US2845902A

US2845902A - Self-locking fluid motor

Info

Publication number: US2845902A
Application number: US480533A
Authority: US
Inventors: J Edward C Anderson
Original assignee: Borg Warner Corp
Current assignee: Borg Warner Corp
Priority date: 1955-01-07
Filing date: 1955-01-07
Publication date: 1958-08-05
Anticipated expiration: 1975-08-05

Description

Aug- 5, 1958 J. E. c. ANDERSQN 2,845,902

SELF-LOCKING FLUID MOTOR 5 Sheets-Sheet 1 Filed Ja n. 7, 1955 xw. Qkw m hdl n Nuo I l N I l @Jn n A hm v e f. r .r .vw ,TO F.TX MlH R5). ma. @C M u w NQ U NQ .@Q 7@ F l w J E 2M w www Q Q N Q w m ww m Q nl.. wm N@ 1 4;

Aug. 5, 1958 J. E. c. ANDERSON SELF-LOCKING `FLUID MOTOR 3 Sheets-Sheet 2 Filed Jan. 7. 1955 Aug. 5, 1958 J. E. cK. ANDERSON A SELF-LOCKING FLUID MOTOR 3 Sheets-Sheet 3 Filed Jan. 7. 1955 THQ JN ausl, m.Q\.\ T V NGN ///////M` ///7///// Y 1 w @SMR um Sx mi .W W h 18 extends, and is further provided with an opening 27 establishing communication between the

openings

25 and 26. Disposed within the opening 25 is a piston guide 28, generally circular in form, which has an inner cylindrical surface slidably in engagement with the rod 9 and an outer cylindrical surface in engagement with the sides defining the opening 25. Suitable sealing means are provided between the piston guide 28 and the body 24, and between the piston guide 28 and the rod 9, as illustrated in Figure 1.

The right hand surface of the piston guide 28, from the view of Figure l, is disposed in abutting relationship with the innermost surface of a collar 29, a cross-sectional view of which is shown in Figure 3. As seen in that ligure, this collar comprises a plurality of discreet,

tapered segments

31, 32 and 33. Each of these segments has an outer curved surface (respectively designated 31a, 32a and 33a) adapted to complementarily engage the wall of a tapered opening 34 extending from the right exterior surface of the Vbody 24 to the opening 25 formed in the body. The angle 34a is of the order of 5-15, and preferably is about 13. Each ofthe segments 31 through 33 is further provided with a curved inner surface, designated by the numbers 31h through 33b, adapted to cornplementarily engage the outer surface of the rod 9. Each of the segments 31 through 33 is separated from each of the other segments. The outermost ends of each of the segments 31 through 33 is formed with a ledge of the nature illustrated at 35 against which one end of a circular spring 36 abuts. The opposite end of the spring 36 engages a transversely extending portion of an end cover 37 having an loutermost opening 38, circular in nature, therein. Disposed with the opening 38 and in fixed engagement with the cover 37 is a circular grommet 39, the outer periphery of the grommet 39 being formed with a trough for receiving the associated side of the cover 37. The interior of the grommet 39 is provided with a circular opening which is disposed in slidable engagement with the exterior surface of the rod 9. Disposed in engagement with the inner surface of the grommet 39 is a cylindrical dust seal 41, having a central, circular aperture therethrough which is also disposed in slidable engagement with the outer surface of the rod 9. As clearly indicated in Figure l, the cover 37 is provided with an axially extending portion 42, which completely surrounds the spring 36, and radially extending portions 43 having suitable apertures therein through which the bolts 23 extend to fixedly mount the end cover 37 to the body 24.

To operate the device previously described, there is preferably provided control mechanism of the type diagrammatically illustrated in Figure 7. This ligure shows schematically the cylinder I, in which the rod 9 is disposed for longitudinal reciprocation in response to fluid pressure, the ports and 7 being illustrated in iiuid comi munication with opposite ends of the cylinder 1. Ports 5 and 7 are connected by suitable conduit means 45 and 46, respectively, to ports 47 and 48 of a valve mechanism illustrated generally by the numeral 49. This mechanism 49 comprises a cylinder block 51 in which ports 47 and 48 are disposed, the opposite side of the block 51 being provided with

ports

52 and 53 as illustrated in Figure 7. The port 52 is preferably connected to a sump (not illustrated) while the port 53 is preferably connected to a suitable source of fluid under pressure, such as a pump, which may also be connected to supply other hydraulic units. The block 51 is also provided with a longitudinally extending cylindrical aperture 54 which is in uid communication with

