US1919385A - Circuit breaker - Google Patents

Description

July 25, 1933. R M STAFFORD 1,919,385

G IRCUIT BREAKER Filed June 23, 1930 2 Sheets-Sheet l Z5 INVENTOR stafiofi 1 c ATT o NEYfi f July 25, 1933. R. M. STAFFORD C IRCUIT BREAKER Filed June 23, 1930 2 Sheets-Sheet 2 @CQa/Jfi ATTORNEY5 HWENTOR {by M. :SLCL-fi BY 0 Patented July 25, 1933 UNITED STATES PATENT OFFICE ROY M. STAFFORD, OF BEAUMONT, TEXAS, Assrcnon To STAFFORD ELECTRIC GAUGE CORPORATION CIRCUIT BREAKER Application filed June 23,

My invention relates to fiuid level indicators by means of which the fluid. level in tan -3 or similar containersmay be read on an indicator at some distance from the tank. The present invention relates particularly to the circuit breaker positioned at the tank through which electrical impulses are transmitted to the distant indicator.

It is an object of my invention to construct a simple type of circuit breaker of this character which may-be positioned on the tank itself and connected with the tank in such manner that no leakage of gas from the tank may escape.

It is also an object to providea switch-opcrating mechanism which may be mounted in an oil bath for effective lubrication and in which there is no danger of a spark whereby the gas or oil may be ignited.

The device is intended particularly for use in oil tanks wherein petroleum is stored before use and the general purpose of the invention is to provide a circuit breaker for use with an indicator which may be housed in a small and compact casing and which will be particularly accurate and reliable in its action.

Referring to the drawings herewith, Fig. 1 illustrates a side view of my invention mounted upon the top of a tank with certain parts being shown in section for greater clearthe structure shown in my prior application for Patent No. 375,944, filed July 5, 1925, and co-pending herewith. The invention herein resides in the modification of the device set out in the prior application whereby '-.the' circuit breaker may be positioned directly upon the tankand wherein provision is made for preventing the escape of gas from said tank.

lVith reference particularly to Fig. 1, I have shown. the device as mounted upon the top or roof 1 of a sheet metal tank of the usual construction employed in oil storage work. The deviceis housed within an outer casing 2, the walls of which are made tight to form a containerfor oil shown at 3 there- 1930. Serial NO. 463,298.

in. The casing is mounted upon a short post or pedestal 4L secured to the upper wall of the container in any desired manner. The shape of the casing or container is formed to provide a shoulder 5 midway of the height of the casing upon which the frame 6 of the mechanism may be supported. The upper end of the tank is closed by a cover plate 7, through which I have provided openings to receive pipes 8 and 9 through which the controlling float and weight connections may pass.

The supporting frame 6 of my device is preferably a skeleton frame metal approximately rectangular in outline and shaped to fit within the casing. The structure of this frame will be understood more clearly from Mounted upon this frame intermediate the ends thereof is a cross shaft 10, which is supported for rotation upon the frame. 011 one end of the shaft is formed a toothed wheel or gear 11, the periphery of which is formed with teeth of the proper size to be engaged by an operating chain 12 shown in Fig. 1. This wheel is fixed to the shaft, which is adapted to rotate therewith.

Mounted on said frame and directly above the shaft 10 is a shaft 13, also rotatable on its bearings and operatively connected with the shaft 10 through a small gear 1 L thereon, mounted on said shaft13 and adapted to mesh with a, larger gear 15 on said shaft 10 and positioned between the wheel 11 and the inner frame member.

Mounted on the upper shaft 13 are two rotating wheels 16 and 17. These two wheels are loose upon the shaft and are ordinarily idle thereon. They may be connected for rotation with said shaft, one in one direction and the other in the opposite direction, by means ,of a ratchet and pawl arrangen'rent which will presently be described. Each of the wheels 16 and 17 have a wide groove cut in the periphery thereof and at spaced intervals along the said groove are transverse pins 18 adapted to contact with the lever arms 19 and 20 respectively.

Between thetwo wheels 16 and 17 is the disc 21, said disc being of materially smaller diameter than are the two wheels 16 and 17 and is fixed to the shaft so as torotate therewith. Each of the wheels 16 and 17 has an is formed into a ratchet wheel having teeth 24 thereon adapted to be engaged by a pawl upon the disc 21. Said pawl engages the ratchet in such manner as to cause the movement of the hub and the adjacent wheel when said disc is rotated in one direction. The opposite wheel is engaged by a similar pawl 24 and this pawl is so, arranged as to allow the rotation of the other wheel, but in an opposite direction to that of the first wheel. In this manner the rotation of the shaft 13 and the disc 21 in one direction will rotate the wheel 16. The rotation of the shaft and disc in the opposite direction will rotate the wheel 17.

