US2044746A - Circuit controlling system - Google Patents

Description

w. H. HOLLINSHEAD 2,044,746

CIRCUIT CONTROLLING SYSTEM June 16, 193

2 Sheets-Sheet 1 Original Filed March 16, 1934 June 16, 1936. w. H. HOLLINSHEAD' CIRCUIT CONTROLLING SYSTEM 2 Sheets-Sheet 2 Original Filed March 16, 1934 INVENTOR Wfl. Hollinlhead BY #4. M/ W ATTORNEYS Patented June 16, 1936 UNITED STATES PATENT OFFICE CIRCUIT CONTROLLING SYSTEM William H. Hollinshead, St. Paul, Minn., assignor to Water Level Controls Company, St. Paul, Minn., a corporation Original application March 16, 1934, Serial No. 715,898. Patent No. 2,012,428, dated August 27, 1935. Divided and this application April 8, 1935, Serial No. 15,205

4 Claims. (Cl. 175-320) My invention relates to circuit controlling sysof a diaphragm case I8 in whose upper end is tems. While intended more particularly for use secured an annular member 20. Within the case in connection with the control of water levels in Hi, there is a long flexible diaphragm 22 whose tanks and sumps, it is to be understood that the upper end is tightly secured to the lower surface system may be appliedto other uses. Anobject of the member 20. The diaphragm 22 hangs 5 of the invention is to provide a device of this freely from the member 20 so that fluid pressure character which is efiicient and dependable in transmitted through the pipe I6 is imposed upon operation and not affected by expansion and conthe bottom of the diaphragm. A vertical tube traction due to changes in temperature. An- 24 is centrally disposed within the diaphragm other object is to provide a device which emwith its upper end extending up through the 10 bodies a support mounted for rotative movement, opening in the annular member 20. A rod 26 a ource of pressure for imparting rotative movein the tube 24 is threaded on its upper portion ment to said support in one direction when the and provided with a nut 28 adapted to rest upon pressure increases and in the opposite direction top of the tube 24 whereby adjustment up and when the pressure decreases, a switch carried by down may be made. The upper end of the rod 15 said support closed by movement of the support 26 is provided with a knife edge 30 which engages in one direction and opened by movement of the in a notch 3| formed in the lower side of an armsupport in the other direction, a circuit con- 32 which at one end has a pivot 34 carried by a trolled by said switch, and a. snubber acting to bracket member 36 secured to the inside of the prevent the efiect of surging in said pressure casing 8, it being noted from Fig. 2 that the 20 source from being imposed on the circuit. upper end of the diaphragm case I8 is secured This application is a division of my application, to the bracket 36. A coiled spring 38 is attached Serial Number 715,898, filed March 16, 1934, at its upper end to the movable end of the arm which has matured into Patent Number 2,012,428, 32. This spring extends downwardly and its dated August 27, 1935. lower end is attached to a screw extending 5 The full objects and advantages of my inventhrough the bottom of the casing 8 and provided tion will appear in connection with the detailed on the outside thereof with a nut 42 by means of description thereof and the novel features emwhich the tension of the spring may be adjusted. bodied in my inventive idea will be particularly One end of a flexible strip 44 is intermediately pointed out in the claims appended at the end of secured to the arm 32. The other end of this 30 the specification. strip is secured to the periphery of an annular disk In the accompanying drawings which illustrate 46 mounted for rotative movement on an ena practical embodiment of my invention-Fig. 1 larged portion of a bolt 48 carried by the support is a view in front elevation of the device after 36 as shown inFig. 3. A pendulum 50 is secured the front of the casing has been removed. Fig. 2 to the disk by bolts 52 so that the bolt 48 con- 35 is a view in vertical section on the line 22 of stitutes the pivot of the pendulum. The lower Fig. 3. Fig. 3 is a view in vertical section on the end of the pendulum is provided with an arcuate line 33 of Fig. 1. Fig. 4 is a View in Vertical slot 54. A bolt 56 passing through said slot and section on the line 4-4 of Fig. 1. Fig. 5 is a fragthrough a weight 58 serves to adjustably secure mentary view taken on the line 55 of Fig. 1. the weight on the lower end of the pendulum. 40 Fig. 6 is a view in horizontal section on the line The upper end of the pendulum 50 is positioned 66 of Fig. 1. between the annular disk 46 and a flanged mem- Referring to the construction shown in the her 0. t bolts 52 i s y referred to passin drawings, the numeral 8 designates a casing for through the flange 0 the member the device, the front of this casing being provided A supporting disk 62 is secured to the outer with a door It hinged at the bottom as indicated face of the member 60 by a screw 64 whereby the at 12 in Fig. 3 and having a transparent panel I4 disk 62 constitutes a 'movable support which through which the interior of the casing can be moves to and fro together with the annular disk seen without opening the door. The casing may 45 and the pendulum 50. The movable support be constructed of any suitable material and may 62 serves to carry a plurality of contact members 50 be placed in any convenient location. A pipe 16 shown in the present embodiment as consisting of leads into the bottom of the casing, this pipe two mercury switches embodying two tubes 66 being connected to a liquid or gaseous supply and 68 disposed substantially diametrally upon which is to be controlled. The end of the pipe the opposite sides of the support 62. It will be it in the casing is connected into the lower end understood as a matter of course that the support from maximum to minimum.