ports

47, 4S, 52 and 53. Disposed Within the opening 54 is a Valve member 55 which is generally circular in cross-section and which is provided with outwardly extending collar portions 56, 57 and 58 in engagement with the walls dening the opening 54. The collar portion 59 is provided with suitable seal means, as illustrated in Figure 7, cooperating with the 4 walls of the openings 54. Extending transversely through the valve 55 between the collars 56 and 57 is an opening 61, and extending transversely through the valve 55 between the

collars

53 and 59 is an opening 62, the openings 61 and 62 both being in uid communication with an elongated opening 63 also provided in the valve member 55. Extending transversely, also, to the valve member 55 and in fluid communication with the opening 63 is another opening 64. On the left end of the valve block 51, from the view of Figure 7, there is provided xedly mounted a suitable end cap 65 having the centermost portion thereof spaced substantially from the block 51 as illustrated. In engagement with the underside of transversely extending portions of the end cap 65 is a retainer 66 which is circular in cross-section and which is provided with a generally circular aperture centrally therein through which the valve member 55 slidably extends. Against the retainer 66 there is disposed one end of a spring 67, the opposite end of whichabuts against a suitable retainer 68 which is biased thereby into engagement with the collar 56 on the valve member 55 and a suitable shoulder formed in the block 51. The right end of the valve member 55 in the View of Figure 7, is iixedly connected, for example by threads, to a pin 69 which forms part of an electro-magnetically responsive armature (not shown). Disposed about the armature so as to eieet longitudinal reciprocation of pin 69 are windings 71 and 72. One end of each of the windings is grounded, the non-grounded end of winding 71 being connected to a contact R while the non-grounded end of the winding 72 is connected to a contact L. To control the euergization of the windings 71 and 72 there is provided a single pole, double throw switch 73 having a contact member 74, pivotally mounted at 75, and adapted to be moved into engagement with the contacts L and R selectively. To the contact arm 74 is connected one terminal of a suitable source of energization, such as a battery 76, the opposite end of Which is grounded. l

The spring 67 normally biases the valve 55 to the position illustrated in Figure 7. In this position it will be seen that the cylinder 1 has both ends thereof in communication with the return port 52. As a result, no pressure is applied to either end of the cylinder 1.

Assuming that the structure is initially in the position illustrated in Figure l, and that the right end, from the View of that figure, of the rod 9 is connected to a window raising mechanism in an automobile, if the contact arm 74 is moved into engagement with the contact R the battery 76 will eiect energization of the winding 71. The structure is arranged such that the pin 69 is thereby moved to the left, from the view of Figure 7, moving the valve member 55 to the left and thereby compressing the spring 67. Fluid under pressure will then pass from the inlet port 53 between the collars 57 and 58 and through the port 47 and the conduit means 45 to the opening 5 in the cylinder flange 3. it should be noted that in this position of the valve member 55, the collars 57 and 58 prevent flow of fluid from port 53 to the return port 52. As a result, uid under pressure ows through the port 5 into the opening 6 in the cylinder flange 3 and against the underside of the rod 9. Movement of the rod 9 to the right by virtue of this pressure is prevented, however, by frictional engagement of the collar 29 which is tightly frictionally wedged into the opening 34 and into tight frictional engagement with the rod 9. Fluid under pressure, however, Hows about the outer radially facing surfaces of the nut 11 and against the left side, in the view of Figure 1, of the piston 13. inasmuch as piston 13 is slidably mounted upon the rod 9, piston 13 is moved rapidly to the right in cylinder 1 and into engagement with the innermost surface of piston guide 28. The piston 13 forces the piston guide 28, and the collar 29 which is disposed in engagement with the piston guide 28, to the right to the position illustrated in Figure 4 against the bias of the yspring 36. As the collar 29 is moved from the position illustrated in Figure l to the position illustrated in Figure 4-that is to say, as it is moved outwardly of the opening 2x4-'

fire segments

31, 32 and 33 expand to release their tight frictional engagement on the rod 9.

