US1866334A - Quick release hydraulic operator - Google Patents

Description

July 5, 1932. WOODS 1,866,334

QUICK RELEASE HYDRAULIC OPERATOR Filed Nov. 6. 1930 Figl.

45 44 5 n 47 1 i l 46 Inventor: William J. Woods, y MAM His Atxlorney.

. Patented July 5, 1932 UNITED STATES PATENT OFFICE WILLIAM J. WOODS, OE SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK QUICK RELEASE HYDRAULIC OPERATOR Application filed November 6, 1930. Serial No. 493,902.

My invention relates to improvements in electro-hydraulic pressure-operated devices such as described in the copending applications of Walter O. Lum, Serial No. 193,016,

.5 filed May 20, 1927, and SerialNo. 415,341,

filed December 19, 1929, and assigned to the same assignee as the present invention.

The device referred to in the Lum application comprises a fluid cylinder in which is mounted a piston movable between an upper and lower position, the piston being biased to.

its lower position. An impeller pump within the casing is rotated by means of an electric motor to create a pressure in the fluid to raise the piston. One of the difliculties encountered in the device, hereinafter referred to as an operator, is the inability of the operator to instantly reset. This is due to the inertia of the rotor of the driving motor and of the impeller and its associated parts. When the piston has reached its upper or working position and the driving motor is deenergized to permit the piston to return to its initial position the inertia of the rotating rotor of the motor and the impeller causes the impeller to continue to rotate for a short period of time and to continue to create a pressure on the underside of the piston, thus maintaining the piston in its raised position until the energy of rotation has been dissipated permitting the pressure to fall off and the piston toleturn to its initial position. This prevents an immediate reset of the piston which action is desirable in certain types of operators.

Hence it is the principal object of my invention to provide an improved type of electro-hydraulic operator in which the effect of theinertia upon instant reset is eliminated as much as possible.

In the preferred embodiment of my invention I provide a fluid casing in the form of a cylinder which is vertically mounted. A piston is movable from its lower position to its upper position within the liquid and carries an impeller pump for creating a pressure differential between opposite sides of the piston to raise the piston within the casing. The impeller pump is driven through a splined shaft which connects the impeller pump and into the discharge side of the impeller pump.

When a pressure is created by rotation of the pump these bellows'expand to release the brake, thus permitting free rotation of the pump. Conversely, when the pump is deenergized and the pressure begins to fall the bellows contract, permitting the pump brake to return quickly to biased position to brake the rotation of the impeller pump. This permits a quick reset of the piston without the time delay usually necessary to dissipate the energy of the rotating rotor and impeller within the fluid in the casing.

In the accompanying drawing, Fig. 1 shows a cross section of the hydraulic .operator in the position of rest; Fig. 2 is a detailed showing of the piston structure, and Fig. 3 is a detailed showing of the brake mechanism.

In Fig. 1 the fluid casing or cylinder 10 which is filled with a fluid such as oil is provided with a covering or cylinder head 11 which supports the electric motor 12, the motor 12 being covered by means of the cupshaped member 13. A piston consisting of the parts 14 and15 is mounted to move in a vertical direction within the casing, the piston being biased to its lower position. The two a portion 18 which forms partof the brake structure. The splined shaft 17 is provided with the braking disc or element 19 which is positioned within the housing 18 (Fig. 3) i A,

brake 20 is biasedinto-engagement with the braking element 1 9' b'y fmeans the spring 21 which is held in position by the washer 22. Connected to the opposite ends of the brake 20 are the bellows members 23 and 21 which are screwed into the openings 35 and 31 in the top portion 15 of the piston. These bellows members are open to the exhaust of the impeller pump and are responsive to a pressure created by the impeller pump to move the brake against the biasing spring 21 to permit free rotation of the shaft 17.

The splined shaft 17 is mounted in the selfaligning bearing 25 carried by the lower portion of the housing 18. This permits movement of the splined shaft during operation of the operator so that should any slight misalignment take place no stresses will be introduced into the shaft or the pump housing formed by the piston.

The details of the pump housing as formed by the piston are shown in Fig. 2. The piston consists of the two parts 1-1 and 15.. Passageways 26 and 27 permit the fluid to enter the housing and contact with the upper part of the impeller blades through the opening 28. The fluid is led from the top part of the piston to the underside of the impeller by means of passageways such as 29 and 30 and the chamber 31. When the impeller pump is rotated the oil entering the top and bottom parts of the pump housing is expelled by the impeller blades in a radial direction through the openings such as 33 and 32 to the underside of the piston thus creating a pressure on the underside of the piston to raise the piston within the-cylinder. This pressure, of course, tends to expand the bellows, as pointed out, to move the brake member 20 against its bias.

The upper portion 15 of the piston carries the bushings 36 and 37 which support the connecting rods 40 and ll which in turn support the bridge member 42 carrying the workengaging eye 43. Stop members 38 and 39 mounted above the supporting bushings 36 and 37 limit the upward movementof the piston. The connecting rods slide in the bearings l4 and 15 mounted in the cylinder head and are provided with the slots 46 and 47. It will be noted that clearance is provided around the connecting rods in the cylinder head so that no oil will loak over the outside of the casing. If any oil is carried past the bearings which act as wipers it will flow to the spaces 41 and 45 between the upper part of the bearings and the cylinder head and will then pass through the slots 16 and 47 to the interior of the casing. The whole operator'is pivotally mounted by means of a pivot 4.8 on the bottom of the casing.

