US2339728A - Hydraulic control mechanism - Google Patents

Description

Jan. 18, 1944. P. c. TEMPLE HYDRAULIC CONTROL MEGHANISM Filed OCT.. 31, 1941 PA UL C. TEMPLE' Patented Jan. 1s, 1944 UNITED -HYDRAULIC CDNTROL MECHANISM I Paul C. Temple, Decatur, Ill., assignor to A. W.

Cash Company Delaware Decatur, Ill., a corporation of Application october 31, 1941, serial No. 417,283 (ci. eof54.5)

2 Claims.

This invention relates to hydraulic control mechanism, and more particularly to mechanism adapted to transmit motion from one element to another element remote therefrom, through v the medium of a hydraulic fluid.

A mechanism of this type'includes a sender or compressor unit, and a receiver or motor unit. It is desirable that the motor unit should remain stationary except at such times as motion-is imparted thereto by actuating the compressor` unit. As a practical matter, however, itis very dif- 'flcult to avoid some slight leakage of the hyv It is a further object of the invention to provide a hydraulic control mechanism including a manually operable sender and a receiver, with r simple and dependable means whereby the operator may control the movements of the receiver and ensure its remaining stationary when no movement is desired.-

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the speciication` and covered by the claims appended hereto.

Referring to the drawing illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. l is a somewhat diagrammatic view of a hydraulic control mechanism connected to a damper, with certanparts shown in section on the line l-I of Fig. 2; and

Fig. 2 is a section on the line 2-2 of Fig; l.

The embodiment illustrated comprises a sender orcompressor unit I and a receiver or motor unit II. The sender I0 includes a hollow casing I2 having a removable cover plate I4 andforming a reservoir for a suitable hydraulic fluid such as oil. Two vertical cylinders I5 and I6 are secured to the bottom wall of the casing I2, with the upper portions of the cylinders extending into the casing. The upper ends of the cylinders are open. Within the cylinders I5 and I6 there are mounted two slidable pistons I8 and I9 respectively. These pistons are joined by connecting rods to the opposite ends of a rocker arm 22 secured to a horizontal shaft 23. This shaft is supported in two spaced bearings 24 in the casing I2. One end of the shaft extends outside the casing, and to'this end there is secured an upwardly extending handle or lever 26 which can be swung back and forth to oscillate the shaft and thereby actuate'the pistons I8 and I9. Each of the cylinders I5 and I6 is provided with a po'rt 21 in the wall thereof so located that it will be uncovered when the corresponding piston is raised to its uppermost position. These ports open into the interior of the casing I2, and they make it possible for air to .escape from the cylinders and for oil to enter the same. r

The receiver II comprises a hollow casing 23 having a bearing 29 therein for the support of a horizontal rotatable shaft 30. 'I'his shaft ex- -tends outwardly. from the casing through a stufling box 32.- On the outer end of the shaft there is mounted an arm 33 which is connected by a link 34 to the operating arm 36 of a valve or damper 31 arranged to control the flow of fluidv in a duct 38. A horizontal cylinder 48, is secured to the casing 28, the outer end-*of the cylinder being closed and its inner end being open and communicatingwith the interior of the casing. Within the cylinder there is mounted a slidable piston 4I which is joined by a connecting rod 42 to an arm 43 secured to the shaft 30vwithin the casing 28. As the piston 4I moves from one end of the cylinder 40 to the other it will oscillate the shaft 30 and the arm 33, and this in turn will actuate the damper 31.

The receiver piston 4I is actuated by hydraulic pressure resulting from movement of the sender pistons I8 and I9. For this purpose the lower end of the cylinder I5 is connected bya pipe 45 to the outer end of the horizontal cylinder 40,

and the lower end` ofthe cylinder I6 is con-` nected by a pipe 46 and passageway 41 to the inner end of the cylinder 4I). This passageway 41 is formed partly in the cylinder 40 and partly in the casing 28. The cylinder 4I!! is provided with'two ports 49 and 50 which are'so located as to be respectively uncovered by the piston 4I when it reaches its outward and inward travel limits. The port 49 is connected to the outer end of the cylinder by means of a passageway 5I,

and 'the port 58 is connected to the inner end of the cylinder by the heretofore described passageway 41. In order to prevent fluid from entering the cylinder through these ports 49 and 58, they are provided with spring loaded check valves 53 and 54 respectively.