When the

segments

31, 32 and 33 have released their tight engagement with the rod 9, the tuid pressure within the opening 6 in the cylinder flange 3 acts upon the cross-sectional area of the rod 9 causing it to move in the direction indicated by the arrows in Figure 4. As the rod 9 moves toward the right, from the view of Figure 4, the window mechanism attached thereto will operate to move the window toward its closed position. It will be obvious that the stroke of the device is longer than the required travel of the attached Window mechanism; as a result, when the rod 9 attains a position relative to cylinder 1 approximating that illustrated in Figure 5, the window will be fully closed. As long as the contact member 74 is maintained in engagement with the contact R, pressurized fluid will be forcing the rod 9 toward its relative position illustrated in Figure 5, suitable mechanism (not shown) being disposed in the uid pressure supply mechanism to prevent attainment of excessive pressure.

When the contact member 74, which is normally biased to the full line position illustrated in Figure 7, is released, it will move away from the contact R to the full line position of Figure 7. As a result, the electrical circuit through the Winding 71 is interrupted and the spring 67 will effect movement of the valve 55 (and the pin 69- electro-magnetically responsive armature assembly) to the position illustrated in Figure 7. As previously described, when the valve 5S is in the position shown in Figure 7, pressurized uid is prevented from flowing to the cylinder 1 and the uid within the cylinder 1 is permitted to drain to the sump through the return port 52. As this uid under pressure is released from the cylinder 1, the spring 36 is permitted to expand and-operating against the ledges 35 on the

segments

31, 32 and 33 forces these segments (which form collar 29) into the tapered aperture 34, as illustrated in Figure 5. As the collar 29 is forced into aperture 34 the inner curved surfaces 3112, 32b and 33h of the segments frictionally engage the rod 9; the weight of the window mechanism, biasing the rod 9 to the left in Figure 5, acting together with the spring 36, effects the tight engagement of the collar 29 with the rod 9 which is, therefore, maintained in its raised position with the window mechanism fully raised. The collar 29, therefore, will hold the rod 9 in the position illustrated in Figure 5 until the lowering mechanism is operated.

To lower the Window mechanism-that is to say, move it from the position illustrated in Figure 5 to the position illustrated in Figure l-the contact arm 74 is moved into engagement with the Contact L to effect the energization of winding 72. As a result of this energization, the pin 69 is moved to the right, from the view of Figure 7, and forces the valve 35 to the right against the bias of the spring 67. Fluid under pressure is, therefore, permitted to flow through the inlet port 53 and between the collars 57 and 53 on the valve S5 through the port 4S and the conduit means 46 to the opening S the cylinder liange 3. inasmuch as the tube 1S is in fluid communication with the opening 8, uid under pressure will fiow through the tube 18 and into the openings 26 and 27 in the body 24. This pressurized fluid will then proceed into the left portion of the opening in the body 24-and, acting on the innermost surface of the piston guide 2S, will force the piston guide 28 tothe right as shown in Figure 6. As a result, guide 2S will simultaneously force collar 29 to the right, outwardly of the tapered opening 34, so that the

segments

31, 32 and 33 will be permitted to separate and release the rod 9.

Simultaneously, pressurized fluid will operate on the piston 13 to force it into engagement with the washer 12,

6 mounted on` the rod 9, and the rod 9 will be moved` to.-

Ward the left in the view of Figure 6 by virtue of the weight of the window mechanism and by virtue of the force applied to the washer 12 by the piston 13 against which the pressurized fluid acts.

After the rod 9 returns to the position relative to the cylinder 1 which is illustrated in Figure 1, the contact member 74 may be released so that further application of pressurized fluid to the cylinder 1 is terminated. The contact member 74 will move to the position to which it is biased as indicated by the full line position in Figure 7. Thereupon, the winding 72 will be deenergized and the valve will be returned to the position illustrated in Figure 7 by the spring 67, the armature-rod 69 assembly being moved to the position also illustrated in that figure with the valve member 55. Both ends of the cylinder 1 are vented to the return port 52 through the opening 63 in the valve 5S. It should be similarly noted that upon subsequent movement of the rod 9 toward raised position and fluid which remained in the upper portion of the cylinder 1-that is to say, to the right of the piston 13 in Figure 1-is readily returned to the sump through the return port 52 by virtue of the openings 62, 63 and 641 in the valve member 55 as the piston 13 begins its movement toward piston guide 28.

