US1115511A - Safety device for pump-governors. - Google Patents

Description

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WITNESSES SAFETY DEVICE FOR PUMPGOVERNORS.

'Specification of Letters Patent.

Application led October 9, 1912. Serial No. 724,708.

To all whom it may concern:

Be it known that I, 191111.11 l L. Cnri'rl-:N- DEN, a citizen of the United'States, residing 'at Edgewood, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Safety Devices for Pump-Governors, of which the following is a specification.

This invention relates to pump governors forgmotor driven v'fluid compressors, and

. more particularly to a safety or protection device adapted to he employed in connection therewith.

It has heretofore been customary to provide some form of unloading or starting device in connection with the governor of a' motor driven fluid compressor so that'in starting, the motor can attain its normal speed without undue load.l It occasionally happens, however, that current gives out temporarily and if the pump governor should happen to be in the cut-in position at that time, the parts will remain in said position and then when the current comes on again, the unloading device will be ineffective to prevent undue load on the motor.

The principal object of v provide means for automatically causing the pump governor to shift to the cut-out osition upon failure of current, so thatv when current is again supplied, the starting or unloading device will bein the position to pass through the necessary cycle for preventing an undue starting torque or excessive load on the motor.

In the accompanying drawing; Figure 1 is a sectional view of an electric pump governor with my improvement applied thereto and Fig. 2 a diagrammatic view of a motor driven fluid compressor equipment showing my invention embodied therein.

In order to illustrate one form of my invention, an electric pump governor 1 of a well tacts 3 adapted to engage with stationary switch contacts 4 for closing the `circuit which supplies current to the electric motor of the air compressor 8. A main valve mechanism .cmprising a valve 5 and pistons 6 -and 7 controls the admission and release of fluid under pressure to and from the switch piston 2.

my invention is tov parts of the A low tension regulating device comprislng a dlaphragm 9 subject on one side to pressure through passage 10 controls a va ve 11 adapted to govern the release of the piston 7 and I regulating device comprising a dlaphraglm 12 subject on one side to pump pressure t rough the passage 13 controls a valve 14 for i 6. A passage 15 su plies fluid at pump pressure to valve chamer 16 and pistons 6 and 7 being loosely fitted, fiuid equalizes on opposite sides of said pistons.

When the ump pressure is less than the adjusted tenslon of spring 17, the 9 opens valve l1 andvents fluid from the piston 7, causing the to assume the position shown in Fig. 1, in which a cavity 18 connects port 19 leading to switch piston 2 with an exhaust port 20, so that piston 2 is pressed vto its inner positionby spring 21, closing the switch and the pump circuit. Upon a rise in pump pressure to exceed that of spring 22, the valve 14 is opened, valve 11 having been previously closed by the rise in pump pressure acting on diaphragm 9. Fluid is thereupon vented from piston 6, while fluid under pressure has equalized around pistonl 7 and the main valve mechanism is shifted to its opposite position, 4in which'passage 19 is opened to valve chamber 16, so that fluid under ressure is admitted to piston 2, thereby shi ting Same to its outer position, breaking the pump motor circuit.

Any type of unloading device may be employed, the form shown in the drawing being circuit in starting the starting device 23 having a piston a piston 25, subject the motor. As shown, may comprise a casing chamber 24 containing on one side to the pressure of a spring 26 and having its opposite side connected by a pipe. 27 to a 28'leading to the seat Upon movement of the main valve mechanism to the cut-in position, as shown in Fig. 1, a restricted port 31 in the valve 5 registers with port 28, so that fluid is gradually sup- Patented Nov. 3, 1914.

piieri rrom valve cnainoer 16 to the piston chamber 24. By ment of the piston is etlected and thereby the drum 29 is rotated to gradually cut out resistance in the motor circuit.

According-to my improvement, means are provided t'or automatically eecting the movement of the electric pump governor to its cut out position upon ailure oit current in the line circuit and for this purpose l preterahly employ a valve 32 controlled by a magnet 33, connected across the line circuit, as shown in Fig. 2, for venting fluid from tlie piston 6 of the main valve mechanism of the governor.

rlhe valve 32 the energizatilon of the magnet is normally held closed by the current fails, the valve 32 opens and fluid 'is vented from piston a drop in punp i 6 through pipe 34 to exhaust porty 35. By this means, if the pump governor should happen to be in its cut-in position when the current `i'iiils, the operation of the magnet controlled valve 32 automatically etlects the shifting o the governor parts to the cut-out positioinso that when the current again comes on, the governor will be in the ciit-out position and when the governor subsequently moves to cut-.in position, due to pressure, it will be evident `that the unloa or starting device will be ready to operate in the usual manner to prevent lan undue starting load on the pump motor.

lt will be understood nient may be employed in connection with various types of starting devices, such as the torni in which. an automatic valve device operates to relieve the iiuid pressure on the pump piston at starting, a variable resistance. adapted to be gradually cut out of the uiotorcircuit as the speed increases, or in connection with alternating current on single phase motors where various employed the motor.

Having now that my improvethis means a gradual movey current to the actuating piston 33, but when devices are to reduce the starting torque of described iny invention. what l miseri l claim as new and desire to secure by Letters Patent, is zl. The combination with an electric motor driven pump for compressing huid and a governor controlled by variations in pump pressure for opening and closing the pump motor circuit, of a magnet controlled by current supplied from the source which supplies ump motor circuit and a valve controlled y said magnet and adapted upon failure of current to open and vent fluid from said governor to sliit same to its cut-out position.

2. The combination with an electric plump overnor comprising an electric switc an therefor, and a valve mechanism operated according to variations in punippressure for controlling the fluid said actuating. piston, of an electro-macnetically controlled valve opero ated upon failure ot current for venting duid from said valve mechanism to thereby electric switch cliect tlie movement of said to the cut-out position.

rlhe combination with an electric plump overnor comprising an electric switc or controlling the pump motor circuit, an actuating piston therefor, a valve for controlling the fluid pressure on said piston, and a movable abutment operated by yenting fluid from one side thereof for actuating said valve to vary the duid pressure on said piston to thereby shift the switch to cut-out position, ot a magnet normally energized by 1 current supplied trom the sourcewhich supplies current to the pump motor circuit and a valve controlled by said magnet and adapted upon failure of current to vent fluid from said abutment.

"in testimony my hand.

whereof l have hereunto set Pliliill) L. Gill'l'lllNDEl'.

Witnesses A. M. Gniiiiinn'rs, lV. W'. Maurin.

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