US1291016A - Fluid-cushion device for automobiles. - Google Patents

Description

c. s. KEL LOGG.

FLUID CUSHION DEVICE FOR AUTOMOBILES.

' APPLICATION men APR. 16. 1914. 1,291,016. Patented Jan.14,19 19. 3 SHEETSSHEE[I INVENTO/i ClzarZes Snowlfllo D VI TIIESSES 9 3 .4 TTORNEYS C. S. KELLOGG.

FLUID CUSHION DEVICE FOR AUTOMOBlLES- APPLICATION FILED APR. 16. 1914.

Patented J an. 14, 1919.

3 SHEETS-SHEET 2- WI TNESSES i p INyENTOR C. izafles Snow/111922 To all whom it may concern:

1 UNITED STATESPATENT oFFIcE.

CHARLES SNOW KELLOGG, OF NEW YORK, 1 \T. ASSIGNOR OF ONE-HALF TO HARRY I.

' BERNHARD, OF BROOKLYN, NEW YORK.

FLUID-CUSHION DEVICE FOR AUTOMOBILES.

Specification of Letters Patent. Patented J an. 14, 1919.

Application ifiled April 16, 1914. Serial in. 832,150.

Be it known that I, CHARLES S. KiiLLocc,

a citizen of the United States, residing at the This-invention is a fluid spring for' use on vehicles generally, although it is adapted,

' more particularly, for motor-driven vehicles.

It may be, and preferably is, employed in connection with mechanical springs of one form or another, but in some instances my fluid spring is employed to the exclusion of, or as a substitute for, the mechanical spring, or can be-used as a shock-absorber by attaching one part to the body and the other to the aXle.

The purposes of the invention are, first,-to utilize liquid and air in such manner that the jar and vibration on the vehicle body, due to the contact of the vehicle-wheels with obstacles and depressions in the road surface, will be communicated to a-limited extent only to said body, special provision being made for taking care of or absorbing the recoil of the spring, which recoil immediately follows a compression of the spring and which recoil imparts a more or less violent shock to the car body dependent in most cases upon the extent of compression of the" spring; second, to absorb the recoil due to the return to normal. position of the moving parts of the fluid spring, and, third, to automatically control'the liquid within the fluid springs (the latter being positionedusually at the respective corners of the vehicle'body) I so as to retain said body flexibly at a predetermined normal height irrespective of the load imposed upon said body, or the distribution of the load upon the body,--whereby such automatic control of the fluid within the group of cushion devices tends to maintain the'car body in a normal horizontal position, and thus precludes automatically the body from assuming a tilted or canted position relative to the running gear, it being understood that under all conditions the movable parts of the fluid spring are free to'have a limited relative movement owing to the road conditions so that the fluid spring will act witha certain resiliency so as to absorb road shocks or jars. I I

Broadly stated, the first part of this invention embodies, in connection with a piston, .t'wo moving columns of liquid 1n contact with the respective faces or sides of said piston, the movement of said liquid columns being opposed by suitable cushions which in some cases may be mechanical springs but which' -a're preferably composed ofair'or gas the compressibility of which is governed or controlled 'by the extent of movement of .the liquid columns within the piston cylinders. The movement of each liquid column is opposed to greater or less extent by the compressible cushion and by the frictional resistance due ,to the flow of such liquid through ports connecting the piston cylinder with separate liquid and cushion chambers.

'In a practical embodiment of the invention,

the piston is reciprocable Within a cylinder,

and means are provided for mechanically connecting said piston and the cylinder with the running gearand the body, respectively,

of the-vehicle. Although the piston and the two cushioned liquid columns may be operatively positioned within a single chamber, it is preferred to employ distinct chambers for containing the compressible air or gas cushions and the liquid columns, one .of said chambers being connected by a port with the cylinder above the point normally occupied by the piston within said cylinder, whereas the other chamber is in communication with said cylinder by a port positioned below the normal position occupied by the piston within said cylinder, whereby the liquid columns, in contact with the upper and lower faces respectively of the piston, extend into the chambers, the upper parts of which chambers'contain the compressible 'air or gas.

cushions. c

Provision is made for establishing air or gas at different pressures within the separate chambers, i. 6. air is under considerable pressure in that chamber the liquid column of which is in contact with the upper side of the piston, so as to afl'ord a considerable degree of resiliency or flexibility to the liquid body when the wheels travel over a hum-a "mock or other obstruction in the road, where-- piston '10 the liquid and the air or gas within the v tact of the air or gas with the liquid, thus piston and the cylinder to the gear and the body'may be reversed, e. the piston being connected to the body and the cylinder to the gear.