Discussing now the modification of the structure illustrated in Figure 8, there is disclosed therein the cylinder 1 suitably connected at 2 to the cylinder flange 3; Cylinder 1 is in fluid communication with the opening 6, which is in turn in fluid communication with the port 5. As previously described, the flange 3 is further provided with an opening 8 which is in uid communication with the tube 18. Disposed within the cylinder 1 is a rod 9' which differs from the rod 9 only in that it is provide'd at its left end with a greater portion of reduced diameter. Near the left end of the rod 9 there is provided a shoulder 87 against which is positioned a washer S8', comparable to the washer 12 shown in Figure 1. Disposed in engagement with the washer 88 is a piston 39 having a circular aperture extending therethrough which surrounds the associated portion of the rod 9'. The outer periphery of the piston 89 is circular and is disposed in engagement with the inner circular walls of the cylinder 1, suitable sealing means 91 being provided between piston 89 and thecylinder 1. Threaded upon therod 9 is a nut 92, comparable to the nut 11 in Figure l. It will be seen that the piston 89 is thereby fixed to the rod 9. The other portions of the operative structure comprising the embodiment partially shown in Figure 8 are the same as that illustrated in Figures 1 through 6. As a result, when the contact member 74 is moved into engagement with the contact R, and pressurized fluid is admitted into the opening 6 in the cylinder flange 3, the rod 9 will be forced upwardly--to the right in Figure 8`and carries the collar 29 out of the opening 34 in the body 24. The other operation of the modification illustrated in Figure 8 is the same as previously described in connection'with the embodiment illustrated in Figures l through 6. It will be appreciated by those skilled in the art that the modification illustrated in Figure 8` is primarily operative when the pressure applied to effect movement of the rod 9 is substantially high and/or the included angle 34a, dened by the sides of the opening 34 (and, therefore, the angle formed by the externally facing surfaces of the

segments

31, 32 and'33 when they are positioned in the opening 34) is relatively small.

Turning now to a consideration of the embodiments of the present invention illustrated in Figures 9 and 10, there is disclosed therein structure useful with control apparatus of the type illustrated in Figure 7. As shown in those figures, there isprovided a cylinder 1 having a circular internal bore therein which extends throughout the length of the cylinder 1, as previously described. Cylinder 1 is fixedly mounted at 2 byv suitable means` to r an end cap 93. Cap 93 has a circular openingl 94 7 therein which extends partially through the cap 93, portions of the opening being disposed in xed engagement with the associated end of the cylinder 1. The opening 94 in the cap 93 is iu fluid communication with a port 95, adapted to be connected to the tubing or.

conduit means illustrated in Figure 7. Cap 93 is further provided with an extension at 96 by which the cap 93 may be fixedly mounted, for example, to the door of an automobile. The opposite end of the cylinder 1 is xedly attached by suitable means, indicated by the numeral 97, to an end cap 93 having a generally circular aperture 99 extending partially therethrough, into which the end of the cylinder 1 extends. A port 101 extends radially through one side of the cap 98 and is in fluid communication with the opening 99. Extending longitudinally through the outer wall of the end cap is a circular opening 102 which closely 'receives the sides of a control rod 103. The portion of the end cap 98 surrounding the circular aperture 102 therein is provided with suitable sealing means, as clearly indicated in the drawing.

The right end, in view of Figure 9, of the control rod 103 is adapted to be attached to a suitable window controlling mechanism. This control rod 103 is generally circular in cross-section throughout its length and is adapted to be reciprocated within the cylinder 1. Slidably disposed upon one portion of the control rod 103 is a piston 10dL which has a circular aperture therethrough, the sides of which are disposed in engagement with the control rod 103. The outer periphery of the circular piston 104 is disposed in engagement with the walls of the cylinder 1, as illustrated. The left surface, from the view of Figure 9, of the piston 104 is disposed in engagement with a collar 105 which comprises a generally cylindrical outer surface disposed in engagement with the walls of the cylinder 1, collar 105 further being pro vided with a tapered opening 106 extending therethrough. The included angle 106a defined by the tapered walls of the opening 106 is preferably of the order of approximately y13 degrees or less depending upon the hydraulic fluid pressures employed. The collar 106 is formed of an expandable nature and, as previously indicated, the outer wall thereof frictionally engages the associated wall of the cylinder 1; the inner, tapered walls forming the opening 106 frictionally engage a complementary tapered portion 107 integrally formed on the control rod 103. The left end portion of the collar 106 is provided with a depending ledge 108 which serves as a retainer for one end of a spring 109 disposed between the ledge 108 and the inner wall of the cylinder 1. The spring 109 is disposed in abutment with the left edge of the collar 106, in the view of Figure 9, the opposite end of the spring 109 being disposed in engagement with the right end of a liange 111. The liange 111 is circular in crosssection, and the outer wall thereof being disposed in engagement with the walls forming the opening through the cylinder 1. The flange 111 is further provided with an inner, circular opening extending therethrough in which the left end of the control rod 103 is disposed. Suitable means 112 are provided which lixedly attach the flange 111 to the control rod 103.

