US1920272A - Shock absorber - Google Patents

Description

iTE D STATES ren* oFFcE snoonnesonnne Ralph F. Fee; Buffalo, PLY., assigncr to Honde V Engineering Corporation, Buffalo, N. Y., a Corporation of New York Application March '5, 1931. S mine. 520,218 :8 Claims. (Ci. 183- 69.)

This invention relates to a hydraulic shock absorber and has the objectjtoprovide an ab-. sorber of thischaracter which issimple in construction, low in cost of nanufacture and eicient (in operation.

In the accompanying drawing: v

Fig. 1 is a Vertical longitudinal section of a shock absorber embodying my improvements.

Figs. 2, .3 and 4 are Vertical transverse sections of the same' taken on the correspondingly numbered lines in Fig. 1.

In the following description similar characters of reference indicate likeparts in 'the several figures of the drawing.

The. bodyof the absorber comprises a cylindrical wall 10, the rear end of which is closed by a transverse head 11 and provided with later ally projecting attaching lugs 12 by which the body may be connected with one of the relatively movable members between which the shock is to be absorbed. sumed that the lugs 12 are connected with the frame or body of an automobile or motor car which is mounted by a spring suspension system on the aXles of the car and is movable toward andfrom the axle while the car is running over roadways. r g

This cylindrical wall, the rear head and attaching lugs are made integrally by casting same of iron or the like.

On its inner ,or front side the rear head 'is provided* with a rear bearing or pilot pin 13 which has its periphery con'centrio with the bore of the cylindrical wall and is preferably connected'with the rearheadby electric Welding, as

shown in Fig. 1.'

To the front edge of the peripheral Wall 10 a front transversehead 1 is secured: by a screw joint 15 or other suitable means and provided 'with a tubular neck 16 which is concentric with the wall 10 and opens at its rear end toward the space within the body while it`s` -front end'lias an r inwardly projecting flange 17 which is" bevelled on its rear side`, as shownat 18, in Fig. 1. l 'The -front wall and its nock are also preferably constructed of cast metal such as'i ron;

Within the upper part of the cylindrical space,

enclosed by the housing composed of the Circular wall 10, rear head 11 "and front head 14, is arranged a partition 19 which divides this space` In the present case it will be as chamber required. This partition is preferably'constructed of cast steel and comprises a segmental'intermediate web 22'which is equal in length to the distance between the front and rear walls and engages the inner sides of the same and has an inner bearing face 23 which is concentric with the axis of the working'chamben' and two flanges 24 projecting radially outward from opposite ends ofthe Web 22 and .having outer curved faces 25 which are concentric with; the bore of the wall 10 and engage with the inner l side of the same.

This partition may be held in place within the body any suitable mannerbut preferably by mea s of two metal plugs 25 inserted through radial. openings 27 in the wall 10 and welded by an electric 'current or 'by a flame' to the outer faces 25 of the partition fianges and to the peripheral wall so as to render these parts integral.

Within the working chamber is arranged a piston which oscillates about an axis concentric with. this chamber, extends from the front head to the rear head thereof; and comprises a cylindrical. hub 28 engaging its upper part with the curved underside 23 of the partition, and awing 29 exterding radially from the hub and engaging its outer end with the curved bore of the working chamber, as shownin Figs. 2 and 3. The rear end of the hubof the piston is provided with a bearing recess 30 which receives the bearing pin 13 of 'the rear wall and the front end 'of this hub is connected with the rear end of an operating shaft 31` Which extends forwardly through the tubular neck of the front wall. This shaft is journaled in a bearing sleeve 32 which is secured with a tight fit in the inner end of the neci 16 of the front wall. Leakage of resistance V fluid through the' joint between the operating shaft and the neck of the front wall' is prevented by an annularpacking 33 arranged between this shaft and said neck and engaging its front end with its bevelled face 18 on the rear side of the flange 1'7 and its rear end with the bevelled face 34 on the front end of the bearing sleeve 32, as

shown in Fig. 1.