' Provisionis made to secure two practical conditlons which may, under some clrcumstances, be regarded as of minor importance, to wit:-theemployment of a loose head or mechanical separator between cushion chamber, so as to minimize the conprecluding to a very marked degree the ,emulsification of the air or gas with oil,

should the latter be used as thevliquid col-r umn, and,-further, to control or throttle ,the flow of liquid from beneath the piston, so as to result in a slow movement of the liquid check when the wheels descend into a comparatively deep rut in the road surface, thus precluding a sudden drop of the wheels relative to the body and overcoming a violent recoil of the mechanism, such slow movement of the liquid check operating, also, to

. 'tion is throttled 0r checked in order-to absorb or take care of the sudden, it not violent, movement due to the recoil of the spring, which recoil immediately follows a compression of the spring due to the wheels being lifted by an obstacle in the road. Furthermore, should the wheel .drop into a rut or depression, cling at speed clear an obstac e, sprin porte wheel with great force inaa downward direction, thus resulting in amore or less the car violent shock; but all such objections are overcome in my device owing to the fact tliat the liquid, column in contact with the under face of the piston is throttled, checked, or

' retarded when flowing into the lower chamhowever,

ber, thus overcoming any sudden movement or shock on the car body. At the same time, the lower liquid column is free to follow an upward movement of the piston so as to remain in contact moyement being due to the pressure of the gas or air cushion upon the column and to the suction established in the,piston cylinder by a relative movement between the piston and its cylinder; and, furthermore, the

means whereby two tamed in contact with the respective sur-- recoil of the movable parts of the fluid spring is absorbed when said movable parts return to their normal positions.

Accordingly,- it. is to the first part of my invention embodies any fluid columns are mainor should the ,car 'when trav has'a tendency to force the u'nsup-- therewithgsuch free be understood that,

shift the liquid within the cylinder in one I direction or the other with respect to the piston so as'to return said piston under all load conditions to a predetermined flexible position within "the piston cylinder, .whereby the body of the car, when said car is at rest, is a maintained in a level position and at normal height with respectto its'road contact regardless of the amount or distribution of the load imposed uponthe car body.

It is apparent that a number of my liquid springs are to be used, two, three or more .as may be required, but itis,preferred to emof such liquid springs,'the same being positioned at the respective corners of ploy four the car body. Now, should an excess weight be imposedupon the car, it is obvious that the body and its lead will have a tendency to depressthe cylinders to such an extent with respect to the a disproportionate displacenu'ent of liquid below the-pistons, tending to interfere to a great extent with the proper action of the liquid springs. Again, should thedveight imposed on thehar body be unevenly distributed, one or more liquid springs will'be depressed to a greater extent than the other liquid springor springs, so that itcfollows the car body will be tilted or canted'to'an undesirable position relative to the running gear.-, My liquid-equalizing mechanism associated with each s of the individual fluid springs operates when the vehicle is running for a short period of time so as to impart, practically constantly, a limited relative movement to the parts composing each fluid spring, as a result of which the fluid is shifted so as to automatically correct or pistons that/there results overcome these two serious objections 'due when the car is in motion and a relative movement between the body: and running gear takes place,the liquid-equalizing delvices of the fluid springs are bro ght. into action for the purpose of returning the piston or pistons to a nprlnal predetermined position within the cylinder or cylinders, and as each fluid spring operates under such abnormal conditions to substantially cen- '5 returned to a normal predetermined height.

relative to the running gear in event of an overload, and in the case of unequal distribution of the load the car body will vbe re-.

turned to and flexibly maintained at the desired level position so as to prevent the body fromassuming a canted or tilted'position with respect to therunning gear. 2

Other features and advantages of the invention will appear in the course of the following detailed description.