The operation of the modification of the present invention illustrated in Figures 9 and l0 will now be described. Figure 9 discloses the structure in its lowered position. When it `is desired to move the mechanism and the window mechanism attached thereto to a Lraised position, the contact member 74 illustrated in Figure 7, is moved into engagement with the contact R. As previously described, this effects the liow of pressurized fluid through the conduit means 45, therefore, through the port 95 and into the opening 94 formed in the end cap 93. This pressurized fluid will thereby engage the left end of the flange 111 and the control rod 103. The tapered portion 107 `of the control rod 103 will thereby be moved to the right together with the rod out of the opening 106. As

a result, the expandable collar will be permitted to contract somewhat to sufliciently release from the walls of the cylinder 1 for a movement of the collar 105. The movement to the right of the control rod 103, and the flange 111 attached thereto, will elfect movement in the same direction of the expandable sleeve or collar 105 by virtue of the connection between the ange 111 and the collar105 provided by the spring 109. ln addition, the ledge 10S on the sleeve 105 may also be engaged with the to effect movement to the right of the sleeve 1 it should also be noted that the piston 104 will likewise be carried to the right by virtue of its erigagement with the sleeve 105 and rod 103. As previously described, the stroke of the mechanism is designed such that it is longer than the actual closing movement required of the attached window mechanism so that the hydraulic pressure will move the Window to closed position before the left end of the control rod moves completely beyond the right end of the cylinder 1. So long as the contact member 74 is maintained in engagement with the contact R, as previously described, fluid under pressure will be applied to the llange 111 and the control rod 103 forcing the assembly to the right. Upon release of the control member 74 and its movement to the neutral position illustrated by the full lines in Figure 7, liuid in the cylinder 1 is vented to the return port 52, as previously described. The weight of thc window mechanism and the bias of spring 109, will, therefore, force the control rod 103 toward the left, in the view of Figure 9, whereby the portion 107 of the control rod 103 will move into the opening 106 in the collar 105 to substantially the position relative to collar 105 illustrated in Figure 9. In this position, the wedging action of the portion 107 on the expandable sleeve 105, and the frictional engagement of the outer periphery of the collar 105 with the walls of the cylinder 1, is such that the window mechanism will be maintained in its raised position.

To lower the window mechanism, contact member 74 is moved into engagement with the contact L. As previously described, this will elfect the application of fluid under pressure through the conduit means 46 to the port 101 in the cap 98. This pressurized tluid will llow into the opening 99 in the cap 98 and apply a force to the outwardly facing surface of the piston 104 which is in a direction to move the piston 104 to the left. As shown in Figure 10, the piston 104, therefore, forces the collar 105 toward the left against the bias of spring 109 and thereby effecting relative movement of the portion 107 of the control rod 103 to the larger end of the opening 106 in the collar 105. As a result, the tight frictional engagement between the collar 105 and the wall of cylinder 1 is released and the combined effect of the weight of the window mechanism together with the force applied to the portion 107 by the piston 104 effects movement of the control rod 103 back toward its lowered position illustrated in Figure 9. The pressurized fluid will continue to act against the piston 104 in a direction to effect release of the collar 105 so long as the contact member 74 is maintained in engagement with the contact L. If this engagement is maintained until the window mechanism is fully lowered, no further movement of the control rod 103 will result. Upon release of the contact member 74 and its return to the full line position illustrated in Figure 7, the device will assume the position shown in Figure 9 and both ends of cylinder 1 will be vented, as previously described, to the return port 52.