Each of the wheels is held against rotation in a direction opposite to the one in which it is turned through the shaft 13 by a pawl 25 engaging with a ratchet 26 on the hub 22, the arrangement of the pawl 25 being shown best in dotted lines in Fig. 3, and it will be Seen that the ratchet wheel 26 on the hub 22 is engaged by the pawl 25 to prevent its movement in one direction but permitting its movement in the opposite direction. Said pawl is held against the ratchet wheel by a spring 27 Thus it will be seen that the rotation of the shaft 13 in one direction, due to .its connection with the shaft 10, upon which the wheel 11 is mounted, will rotate one of the discs when said wheel is rotated in one direction and will rotate the other disc when said wheel is rotated in the opposite direction, and that the backward movement of the wheels 16 and 17 will be prevented by the pawls 25 engaging with the ratchet wheels 26 on the outer hubs 22 of said wheels.

The two wheels 16 and 17 engaging with the two levers 19 and 20 serve to trip said 'levers so as to operate electric switches connected in a circuit with an indicator not shown- The circuit in which the switches are mounted is made or broken by the tripping of the lever. Thus when the shaft is rotated in an anti-clockwise direction, as seen in Fig. 3, the pins 18 will successively engage the lever arm 20. thus moving the arm downwardly and raising the arm 28 on the opposite end of the lever. This arm has a weight 29 thereon and its extremity is formed with an o ening therein to receive a pivot pin 30 by means of which it is connected with a rocking arm or rod 31.

The upper end of said arm has a head thereon, the outer side of which is formed with a shoulder 33, which is adapted to engage with the arm 34 at a point shown at at the right of Fig. 3. It will be seen'that the head 32 is adapted to move within a slot in the arnr 34, the shoulder 33 engaging upon the inner end of the slot at 35. The

* arm 31' is inclined outwardly so as to normally hold the shouldered face 33 against the end of the slot at 35..

The arm 34 is pivoted between its ends upon a shaft 36, mounted on the upper end of a post 37. It has a weight 38 on its outer end which tends to hold said end downwardly in the position shown in Fig. 0. lVhen in that position the arm is supported upon an adjustable bolt or pin 39 mounted in an arm 40 upon the post 37. Adjacent the shoulder 35 upon the arm 3% is an upwardly projecting stop member ell, said stop member being slightly spaced from the shoulder 35. Thus it will be seen that when the lever 20 is moved by the rotation of the wheel the arm 31 will be moved upwardly and as it is moved upwardly it will drop toward the shoulder 35 upon the arm Sal and bear against the stop member 41. 11011 the pin 18 upon the wheel has passed the lever arm 20 it will move backwardly through the force of the weight 29 and the arm 31 will drop downwardly, engaging the shoulder 35 and rocking the arm 31 on its pivot. As soon as the said arm is rocked into what is practically a. horizontal position the upper end 42 of the head 32 will engage against the stop member l] and be pushed laterally out of engagement with the shoulder 35 and the arm 31 will drop back into the position shown in the drawings.

Mounted on the rock arm 3 1 is a mercury contact switch 4-3. This switch is of common construction well known in the art. There are contact points at each end within a closed tube which are connected to conducting wires 15 leading to a main. conducting line shown generally at 4-6 in Fig. 2. These con tact wires are spaced apart and are adapted to be connected by a quantity of n'iercury shown at 17 in Fig. 3. Thus when the arm 34 is rocked by engagement with the arm 31 the n'iercury will flow down into a horizontal position, making contact with both of the wires in thecircuit, thus closing the same and energizing the magnet or similar means at the indicator. This type of switch is not included as a novel feature in applieants invention.

The circuit breaker thus provided is actuated by connectidn with a float 48 shown in Fig.1 and resting upon the upper surface of the liquid 49 in the tank. Said floathas a flexible line or chain shown at 12, which passes upwardly through a tubular support 51 and about a pulley 52 above the upper end of the casing 2. It passes from said pulley downwardly into the casing. A short pipe 53 projects downwardly through. the cover 7 in the casing and extends below the level of the liquid 3 in the said casing. The pulley or sheave 52 is enclosed within a. fluid tight housing 54:, so that gas which may escape upwardly from the tank through the tubular support51 may obtain access to the housing 54 for the pulley but may not escape into the casing 2 because of the fact that the lower end of the pipe 53 is submerged, making a seal against the gas at that point. i

The chain which forms a flexible line passes around the lower side of the toothed wheel 11 and upwardly around a second pulley within a casingfi l and back down through a tubular support 51 into the tank. A weight indicated at 55 on the opposite end of the line tends to hold the chain taut about the pulleys and the wheel as shown in Fig. 1.