, In the drawings,

Figure 1 is a vertical central section through a fluid spring embodying this in.- vention. I

Fig. 2 is a side elevation, on a somewhat smaller'scale, illustrating one embodiment of the automatic pump mechanism for shifting the fluid from "a point above said piston to a point below said piston, or vice versa,

scale, illustrating the controlling valve and the liquid connections between a pump and the respective end portions of the fluid containing piston cylinder.

Fig. 4 is a horizontal section through thepump mechanism and a part of the controlling'valve, the plane of the section being indicated by .the dotted line 4-4 of Fig. 2.

Fig. 5 is a detail sectional view, illustrating the automatic throttle for controlling the flow ofthat liquid column which is normally in contact with the under surface of the piston. Adesignates a piston cylinder, and B a piston reciprocable therein. The cylinder and the piston are adapted to be connected respectively with a car body and the running gear thereof, although it is apparent thatthe parts may be reversed by connecting the piston with the car body and thecylinder with the running gear.

and-at its bottom by'a head a, the latter being screwed on the lower end of the cylinder so as to cooperate with a false bottom a in a manner to compress a packing material a between the false bottom and the lower head, thus minimizing leakage. The upper may be discharged by opening the cock at.

05 Furthermore, the plug a may be removed in according to a variation in the load imposed- Cylinder A is closed at its top by a head a order that additional liquid may poured through passage a into the cylinder above piston B therein. 5

C designates a chamber positioned exteriorly to cylinder A andconnected thereto by a port 0 positioned above the piston B. A This chamber C is provided at its lower part with an elbow c which is attached to, or made in one piece with, the cylinder, said elbow 0 forming the port'c which ,establishes communication between the lower part of' chamber (land the upper part of cylinder A. This chamber and the upper part of the cylinder contains a suitable quantity of liquid, such as oil, glycerin, or so the like, adaptedv to form a liquid check above piston B. -The upper part of 1 the chamber C is closed by ahead 03 to which is attached an inflating valve or a pump connection d, whereby air'or gas may be forced 1nto the upper part of chamber C so as to establlsh pressure within the chamber and above the liquid column, which latter partly fills chamber C and the upper part of cylinder A. 1

Operating loosely within the chamber 0 is a piston head D with floats on the-surface of the liquid contained in chamber C and the upper part of cylinder A. Y This piston head is free to rise and fall within the cham her C by a variation in the level of the liquid within said chamber, and, if desired, said piston head may be provided with a central apertured which is adapted to be closed by -a plug D', thus making provision for re-' 160 plenlshmg the supply of liquid within the,

chamber 0. The mam purpose of the piston head D is to mechanically separate the air or'gas from the liquid, whereby emulsification of the liquid is substantially prevented.

. The air or gas which is forced in the upper part of chamber C above the piston head or mechanical separator D establishes an elastic cushion within said chamber and above the moving liquid column, the press 0 ;sure of said'cushion being suflicient to sustain a proportional part ofthe weight of the car body and the weight imposed i thereon.

E is another chamber positioned exteriorly to cylinder A, and having-a liquid connection with the piston chamber through a port'e positioned normally below the low. ermost limit of travel of piston B within said cylinder A. Like the chamber C, the other chamber E is separate from, and is positioned exteriorly to, the piston cylinder A, it being preferred to arrange chamber C on one side of the cylinder A above the piston B v therein, whereas the other chamber E is positioned at the opposite side of cylinder A and preferably parallel thereto. Chamber E is attached to or made integral with cylinder A, and the bottom part c of said chamber E is constructed to form a passage e one end of which terminates in a port 6, whereas'the other end of said passage terminates in a valve seat 0 The chamber C is in communication normally with the piston cylinder through an unobstructed port 0, the area of which is less than the cross sectional area of the chamber, but in the case of the other chamber E the liquid connection between said chamber E and the lower part of the conical to fit the valve seat 6 whereby said.

valve may be adjusted toward or from the valve seat so as to control or throttle the flow of liquid through the passage e The upper part of chamber E is closed by a head.