It will now be apparent that if the handle 26 is moved to lower the piston i8, oil will be forced through the pipe 45 into the outer end of the cylinder 40, moving the piston 4| inwardly. If the piston 4| reaches its inner travel limit before the piston .I8 reaches the bottom of its stroke, the piston i8 can Anevertheless be made to coinplete its travel since the extra oil.can escape through the port 50 and past the check valve 54. Similarly, if the handle 26 is moved in the opposite direction to lower the piston I9, oil will be forced through the pipe 46 into the inner end of lthe cylinder 40, moving the piston 4| outwardly.

-piston 4| and the dampere31 can be moved to any .desired 'position by merely moving the handle 26.

In many cases `it is important to hold the damper 31 or other controlled device in a fixed position in spite of unbalanced forces tending to cause movement thereof. For this purpose it has been proposed `to provide means for clamping the operating handle (such as the handle 26) in a It is found,

movement of the receiver piston will nevertheless occur even with the sender pistons stationary, since a slight leakage of the oil is unavoidable. Hence after a prolonged period it will be vfound that the-damper or other device has moved considerably out of position. The present invention avoids this diiiiculty.

Referring now to Fig. 2, it will be seen that a stationary cylinder 56 is connected to the receiver casing 26 by means of struts 51, this cylinder surrounding the shaft 30 between the casing 26 and the arm 33. The outer end or head oi. the cyllnder 56 is shaped to provide a bearing 5B for the haft 3|). Within the cylinder there is mounted a piston 60 which is secured to the shaft 30 tov prevent relative rotation between the shaft and the piston. These various parts are so constructed and arranged that by supplying pressure fluid to the cylinder 56 it is possible to hold the piston 60 firmly against the inner end of the cylinder, the` resultant friction preventing rotation ofthe piston, as well as the shaft 30. A pipe 62 is connected to the cylinder 56, and it will be understood that this pipe may lead from a compressed air tank or other suitable source of pressure fluid. The piston 66 and cylinder 56 forms a iiuid-actuated friction brake or locking device for 'theshaft 30.

Means is provided whereby the operator may release the receiver lfrom the restraining effect of this locking device when he wishes to impart motion to the damper 31. This may be accomplished by relieving the air pressure in the cylinder 56. For this purpose the pipe 62 is provided with a restriction in the form of an oriiice plate 63, and manuallycontrolled means is provided to allow air to escape from the cylinder at a faster rate than it can enter through the oriflce. As shown in Fig. 2, one end of the sender` shaft 23 extends through annular sealing means `65 into a chamber 66 formed in a hollow plug 61 screw-threadedinto the casing |2 in alignment I handle 26, this latter passagel leading to a valve 13 which can be opened by means of a push button 14 mounted in the upper end of the handle. The valve is normally held closed by a coiled compression spring 15, and when itis opened air is free to escape from the passage 1| into the atmosphere.

The operation of the invention will now be apparent from the above disclosure. With the valve 13 closed, the air pressure in `the cylinder 56 of the receiver will be equal to that in the tank or other source of supply, and the piston 60 will be held firmly against the end wall of the cylinder, e'iiectually preventing any rotation of the shaft 30 or movement of the damper 31 connectoffer negligible resistance to the rotation of the shaft 30, and it will be possible to actuate the receiver by simply moving the sender handle 26. When the damper 31 has been moved to the position desired, the operator will release the push button 14, allowing the spring 15 to close the valve 13. will thereupon increase, and the brake will be applied to hold the damper fixed in its new position.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Hydraulic control mechanism comprising a hydraulic motor having a shaft, a compressor unit,

. means to conduct hydraulic fluid from the compressor unit to the motor to turn the said shaft, a cylinder surrounding the shaft, a piston with.- in the cylinder and connected to the shaft to turn therewith, means to deliver pressure fluid to the cylinder to hold the piston firmly against one end of the cylinder and thereby prevent rotation of the piston and shaft, and manually controlled means associated with the compressor unit to relieve the pressure in the cylinder.`

2. Hydraulic control mechanism comprising a hydraulic motor, a compressor unit having a pivotally mounted operating lever of hollow construction shaped to provide a chamber therein, means to conduct hydraulic iiuid from the vcompressor unit to the motor to actuate the same, a locking device associated with the motor to restrain movement thereof and arranged to be actuated by compressed air, a restricted conduit to supply compressed air continuously to the locking device, a conduit connecting the locking device with the said chamber, and a manually'operable valve mounted on the lever to allow discharge of air from the chamber to the atmosphere.

' PAUL C. TEMPLE.

The air pressure in the cylinder 56

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