will be interrupted, so that no current will flow any more through the load circuit 61 or the thermostat circuit 88.

The bimetallic strip 5| will gradually cool and return to its original position, which is shown in the drawings, while at the same time the spring 82 will cause the lever 58 to return to its illustrated position.

Practical experience has shown that the period of time during which the current is caused to flow through the load circuit 61 after the lever- II has been switched to its off position, depends entirely on the construction of the switch and is unaffected by the size of the load 3!.

The switch may be so constructed that the circuit 61 is interrupted a few seconds to several minutes after the lever 2| has been switched 011'.

One of the important advantages of the present construction is that the thermostatic circuit 68 is operated while the load circuit 61 is intact, so that there are two individual, distinct and complete circuits in operation at one and the same time.

It is apparent that the specific illustration shown above has been given by way of illustration and not by way. of limitation, and that the structure above described is subject to wide variation and modification without departing from the scope or intent of the invention. For example, the switch may have the form of a pedant switch or a socket switch. All of such and other variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. In a switch, a terminal adapted to be connected to one pole of a source of electrical energy and to the main consumer of said electrical energy, another terminal adapted to be connected to said consumer of electrical energy, a third terminal adapted to be connected to the other pole. of said source of electrical energy, a circuit closer, an insulated toggle-type device engaging said circuit closer for swinging it backwards and forwards from an open circuit position to a closed circuit position and from the closed circuit position to the open circuit poation, insulated restraining means positioned to arrest said circuit closer in the course of its movement from the closed circuit position to the open circuit position in an intermediate position, a conducting member engaging said circuit closer in all positions of the latter and permanently connected with the third-mentioned terminal, a

single contact connected with the'second-mentioned terminal and operatively engaging said circuit closer in its closed circuit position and inits intermediate position to maintain a flow of electrical energy from said source through said main consumer while the circuit closer is in the closed circuit position and while it is moved from the closed circuit position to the intermediate position, a thermostat, means conductively connecting said thermostat with the first-mentioned terminal, a single contact conductively connected with said thermostat and contacting said circuit closer in said intermediate position, wherebysaid thermostat is connected with said source in parallel to said consumer in said intermediate position, and means actuated by said thermostat when the latter is heated by current of said source to disengage the restraining means and permit further movement of the circuit closer from the intermediate position to the open circuit position, the last-mentioned contact being formed to remain longer in engagement with the circuit-closer than the first-mentioned contact in the course of the movement of the circuitcloser from the intermediate position to the open circuit position, whereby the connection of said thermostat with said source is interrupted after the interruption of the connection of said consumer with said source.

2. In a switch, a terminal adapted to be connected to one pole of a source of electrical energy and to the main consumer of said electrical energy, 1 another terminal adapted to be connected to said consumer of electrical energy, a third terminal adapted to be connected to the other pole of said source of electrical energy, a conducting circuit-closing yoke having two sidebars, a transverse bar interconnecting said sidebars, and an axis connected with at least one of said side-bars; an insulated toggle-type device an open circuit position to a closed'circuit position and from the closed circuit position to the open circuit position, insulated restraining means positioned to engage one of the side bars of the yoke in the course of the movement of the yoke from the closed circuit position to the open circuit position and thereby arrest the yoke in an intermediate position, a conducting member engaging the axis of said yoke in all positions of the latter and permanently connected with the third-mentioned terminal, a single contact connected with the second-mentioned terminal and operatively engaging another side bar of the yoke in the closed circuit position and the intermediate position of the yoke to maintain a flow 0! electrical energy from said source through said main consumer while the yoke is in the closed circuit position and while it is moved from the closed circuit poistion to the intermediate position, ing said thermostat with the first mentioned terminal, a single contact conductively connected with said thermostat and-contacting the transverse bar of the yoke in said intermediate position, whereby said thermostat is connected with said source in parallel to said consumer in said intermediate position, and means actuated by said thermostat when the latter is heated by current of said source to disengage the restraining means and permit further movement of the yoke from the intermediate position to the open circuit position,

3. In a switch, a terminal adapted to be cona thermostat, means conductively connectpin embraced by said fork, a finger level connected with said pivot pin and movable to two diflerent positions to cause said pivot pin, said fork and said coil spring to swing said circuit closer from an open circuit position to a closed circuit position and from the closed circuit position to the open circuit position, insulated restraining means positionedto arrest said circuit closer in the course of its movement from the closed circuit position to the open circuit position in an'intermediate position, a conducting member engaging said circuit closer in all posi-- tions of the latter and permanently connected with the third-mentioned terminal, a single contact connected with the second-mentioned terminal and operatively engaging said circuitcloser in its closed circuit position and in its intermedate position to maintain a flow of electrical energy from said source through said main consumer while the circuit closer is in the closed circuit position and while it is moved from the closed circuit position to the intermediate position, a thermostat," means conductively connecting said thermostat with the first-mentioned terminal, a single contact conductively connected with said thermostat and contacting said circuit closer in said intermediate position, whereby said thermostat is connected with said source in parallel to said consumer in said intermediate position, and means actuated by said thermostat when the latter is heated by current of said source to disengage the restraining means and permit further movement of the circuit closer irom the intermediate position to the open circuit position.

7 4. In a switch, a terminal adapted to be connected to one pole of a source of electrical energy and to the main consumer of said electrical enopen circuit position in an intermediate position,

a conducting member engaging said circuit closer in all positions of the latter and permanently connected with the third-mentioned terminal, a single contact connected with the second-mentioned terminal and operatively engaging said circuit closer in its closed circuit position and in its intermediate position to maintain a flow of electrical energy from said source through said main consumer while the circuit closer is in the closed circuit position and while it is moved from the closed circuit position to the intermediate position, a bimetallic strip, a heating coil enclosing. said bimetallic strip and conductively connected with the first-mentioned terminal, a single contact conductively connected with said heating coil and contacting said circuitcloser in said intermediate position, whereby said heating coil is connected with said source in parallel to said consumer in said intermediate position, and insulated means movable by said bimetallic strip when the latter is heated by current of said source to swing said restraining lever and thereby permit further movement of the circuit closer from the intermediate position to the open circuit position.

JOE W. HAMILTON.

JOHN K. ASDER.

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