When the front head 14 is screwed into assembled position on the wall 10 the packing willbe compressed between the sleeve and the fiange. V

'To the front end of the operating shaft' is secured an operating arm or lever which is connected with the other of the two members may be effected in any suitable manner butpreferably in accordance with my invention which is constructed as follows:

The hub 36 of the operating arm which sur rounds the front end of the operating shaft is provided in its bore with a plurality of longitudi- 'nal grooves 37 which are half-round in cross ating shaft form rearwardly tapering surfaces.

' Into each of the longitudinal openings thus formed between a groove 37 in the operating arm and a groove 38 in the operating shaft is inserted.

a straight longitudinal key or pin 40 and after such ,insertion this pin is exposed to a Welding heat'derived either 'from an electric current or otherwise so that the metal of the pin fiows and fills the grooves andis fused to the lever 35`and shait 31.

By this Welding means the operating lever is anchored on the operating shaft so that these parts are held against torsion relative to one another, and the same are also reliably interlocked and incapable of being displaced by either a pulling or pushing on ,the same in a direction lengthwise of the axis of the operating shaft and arm.

Means are provided for pernitting the re- *sistance liquid to flow through the piston while the wing of the same is moving to the low from the high eompression end of the working Chaniber` which direction is opposite to that indicated by the 'arrowassociated with the piston in Figure'2, but while the piston is moving in the opposite direction the resistance liquid is prevented from flowing through the piston thereby causing the resistance liquid to offer a greater resistance to the movement of the piston during ;rebound of the spring system of the vehicle than during the compressing action of the same. v

Although various means may be employed for accomplishing this purpose those shown in the drawing are satisfactory' and consist of a byv :pass port 42 formed in the wing of the piston and extending from one side to the other, and a leaf ,Valve 43 secured to the wing and adapted to close the -port 42 during the high compression strokes of the piston and to uncover said port during' the ,low compression Strokes of the piston.

In order to permit of regulatingthe resistance which the liquid offers to the movement of th'e piston in the working chamber to suit the load which the shock ahsorber is intended to carry .;regulating means are provided which are constructed as iollows:--

v Formed in the concave or underside of the partition is a regulating or metering passage 44 which extends circumferentially from one end jof the partition to the other and therefore conflow of the .resistance liquid whenever sudden bumps are encountered by the car on the roadway. V

The effective cross sectional area of the regulating passage may be regulated to suit different requirements or conditions by means of a metering or regulating valve 45 movable vertically in a seat 46 formed radially in the central part of the web ofthe partition so as to intersect the adjacent part of the regulating or metering passage. Upon moving the netering valve vertically in its seat the regulating passage may be obstructed more or less and thus adapt the shock absorbing capacity of the'instrument according to the load imposed on the "same, The adjusting movement of the regulating valve is effected by means of an external screw thread 47 on the upper part of the regulating valve engaging with an internal screw thread 48 in the upper part of the regulating valve seat whereby upon turn ing the regulating valve its lower end will extend more or less across the regulating passage. The

regulating valve may be turned for this purpose i latter the requisite extent. This opening is prefi erably utilized for the additional purpose of filling the replenishing chamber or reservoir 21 with a reserve supply of resistance liquid and under normal conditions this filling opening 49 is closed by a screw plug or cover 51.