Turning now to a consideration of the embodiment of the present invention partially illustrated in Figure ll, there is disclosed therein a cylinder 1 xedly mounted at 2 to the end cap 93. Disposed within the internal bore in the cylinder 1 is a longitudinally movable control rod 113 which is generally circular in cross-section throughout the greater portion of its length, the right end of the rod 113-from the viewv of Figure -1 l-being connected to a suitable window operating mechanism. Attthe left end of the control rod 113 there is provided a suitable stop washer 114 adapted to abut against a pistion 115. The piston 115 has a generaliy circular outer wall in engagement with the walls of the circular inner bore in the cylinder 1, the piston 115 having a circular aperture therethrough which closely receives the associated portion of the control rod 113, the piston 115 being slidable -upon this associated portion of rod 113. Rod 113 is further provided with a cam portion 115 integral therewith and substantially in the shape of a truncated cone. It will be seen that the portion 114 is substantially similar tothe cam portion 107 formed on` control rod 103 and illustrated in Figures 9 and l0. Disposed in engagement with the inner wall of the cylinder 1 is an expandable sleeve. 117-substantially comparable to the expandable sleeve 105 in the embodimentof the invention shown in Figures 9 and l0. The` sleeve117 has a tapered opening 118 therein which defines an included angle i18n of the order of 13. The outer portion of the sleeve 117 is adapted to frictionally engage the inner walls of cylinder 1 while the walls dening `the opening 118 in sleeve 117 are adapted to frictionally engage the cam portion 116 on the-control rod 113. Disposed in engagement with the right end of sleeve 117, from the view -of Figure l1, is a spring 119, the opposite end of which abuts against a stop member 121 integrally formed on the rod 113. Also disposed in abutment with the stop member 121 is one end of an oppositely dispos-ed spring 122, the opposite end of which engages an expandable sleeve 123 comparable to the sleeve 117. lt will be seen that the control rod 113 is provided with a cam portion 124 in the form of a truncated cone and comparable to the cam portion 116 previously described. The sleeve 123i is provided with a tapered opening 12S, the sides or which dene an included angle 125e of approximately 13. Disposed in engagement with the sleeve 123 is a piston 126 having a cylindrical outer wall in engage-ment with the inner opening in cylinder 1 and having a circular inner opening closely receiving the associated portion of the control rod 113, the piston 126 being slidable upon such associated portion of the rod 113. It will be manifest to those skilled in the art that the right end of the cylinder 1 would be received within the end cap 98 in exactly the same manner as illustrated in Figures 9 and 10.

The modification of the present invention illustrated in Figure l1 is shown in its lowered position. To raise the window operating mechanism attached to tne control rod 113, the contact member 7d would be moved into engagement with the contact R whereupon pressurized uid would be applied against the left end of the piston 115. This piston is arranged to have a surface at its left end which is greater in area than the left end of the control rod 113. As a result, piston 115 will slide to the right along the control rod 113 forcing the sleeve 117 to the right against the bias of spring 119. The control rod 113 would thereby be released from the tight engagement with the sleeve 117 and hydraulic pressure operating upon the left end of the control rod 113 will force it to move to the right toward its raised position. As this movement is accomplished, the piston 115 maintains the sleeve 117 released from tig-ht engagement with the cam portion 116, and the spring 122 and stop means 121 force the collar 123 and piston 126 in the direction of movement of the control rod 113. Upon release of the Contact member 74, the valve member 55 will return to the piston illustrated in Figure 7 and, as previously described, both ends of the cylinder 1 will be Vented to the return port 52. The weight of the window operating mechanism and spring 119 will then force the cam portion 124 on the control rod 113 into tight frictional engagement with the sides of the opening 125 ,in the expandable sleeve 123 whereupon this sleeve will '1'0` prevent movement ofthev controlrod 113 towardv its lowered position.

To effect movement of the Window operating mechanism to its lowered position, the contact member 74 is moved into engagement with the contact L whereby pressurized uid would pass intothe cap. 98l vassociated with the cylinder 1 and. through thetborein the cylinder 1 into engagement withthe-right hand: surface of the piston 126. The piston 126 will thereby be moved toward the left forcing the, expandable sleeve 123 toward the left against the bias of the spring 122. As a result, the control rod 113 will be released from its tight frictional, wedging engagement with the sleeve 123 and the weight of the window operating mechanism acting together with a force applied by the piston 126 to the cam portion 124 would effect movement of the control rod 113 to its lowered. position. Again,VV upon release of the contact member 74both ends ofthe cylinder 1 will be vented to the return port 52, and` the collar 123 will be `forced into the position relative to the cam portion 124 which is illustrated inFigure l1. It will be seen that the modication of Figure. 1l provides for positive locking of the control rod; 113 in both directions of its movement, the expandable collars -or

sleeves

117 and 123 cooperating with the associated. cam portions on the rod 113 to positively prevent movement of the control rod in -either direction until the desired sleeve or collar- 117 or 123 is released by the application of hydraulic pressure.

lt will be obvious to those skilled in the art that the embodiment of the .present invention shown in Figure 1l is best adapted for use where the hydraulic pressure used is relatively high and/or the included angles 118e: and 125a are relatively low.