The operation of my device will now be clear. The float 4L8 resting upon the liquid will be moved vertically, corresponding wit-h the level of the liquid in the tank. If the liquid is being removed from the tank the float will gradually lower with the level of liquid, thus rotating the toothed wheel 11 in a clockwise direction, as seen in Fig. 1, and this movement of the wheel will, through the rotation of the shaft 10, cause a rotation of he shaft 13, thus moving the proper wheel 16 or 17 so as to actuate the proper lever 19 or 20, thus rocking the proper arm 34 and thus closing the circuit at that point and energizing the circuit in such manner as to record the movement upon the indicator.

The advantages of this structure lies in fact that the larger part of the mechanism may be submerged in oil, thus keeping the bearings properly lubricated and keeping them free from material which might tend to clog the mechanism. It will e seen from Fig. 1 that I do not contemplate having the level of liquid high enough to submerge the switch member. It is unnecessary when the n'iercury type of contact member is employed to allow for a spark between the terminals. The switch is entirely enclosed. and there therefore no danger of igniting the gas which may find access to the casing 2. Fur hermore, the arrangement by means of which the rocker arm 34 is operated to close the circuit and to again release said rocker arm provides an operating device which may work rapidly without danger of failing to register through the proper closure of the electric circuit.

The device therefore, of simple construction and adapted to be housed within a smaller casing which may be supported upon the upper end of the tank. A large part of the usual mechanism connected with devices of this kind are hence dispensed with.

What I claim as new is: v

1. A liquid containing tank having an upper cover plate thereon, a casing mounted on said plate, a wheel mounted for rotation in said casing, a float in said tank, a flexible line attached at one end to said float and passing out of said tank about said wheel and back into said tank, a weight on the other end of said line, a circuit breaker op erated by said wheel, said casing being adapted to contain a liquid lubricant, and tubes through which said line is passed to said casing, the ends of said tubes bein submerged whereby a seal is provided against the escape of from said tank.

2. it. circuit breaker for an oil tank including a casing, a frame therein, a shaft in said frame, means to rotate said shaft responsive to changes .in liquid level in said tank, a pair of wheels mounted loosely on said shaft, a disc fixed on said shaft, means on said disc to engage and rotate one of said wheels when said shaft is rotated in one di reccion, a lever mounted for engagement with said wheel, a rod on one end of said lever, a rocking arm pivoted adjacent said rod, a switch on s: id arm, and means on said rod to engage and rock said arm when said lever is engaged by said wheel.

3. A circuit breaker for an oil tank including a casing, a frame therein, a shaft in said frame, means to rotate said shaft responsive to changes in liquid level in said tank, a pair of wheels mounted loosely on said shaft, :1 disc fixed on said shaft, means on said disc to engage and rotate one of said wheels when said shaft is rotated in one direction, a lever adjacent each of said wheels, means on said wheel to engage'and rock said lever, a rocking arm pivoted upon a post adjacent said lever, a mercury switch thereon, a rod connected with said lever and adapted. to engage and rock said arm'when said lever is rocked.

i. A circuit breaker for liquid level indicators including a liquid container, a casing thereon, a shaft rotatable in said casing, means on said shaft to rotate the same in response to changes in liquid level in said container, a rocking arm, a mercury contact switch thereon, a lever adjacent said shaft, means on said shaft to engage said lever when said shaft is rotated in one direction, and a rod on said lever engaging said arm to cause a rocking of said arm to close said switch when said lever is actuated.

A circuit breaker for liquid level indicators including a liquid container, a casing thereon, a shaft rotatable in said casing, means on said shaft to rotate the same in response to changes in liquid level in said container, a rocking arm, a mercury contact switch thereon, a lever adjacent said shaft, means on said shaft to engage said lever when said shaft is rotated in one direction, a red on said lever projecting through a slot in said arm, a shoulder on said rod engaging said arm, when said lever is moved, and means to disengage said shoulder from said arm when said switch has been closed.

ROY M. STAFFORD.

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