The valve seat 46 preferably extends from the lower to the upper side of the partition 19 and any leakage of liquidpast the regulating valve due to the pressure against the same in the working chamber will cause such leakage to flow from the inner side of the partition past the joint between the metering valve and the partition into the replenishing chamber. The screw cap or plug 51 which closes the filling opening is preferably utilized as a fastening means for holding said `metering or regulating valve against turning out of position after being adjusted for which purpose the plug51 when in its fully closed position engages the outer end of the valve 45 and clamp the same in place. To further guard against displacement of the regulating valve 45 when the instrument is in use the screw threads of the connection between the regulating valve are of different pitch 'from those Connecting the filler plug 51 with the peripheral wall,` as shown in.

tion, past the regulating valve into the' replen-- ishing chamber by engagement of the filler plug with the outer end of the regulating valve, the inner end of the filler plug isprovided with a bearing boss 52 for engagement with the outer end of the regulating valve which is of smaller diameter than the latter, as shown in Figs. 1 and 3, thereby preventing the filling plug from overlapping the screw joint between the regulating valve and the partition and permitting flow of leakage fluid through the same from the working chamber into the replenishing chamber.

Liquid forreplenishing the loss in the working chamber is supplied to both ends of the latter from' the replenishing chamber or reservoir 21 by replenishing ports 53 formed in ends of the partition and each extending from the replenishing chamber to the uppermost part of' one end of the working chamber and each having: a valve seat'54 which faces toward the working chamber and a check valve 55 arranged in said port and adapted to move toward and from said seat for closing and opening the same. As the piston moves away from one of the check valves 55 the, latter will open and permit resistance liquid to be drawn from the replenishing chainber into the working chamber and upon moving the piston toward the respective replenishing valve the same will be moved into its closed position, so that the liquid in the respective end ofthe working chamber will be subjected to pressure and cause shock to be absorbed.

Any air or gas which may be present in the' to fiow into the working chamber as long as" there is any liquid in the replenishing chamber, and reducing to a minimum the liability of the shock absorber getting dry, as well as prevent the same from getting air bound.

Briefly summing up 'the operation, the body of the shock absorber is secured to a vehicle chassis and the lever 35 is connected with the axle. During passa-ge of the vehicle over ordinary road irregularities the oil may freelyfiow between the high pressure and low pressure sides of the working chamber 20 so that the normal operation of the vehicle spring will not be interfered with., Under abnormal road conditions, should the chassis and axle befsuddenly brought together the piston will swing to the low pressure side of the working chamber and the valve 43 will open to assist the passageway 44 for free flow of oil into the high pressure side of the working chamber. However, when the vehicle spring tends to separate the chassis and axle the piston moves in the opposite direction and the valve 43 will be closed so that the oil can escape from the high pressure side to the low pressure side only through the pasageway 44 and the recoil action ofthe spring will be'retarded and the shock thereof absorbed. The regulating or metering passage 44 being in the form of a narrow groove, introduces surface friction to the,

passage of the oil therethrough which adds materially in gradually softening and absorbing the spring rebound and shock. The resistance to flow is of course readily further adjustable by means of the valve 45.

As the piston swings to one side of the working chamber the replenishing valve 55 at that 'side will be closed but the replenishing valve for the other side of the chamber will open so that such other side will be fully filled with oil for reverse movement of the piston. Any air which may have been entrapped in the working chamber will be driven out to the replenishing chamber through the restricted vent passages 56 and although these vent pasages are open at all times, very little oil will escape therethrough owing to'the resistance so that these air vents will not interfere with the proper operation of will rise and accumulate at the top of the replenishing chamber where they cannot interfere with the proper operation of the device.

I claim asmy invention:

l. A hydraulic shock absorber comprising a housing enclosing a cylindrical space, a partition in said dividing ,said space into a lower scgmental working chamber and upper .replenishing chamber, the underside of said par-` tition'having a segmental bearing surface which is concentric with said Working chamber, a circumferential groove in ,said bearing surface, and a v'erticai valve intersecting said groove, a regulating valve arranged in seat and having screw 7 bh said partition for moving said valve more or lessacross said groove,'

a piston oscillating in said working chamber and having a hub engaging extending s groove, said housing provided'wltha filling pening above said regulating valve and a closure for said filling openin 2. i'i-hydraulic shock absorber 'comprising a housing enclosing cylindrical 'space, a partition in said housing dividing said space into a lower segmentai wor ing chamber and an upper replenishing chamber, the underside of said partition having a segnental bearing surface which is concentric with'said working chamber, a circumferential groove in'said bearing surface, and

a Vertical valves at intersecting said groovea regulating valve arranged in said seat and having screw connection with said partition for' moving said valve more or less across said groove;

a piston osciilating in said working chamber and:

having-a hub engaging said bearing surface and extending across said groove, said housing provided with a filling opening above regulating ,said reguiating valve.

