Патент USA US2259815код для вставки
Oct. 21, 1941. L. w. GREVE 2,259,815 LOCKING MEANS FOR FLUID MOTORS Filed May 7, 1958 "23 2/ ‘,1aw mm5PR I. W M Y ATTORNEY Patented Oet. 21, 1941 2,259,815 UNITED STATES PATENT OFFICE 2,259,815 ‘ LOCKING MEANS FOR FLUID MOTORS Louis W. Greve, Cleveland, Ohio, assigns: to The 0leveiand Pneumatic Tool Company, Cleve land, Ohio, a corporation of Ohio Application May 7, 1938, Serial No. 206,620 5 Claims. This invention relates broadly to fluid motors, but more particularly to the type of ?uid mo tor used for retracting and lowering the landing gear of airplanes and the like. One object of this invention is to produce a ?uid actuated motor including a pair of tele scoping cylindrical members, with means for automatically locking the motor against acci dental expansion in the event of a i'ailure of the motive ?uid within the motor. Another object of this invention is the pro duction of a ?uid actuated motor equipped with a locking device located within the“ motor and forming a compact and light assembly which is strong, durable and e?icient. In the drawing: . } ‘, (Cl. 121-40) 20 leading inwardly toward the piston 2! and surrounded by the side wall III of a cup-shaped auxiliary piston 3|, which carries a cup-shaped resilient washer 32 held in position by a nut 88. Extending radially throush the side wall ll of the auxiliary piston ll, there are four equally spaced rectangular ori?ces 34 each having a brake shoe 3! radially slidable therein. The in ner wall It of each shoe is laterally concaved and longitudinally tapered to ?t on the tapered peripheral wall is of the extension 28, while the outer end wall 31 of each shoe is laterally con vexed and longitudinally straight to ?t against the inner wall of the cylinder IS. The shoes 15 35 are of an equal length calculated to enable limited axial movement of the auxiliary piston Fig. l is a side elevatio _ view partly in sec II relative to the extension 28. Interposed be tion of a ?uid motor embodying the invention tween the extension 28 and the auxiliary piston and shown in extended position. ‘3|, there is a compression spring 38 constantly Fig. 2 is a view similar to Fig. 1, showing the 20 urging the piston 3i away from the extension 28. motor in a retracted position. In the modi?cation shown in Fig. 4, the piston Fig. 3 is a cross sectional view taken in a plane I25 and its component cup-shaped resilient indicated by line 3-3 in Fig. 1. washer I28 are detachably secured on the inner Fig. 4 is a fragmental side elevational view of cylindrical member I23 by a nut I21. In this a ?uid motor shown partly in section and illus 25 construction the auxiliary piston It! includes a trating a modi?cation of the invention. sleeve 89 having its upper end internally thread Referring to the drawing in which like sym ed to receive a plug Iii by which the cup-shaped bols designate corresponding parts throughout resilient washer I32 is secured to the piston III. the several views, I5 represents an outer cylinder The inner wall I 38 of the sleeve is tapered to having its upper end closed by an integral head 80 fit on the tapered peripheral wall I28 of the It formed with a clevis I‘! for connection to the extension I28, while its outer wall I3‘! is cylin fuselage of an airplane. The head It is pro drical to ?t on the inner wall of the outer cyl vided with a threaded connection or passage it inder III. To enable expansion or the sleeve, through which motive ?uid may be admitted it is provided with a plurality of longitudinal into the upper end of the cylinder I5. 35 slots II leading upwardly from the lower end Screwed on the lower end of the cylinder ii. thereof and each terminated by a hole I! ex there is a bearing member It also provided with tending radially through the upper end portion a passage 20 for admitting motive ?uid into the of the sleeve which is reduced in cross section lower end of the cylinder I5, and carrying pack an inner annular groove 0. Interposed be ings 2i held in position by an adjustable gland 40 by tween the auxiliary piston Ill and the extension nut 22. Telescopically mounted within the outer cylin der I8, there is an inner cylindrical member 21 having its lower end portion protruding there from and terminated by a connection 24 through which the inner member 23 may be secured to the landing gear of the airplane. The other end portion of the inner member 23 carries a piston 25 and a cup-shaped resilient washer 28 secured in position by a nut 21 and mounted within the outer cylinder for slidable ?uidtight engagement I28, there is also a compression spring