62 is capable of carrying additional mem hers. The tubes and are held by similar clips l8 attached to segmental members it re= spectively. Each segmental member is attached to the support by a pivot screw i l and is provided with an arcuate slot 76 through which a screw '58 passes whereby the tubes and 68 may be independently adjusted. The tube toward its outer end is provided with two terminals and irie te :oiual 8E9 is connected by a e with a binding post carried by a block oi insulating material secured inside of the casiug 8 as shown in Fi 3. The terminal 82 connected. by a wire till with a binding post 92 carried by the block 88. The tube 68 toward its outer end is provided with two terminals 9 and The teiwiinal 9G is connected by a wire 98 w. i a post lilo carried by the bloclr The terminal is connected by a wire M2 w a binding post lil l carried by the block Se cured within the casing is a bracket o which the lower end of a bimetallic bar tilt) is secured. he upper end of the bar ace carries a clip i i ll which holds a mercury switch. embodying a tube H2. The tube M2 is provided with. two terminals lid and i E6. The terminal lid is connected by a wire [I ll with the binding post till] while the terminal 6 is connected by a wire 62d with a his leg post 822 carried by the block The oraclret Hi6 carries a resistor well known construction, the lower portiouoi which is connected by a wire E26 with a binding l 23 carried by the block The upper portiou of the resistor is connected by a wire Hill] w h the binding post the wire including a heating coil wrapped around the bimetallic bar Hit. The binding posts and Q2 are connected by wires i3 3 and respectively with a motor which is to be controlled. The binding posts ltd, tilt, and G22 are connected by wires G38, M@ and M2 respectively with a motor starter associated with a motor, the wire E38 being a starting line, the being a common line and the wire i 32 being a stopping line as commonly employed in three systems.

The operation and advaritages of my invention will be understood, in connection with the fore going description and the accompanying draw= iugs. fig. 1 shows the parts in the position which. they assume when the pressure is the pipe to has reached the desired maximum and the motor is to be stopped. The pressure exerted on the diaphragm 22 has turned the 62 against the gravity of the pendulum oil and the tension oi the spring This causes the mercury in the tube to bridge the terminals 8t and so that current flows through the wire [13 3, the G26, the resistor lit, the wire ltd including the heating coil (132, the wire 80, the wire to, and out ti'irough the wire 136. The heating coil Q32 soon flexes the thermostatic bar tilt from the position shown in Fig. i into that shown in Fig. 2, so that the mercury in the tube [1 l2 opensthe terminals lit and l [16. Current now ceases to flow through the wire Mil, the wire lit, the wire ltll, and the stop wire 1 32 so that the motor is stopped. in the embodiment of invention shown in the drawings, the system is arranged to take care of surging caused by operation of a pump actuated by the motor which is being controlled. Obviously the pump is not operating so as to cause surging during the time when the pressure is dropping in other words, the operation of the system is not afifected by starting surges as will. now be explained. When ace-eves the pressure in the pipe it falls sufiiciently so that the pendulum lit and the spring 38 the disk. in the opposite direction the requisite distance, the mercury in the tube bridges the terminals 9 and 96. Current now flows through 5 the wire Mil, the wire 98, the tilt, and the starting wire so that the motor is started. It is to be noted that the thermostat i238 and the resistor 52G serve as an electric snubber' so that rapid vibration of the disk 52 due to surging in m the fluid whose pressure is imposed on the dia= phragri will not cause starting and stopping of the motor in rapid succession. Surging source of fluid pressure will not cause cu. rent stop flowing through the stop wire 1412 even if 15 the disk should be momentarily rocked sufficiently to bridge the terminals Stl and 82 since the current would fust have to flow tlucugli the resistor and the heating coil around the thermo stat and this to flex the thermostat requires go a greater period or time than the period of vibra tiori due to surging. While I prefer to employ the electric snubber which has been described it is apparent that some other form of snubber might be employed so that it would not be ueces- 2s sary to provide the thermostat M8, the resistor ti l, the mercury tube i ii and the wires associated with these parts. My device has the advantage of not being materially ailected by expansion and contraction caused by changes in temperature. so

By tightening the spring some of the elect of the pressure exerted on the diaphragm 22 is over= come. The provision of both the spring and the pendulum acting on the arm cuts dovm the periodoi vibration of the disk (52. be noted further t at the device is being minutely and accurately adjusted.

'i claim:

1. A circuit controlling system comprising a support mounted for rotative movement, a plu 4 rality of sets of contact members carried by support, a source of pressure for a to and fro rotative movement to said support, a circuit adapted to be closed by one of said sets, a resistor in said circuit, a heating coil in cir cult, a thermostat with which said coil is asso= ciated, a switch normally in closed position and opened by expansion of said thermostat, a stop wire and a start wire associated with a motor; a circuit including said swiwh and stop wir and 50 a circuit including the start wire adapted to be closed by another of said sets.

2. A circuit controlling system comprising a support mounted for rotative movement, a plu rality of mercury switches carried by said sup port, a source of pressure for imparting a to and fro rotative movement to said support, a circuit adapted to be closed by one of said switches, a resistor in said circuit, a heating coil in said circuit, a thermostatic bar around which said coil (30 is wrapped, a mercury switch carried by said bar normally held in closed condition and opened when said bar is flexed by the heat of said coil,

a stop Wire and a start wire associated with a motor; a circuit including said switch. and stop 65 Wire, and a circuit including another of said phi-- rality of switches and the start wire.

3. A circuit controlling system comprising a source of pressure, a switch closed by high pressure and opened by low pressure in said source, a second switch closed by low pressure and opened by high pressure in said source, a. circuit adapted to be closed by one of said switches, a resistor in said circuit, a heating coil in said circuit, a thermostat with which said coil is assoc ated a it will 35 cosmos switch normally in closed position and opened by expansion of said thermostet, e stop wire and, e, start wire associated with e motor, e, circuit including said third switch and stop wire end a circuit including the start Wire adapted to be closed by the other of said pressure operated switches.

i. A circuit controlling system comprising e source of pressure, a switch closed by high pres= sure and opened by low pressure in said source, at second switch closed by low pressure and opened by high pressure in said source, e circuit adapted .3M H. HOLL'INSHEAD.

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