3. A` hydraulic shock absorber comprising a housing enclosing a cylindrical space,` a partition in said housing dividing said space into a lower segmental working chamber and an upper reing valve, and a closure for said opening engagpienishing chamber, the underside of said partition having a segmental bearing surface which is concentrie with said working chamber, a circunferential groove in said bearing surface, and a Vertical valve seat intersecting said groove, a regulating valve arranged in said seat and having a screw connection with said partition for a piston oscillating in said working chamber and having a hub engaging said bearing surface and extending across said groove, said housing provided with a filling opening above said regulating valve, a screw piug closing said opening and engaging said regulating valve, the screw threads of said valve and plug being of different pitches.

A hydraulic shock absorber comprising a housing enclosing a cylindrical space, a partition in said housing dividing said space into a lower segmental working chamber and an upper replenishing chamber, the underside of saidpartitien having a segmental bearing surface which is concentric with said working chamber, a circumferential groove in said bearing surface, and a Vertical valve seat intersecting said groove, a regulating valve arranged in said seat and having a screw connection with said partition for moving said valve more or less across said groove, a piston oscillating in said working chamber and having a hub engaging said bearing surface and extending across said groove said housing being said bearing surface and' moving said valve more or less across said groove,

provided with a fillingopening above said regulating valve, and a screw plug closing said filling opening and provided at its inner end With a boss which bears on said regulating valve and is of smaller diameter than said valve seat.

5. A hydraulic shock absorber comprising a 'housing having a cylindrical wall, a rear head,

and a front head provided with a tubular neck having an inwardly extending fiange at the front end thereof, said housing enclosing a working chamber, a hub extending through said chamber and a piston extending therefrom, a driving shaft for said hub extending through said neck, a bearing bushing within said neck surrounding said shaft and abutting said hub, and packing V between said bushing and said fiange, said front tending therethrough and conmunicating at its' ends with said working chamber at opposite sides of said piston and having its underside closed by said hub, said groove being of rectangular cross-section with its radial walls comparatively close together so that the surface iriction Will interpose retarding resistance to the flow of oil through said groove, and a valve intersecting said groove and being adjustable for controlling the rate of flow therethrough. v

7. A hydraulic shock absorber comprising a housing enclosing a cylindrical space, a partition in said housing dividing said space into a lower segmental working chamber and an' upper replenishing chamber, the underside of said partition having a segmental bearing surface which is concentric with said'working chamber, a piston adapted to oscillate in said working chamber and having a hub engaging said bearing surface, there being a groove between said partition and said hub comnunicating at its ends with 'said working chamber at opposite sidesof said 'said valve in adjusted position.

8. A hydraulic shock absorber comprising a housing enclosing a cylindrical space, a partition in said housing dividing said space into a lower segmental Working chamber and an upper replenishing chamber, the underside of said partition having a segmental bearing surface which is concentric with said working chamber, a piston adapted to oscillate in said working chamber and having a hub engaging said bearing surface, there being a groove between said partition and said hub conmunicating at its ends with said working chamber at opposite sides of said piston, a regulating valve having screw connection with said partition for adjustment of said valve to extend more or less across said groove to control the flow of fiuid therethrough, said' housing having a filling opening in registration with said valve through which said valve is accessible for adjustment, and a closure for said filling opening for engaging said valve to lock said valve in adjusted position, said 'closure having screw threaded engagement with said housing and the screw threading of said closure and of said valve being of different pitch.

RALPI-IF. PEO.

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