I38. In practice. to the connecting passages I8 and 20 are attached motive ?uid conveying conduits admitting motive ?uid into the cylinder I5. These conduits are controlled by a suitable valve whereby motive ?uid is admitted into the cylin der it through one passage and free to exhaust through the other. For the purpose of explana tion, let it be assumed that the motor is in ex tended position as shown in Fig. l and that motive ?uid is admitted into the cylinder I! with the inner wall thereof. ' through the passage III while the passage I8 is Referring now more particularly to the in open to exhaust. In this instance, the motive vention, 28 represents an extension of the in ?uid acting on the piston 25 through its com ner member 23 having a tapered peripheral wall 65 ponent cup-shaped resilient washer 18, will ef 2 a,aso,e1s (act the ?uidtight engagement of this washer with the inner wall of the cylinder IS. The motive iluid acting on the piston will also cause the upward telescopic movement of the inner member 23 resulting in the contraction of the 5 resilient washer m to effect its fluid tight en gagement with the inner wall of the cylinder Ill, and drive the auxiliary piston iii until the plug Ill engages the upper end of the extension III. This downward movement or the auxiliary piston motor. During this upward movement, the compression spring 3! acting on the auxiliary piston 3| will maintain it away from the extension a as shown in Fig. 3. in which instance further axial movement of the piston 3| away from 10 Ill and sleeve Ill relative to the extension ill. will cause the inner wall I36 01 the sleeve to be moved out of engagement with the tapered pe ripheral wall I" of the extension I28, thereby relieving the sleeve from its frictional locking the extension 28 is prevented bythe engagement of the brake shoes I! with the peripheral wall engagement with the inner wall at the cylinder HI, and enabling the free downward telescopic 20 of the extension 28 and the inner wall of the movement of the inner cylinder I23. cylinder II. The tension of the spring I8 is In the modi?ed construction above referred calculated to cause only a slight radial thrust of 15 thereto. it will be understood that the radial the shoes 35 on the inner wall of the cylinder thrust resulting from the expansion of the sleeve II, which radial thrust does not materially afll is acting practically on the entire peripheral feet the free telescopic movement of the inner inner wall of the cylinder H5, enabling the sleeve member II. to be made of metal having a smaller coe?lcicnt After the‘inner member 28 has been moved go of friction than that of the brake shoes 35, with upwardly within the cylinder II, its return stroke out affecting the locking emoiency of the sleeve. e?ecting the expansion of the motor by any In practice, this sleeve is preferably made of forces other than that of the motive ?uid adsofter metal than that of the cylinder Hi, there mitted into the cylinder lb'through the passage by preventing any possible scoring or scratching II, is prevented by the locking mechanism in- 25 of the inner wall of the cylinder. cluding the shoes 35. For instance when the Although the foregoing description is neces inner member 23 is subjected to an axial pull sarily of a detailed character, in order to com tending to e?ect the expansion of the motor, pletely set forth the invention it is to be under the extension 28 will tend to move away from stood that the speci?c terminology is not intended the auxiliary piston 3|, causing a wedging ac- 30 to be restrictive or con?ning and it is to be tur tion between the taper wall 29 and the shoes ther understood that various rearrangements of 35 eil'ecting the radial thrust of the shoes against parts and modi?cations of structural detail may the inner wall of the cylinder II, which thrust be resorted to without departing from the scope is suillcient to prevent the outward slidable moveor spirit of the invention as herein claimed. merit of the inner member 23. The extent of 35 Iclaim: the radial thrust oi’ the shoes 35 against the 1. In a device of the character described, a inner wall of the cylinder II is proportional to pair of telescoping cylindrical members, passages the extent of the axial pull to which the inner admitting motive ?uid into the outer member for member 23 may be subjected, thereby prevente?ecting the telescopic movement of said mem ing any noticeable expansion of the motor ir- 40 bers, a sleeve between said members capable oi’ respective of the load carried by the inner memexpansion into frictional locking engagement her