The operation of the device is as follows: lVhen the motor 12 is energized the impeller ump 16 is rotated by means of the splined shaft 17. The oil is led to the upper and lower sides of the impeller blades by means of the passageways 26, 27 and 28 to-the upper side and 29, 30 and 31 to the lower side and expelled through the exhaust passages 32 and 33, thus creating a pressure on the underside of the piston. The bellows members are quick to respond to this pressure and expand to force the brake 20 against the biasing spring 21 to thereafter permitfree rotation of the impeller pump and shaft. The piston will rise within the cylinder until further movement is prevented by contact of the stop members 3S and 39 with the bearings 44 and 45. The piston will remain in the upper position so long as the impeller pump is rotated.

When the motor 12 is deenergized to permit the piston to return to its lower position the speed of the impeller pump begins to drop and hence the pressure. A slight drop in the pressure on the underside of the piston permits the bellows members to quickly collapse thus permitting the spring 21 to move the brake member 20 into engagement with the braking element 19 carried by the splined shaft 17. This action quickly brings the pump and motor to rest which, of course, permits the immediate return of the piston to its biased position. The brake acts quickly and thus eliminates the time delay due to continued operation of the pump which would otherwise take place due to the inertia of the rotor of the driving motor and pump.

It will thus be seen by using my unique method for eliminating the effect of inertia I provide a quick resetting hydraulic operator. Further, by placing all the parts within the oil in the fluid casing wear is reduced to a minimium, thus eliminating the necessity for constant repairs.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the different conditions encountered in its use, and I, therefore, aim to cover by the appended claims all of the modifications within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A hydraulically operated device including a fluid casing, a piston therein movable between two positions and biased to one of said positions, a pump for creating a pres sure within the fluid to move said piston to the other of said positions, a driving motor therefor, a brake for said pump biased to a braking position, and means responsive to the pressure of said pump for releasing said brake, said brake acting to stop said pump immediately after de-energization of said motor whereby said piston will return to its biased position without delay.

2. A hydraulically operated device including a fluid casing, a piston therein movable between two positions and biased to one of said positions, a pump for creating a pressure in the fluid to move said piston to the other position, a driving motor for said pump, a drive shaft operatively connecting said pump and motor, a braking member carried by said drive shaft, a brake cooperating therewith and biased to the braking position, and means responsive to the pressure created in the fluid by said pump for releasing said brake, said'brake acting to stop said pump immediately after de-energization of said motorgwhereby said piston will return to its biased position without delay.

3. A hydraulically operated device including a fluid casing, a fluid therein, a piston movable in said fluid, a pump for creating a pressure in the fluid to move said piston, a

driving motor for said pump, a drive shaft operatively connecting said pump and motor, a braking member carried by said drive shaft, a brake cooperating therewith and biased to the braking position, bellows members in said fluid adapted to expand in response to pressure created by said pump in said fluid, said bellows being connected to said brake member'to release said brake member when said pump is-operated.

4. An electro-hydraulic operator including a fluid casing, a piston therein, a pump for creating a pressure in the fluid to move said piston, an electric motor for driving said pump, a. drive shaft connecting said pump and said motor, a brake for said shaft carried by said piston and biased to braking position, and means carried by said piston to release said brake and responsive to the fluid pressure exerted on said piston when said pump is operated.

5. An electro-hydraulic operator including a fluid casing, a piston therein, a pump carried thereby for creating a pressure in the fluid to move said'piston, an electric motor for driving said pump, a drive shaft connecting said pump and motor, a braking member carried by said shaft, a brake cooperating with said braking member and biased to braking position, members carried by said piston responsive to the pressure of said pump in the fluid, said members being operatively connected to said brake to release the brake in response to said pressure.

6. An electro-hydraulic operator including a fluid casing, a piston therein movable between two positions and biased to one of said positions, all impeller pump for creating a pressure in the fluid to move the piston to the other position, an electric motor for driving said impeller pump, a driving shaft connecting said motor and said pump, a brake for said pump cooperating with said shaft and biased to a braking position, said brake being responsive to pressure created by said pump to move from its braking position to permit free rotation of said shaft and pump, said brake immediately aftwithout delay.

er de-energization of said motor returning to braking position to stop said pump whereby said piston will return to biased position 7 An electro-hydraulic operator including a fluid casing, a piston therein, an 1111- peller pump carried by said piston for creatng a pressure in the fluid to move the piston, an electric motor for driving said impeller pump, a splined shaft connecting said motor and said pump, a braking element carried by said splined shaft, a brake cooperating with said braking member and biased to the braking position, said brake being responsive to pressure created bysaid pump to move from its braking position to permit free rotation of said shaft and pump.

8. An electro-hydraulic operator including a fluid casing, a piston therein movable between two positions and biased to one of said positions, an impeller pump housed in said piston for creating a pressure in the fluid to move the piston to the other position, an electric motor for driving said impeller pump, a driving shaft connecting saidmotor and said pump, a brake for said pump cooperating with said shaft, means biasing said brake to braking position, bellows members carried by the piston and operatively connected with said brake, said bellows members being .responsive to the pressure created by said pump to move said brake against its bias to permit free rotation of said shaft and pump, and upon a decrease in the pressure beneath said piston when said motor is deenergized permitting said brake to immediately return to its braking position to render the inertia of said driving motor and impeller ineffective to maintain said pressure.

9. An electro-hydraulic operator including a fluid casing, a piston therein, an impeller pump for creating a pressure in the fluid and housed by said piston, an electric motor for driving said impeller pump, a splined shaft connecting said motor and said pump, a brake forsaid pump cooperating with said shaft and biased to a braking position, bellows members carried by said piston and operatively connected to said brake to movethe brake to an unbiased position in response to pressure created by said pump, said bellows members being open to the exhaust side of said pump whereby said bellows members will be instantly responsive to pressure changes when said pump is energized and deenergized by said motor.

In witness whereof, I have hereunto set my hand this fifth day of November, 1930.

' WILLIAM J. WOODS.

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