It will be seen that the device of the present invention provides simple and economical means for raising and lowering the control mechanism, the means including wedging type locking means which positively prevent movement of the control rod until released by the application of hydraulic pressure. It should also be noted that the present invention includes the provision of wedging type locking means which prevents any longitudinal movement of the control rod in either direction until released by the application of hydraulic pressure. It will further be obvious that `all of the embodiments of the invention have a `control rod which may be moved upwardly and downwardly at will and stopped in any position intermediate its fully raised or lowered position as may be desired.

While l have described my invention in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not by way of limitation and the scope of my invention is defined solely by the appended claims which should be construed as broadly as the prior art will permit.

I claim:

l. In a hydraulically operated control mechanism, housing means, means defining an elongated opening in said housing means, a control rod in said opening adapted for longitudinal movement therein to eifect a control function, lock means comprising a longitudinally tapered expandable collar adapted to wedgingly engage between said rod and said opening defining means to prevent movement of said control rod in at least one longitudinal direction, said lock means being constructed and arranged to permit movement of said ro'd in the one longitudinal direction upon movement of the lock means to a predetermined position relative to said rod, a iirst piston disposed in said opening upon said rod for movement relative to said rod adapted to effect movement of said lock means to said predetermined position whereby said rod is released therelfrom, and a second piston disposed in said opening upon said rod for movement relative to said rod in response to hydraulic pressure adapted to engage said first piston and effect its movement to lock releasing position,

2. In a hydraulically. operated control mechanism, housing means, means dening an elongated opening in said housing means, means defining a tapered opening in said housing means in communication with one end of said elongated opening, a control rod in said openings adapted for longitudinal movement to elect a control function, lock means in said tapered opening comprising a plurality of tapered segments each including an outer surface adapted to complementarily engage said tapered opening defining means and an inner surface adapted to complementarily engage said control rod, means biasing said segments into said tapered opening and into tight engagement with said control lrod whereby said rod is held from longitudinal movement in at least one direction, and means for moving said segments outwardly of said tapered opening against the bias of said biasing means comprising a rst piston disposed on said rod for movement relative thereto adapted to engage sai-d segments and a second piston in said elongated opening disposed on said rod for movement relative thereto in response to hydraulic pressure constructed and arranged to engage said first piston and effect its movement to lock releasing position.

3. The device defined in claim 2 in which means are provided to supply selectively hydraulic fluid to both end portions of said elongated opening to eiect movement of said pistons.

4. The device defined in claim 2 in which means are provided to supply selectively hydraulic fluid to both end portions of said elongated opening to effect movement of said pistons comprising electro-magnetically controlled means constructed and arranged to supply hydraulic fluid to either of said end portions and further constructed and arranged to vent simultaneously both of said end portions to low pressure.

References Cited in the tile of this patent UNITED STATES PATENTS 1,073,403 Dalton Sept. 16, 1913 1,956,110 Turrettini Apr. 24, 1934 2,030,986 Havill Feb. 18, 1936 2,259,815 Greve Oct. 2l, 1941 2,325,775 Horton Aug. 3, 1943 2,339,291 Paulus et al Jan. 18, 1944 2,632,425 Grover Mar. 24, 1953 FOREIGN PATENTS 81,002 Austria July 26, 1920 367,075 Italy lune 14, 1939 397,512 Great Britain Aug. 22, 1933 882,422 France Mar. l, 1943 884,858 France May 8, 1943 UNITED STATES PATENT @EETCE CERTIFICATE 0F 'CQRRECHN Patent No., 2,845,902 August 5, 1958 5 Edward (L Anderson It is herebr certified that error appears in the-printed specification of the above 'numbered patent requiring correction and that the said Letters Patent should read as corrected below,

Column 9, line 69, for "pist-on" reed mpoetonm.,

Signed and sealed this 14th day of October 19.553.,

(SEAL) Attest:

KARL Amm EoEEET c. WATsoN Attesting Gcer Commissioner of Patents