a. with said outer member. and interengaging When it is desired to eiIect the expansion of means on said sleeve and inner member auto the motor. the motive ?uid may be admitted into matically effecting the expansion of the sleeve the upper end of the cylinder l5 through the 45 upon initial movement of said inner member in connection It, while the connection 20 is opened one direction by pulling forces to which said to exhaust. In this instance, the motive fluid inner member may be subjected. will first act on the cup-shaped resilient washer 2, In a device of the character described, an 32 to effect its ?uid tight engagement with the outer cylindrical member formed with a sub inner wall of the Outer cylinder li- The motive so stantially smooth inner wall, an inner cylindrical ?uid acting on the auxiliary piston ll will drive member slidable within said outer member, pas and maintain it in the release position relative to sages adlnjttlng motive ?uid 1111.0 said outer mem. the shoes 35. In other Words. the 911111181’! pisbar for e?ecting the slidable movement of said TDD 1| will be moved from the Position Shown ‘in inner member, a brake carried by the inner mem Fig- 3 t0 the Position shown in Fig- 1- thel'eby on her including a sleeve capable of expansion into 084151118 the 8119-1 movement of the locking shoes frictional engagement with the inner Wall of the 35 from an Operative Position 111150 in hmpel‘ative outer member for preventing said slidable move position relative to the telescopms cylindrical merit in one direction, and means included in said members ‘5 and 13- With the auxiliary Piston brake automatically e?ectlng the expansion of II engaging the upper end 01' the extension 25- 50 said sleeve upon movement of said inner mem the action 01 the mimve mud on the auxiliary bet in said one direction by forces other than that piston Ii is transmitted to the inner member 23 o! the motive ?uid admitted into said outer for effecting its outward movement resulting in member. theInexpansion of the motor. the modi?ed construction shown in Fm 4, 65 pair 3. of In telescoping a device ofcylindrical the character described, a . . members, passages a. pull exerted on the inner member ill will. dmmm t1 mud to th _ due to the engagement of the tapered mating suran 8 mo V6 in 8 Outer membel faces I28 and I36. cause the expansion of the e “ting the teleswpmg mwemem °1 said mam’ sleeve 39 and the consequential frictional en“'3' an exp'msible sleeve between said members gagement or the sleeve's, outer wall "1 with the 70 movable friction creating positionmovement therebe tween forinto preventing the telescoping the cylinder Hi, thereby prevent of the inner member in one direction, and a inner wall of wedge on said member automatically moving said lag outward telescopic movement of the inner the motive ?uid is admitted sleeve into friction creating position upon initial member I23. when of the cylinder HI through into the upper end movement of said inner member in said one di 75 the connection, I it, it will act on the cup-shaped 2,959,815 rection by forces other than that oi the motive ?uid aforesaid. 4. In a device of the character described, a cylindrical housing, a member within said hous ing having one end projecting therefrom, said housing and member being capable of relative slidable movement, asleeve carried by said mem ber capable oi’ expansion into frictional locking engagement with the inner wall or said housing for preventing the slidable movement or said member in one direction, and means operatively associated with said sleeve automatically eil'ect ing the expansion thereof upon initial movement 01’ said member in said one direction by pulling forces to which said member may be subjected. 5. In a device of the character described, a cylindrical housing, a member within said hous 3 in: having one end projecting therefrom, said housing and member being capable ‘of relative slidable movement, a main and an auxiliary pis ton on said member the former stationary there on and the latter capable oi’ limited axial move ment relative thereto,- passages through said housing for admitting motive ?uid to one or the other of said pistons for eiiecting said relative slidable movement, an expansible sleeve carried by said auxiliary piston capable oi’ frictional en gagement with said housing for preventing slid able movement in one direction of said member relative to said housing, and a wedge on said member e?'ecting the operative engagement of said sleeve upon axial movement of said member in one direction relative to said auxiliary piston. LOUIS W. GREVE.