6 to which is attached an inflating valve or pump connection 6 thus providing means for establishing the pressure of air or' gas within the upper part of chamber E. Within said chamber is a piston head ormechanical separator E adapted to float on the surface of the liquid column which partly fills the chamber E and the lower part of the piston cylinder below said piston B. From the foregoing'description it is apparent that the upper part of the cylinder A abovethe piston B is filled with a column or body of liquid which also fills a chamber C below the piston head D therein, whereas the lower part of cylinder A is filled with liquid below the piston B, which liquid below the piston fills the passage 6 and the chamber E up to the level of the piston head E within said chamber, thus providing two separate bodies or columns of liquid which are normally in contact with theupper and lower surfaces of piston head B. These independent columns of liquid are free to move within thepiston chamber and chambers C E by a relative movement between cylinder A and piston B, but in each instance the movement of the liquid column is opposed by an elastic cushion of air or gas under pressure within the upper part of the chamber within which the liquid column is movable. In this connection it may be stated that the pressure of the air or gas cushion within chamber C is much greater than the corresponding air or gas cushion within the upper part of chamber E. For example, the pressure of the air or gas cushion within chamber C may be eighty pounds to the square inch, more or less, in order that the fluid and the cushion of chamber C will be of a capacity to sustain the weight of the car body and the load, whereas the pressure of the air or gas cushion within the upper part of chamber E may not exceed five or ten pounds to the square inch, such air or gas pressure being employed within chamber E for the purpose of insuring a prompt fiow of the liquid from chamber E into the lower part of cylwhich are inclined reversely to each otherv at 19 and between such inclined faces of the two members is interposed packing B adapted to be compressed by a relative movement of the'members b b. The member I) of the piston is provided with the stem 6 whereas the other. member I) is a part of a sleeve 6, the latter incasing -the stem 6 The stem and the sleeve extend through the lower head a of the cylinder, and said sleeve is provided at its lower exposed part with an internal thread I), and-with a polygonal or square-end b, said threaded part of the sleeve being screwed upon a threaded lower extremity b of the stem 6 whereby the sleeve may be rotated upon the threaded part of the stem to secure a relative movement. of member I) with respect to member 6, thus compressing the packing B so that the piston will have the desired frictional contact with the walls of the cylinder A to prevent leakageof the liquid from one part of the cylinder into another part thereof.

As shown in Fig. 1 the lower extremity of the piston stem b is connected with a link f by a pin f, and the upper end of this link is connected by another pin f to a spring F or other part of the running gear, thus operatively connecting piston B to a member, as. F, of said running gear. .The cylinderv A is connected with the body of the car by means of an arm or bracket G, as shown more particularly in Fig. 2, said cylinder being provided 'exteriorly with an attaching member '9 having pivotal connection with the arm or bracket G by a pin 9 The valve E is a manually operable throttle which is. adapted to be set into any number of predetermined positions for controlling the flow of liquid between the chamber E. and the piston B, but in addition to this throttle it is preferred to employ an automatic throttle, the same being in the form of a valve H, the position of which is indicated in Fig. 1, and which is shown more clearly in Fig. 5. The automatic throttle is a check valve positioned within a recess 71. provided in the wall of the cylinder A at or adjacent to the throttle port a. This automatic throttle valve is hinged or pivotedath', and it is provided with a port if,

the area of which is less than the cross sectional area of passage 6 and port e. The automatic throttle valve is adapted to be shifted by the movement of the liquid column ir o and out of the chamber E, but when the piston B is moved in a downward direction by the recoil of spring F, said piston acts upon the lower column of liquid which in turn presses the automatic throttle valve H to its seat, but at this time the liquid flows through the port 72, of the automatic throttle, whereby the, speed of movement ofthe liquid column under the recoil of the spring'is checkedto a substantial degree, thus eliminating the violent shock which ordinarily would be transmitted to the car body by the recoil ofthe spring acting through the piston upon the lower liquid column. Upon the return of the piston to'a normal position within cylinder A,

the lower liquid column flows from the chamber E into the cylinder below the piston, and at this time the automatic throttle I 'umn of liquid which extends from piston head E within said chamber E to the piston B within cylinder A, said compressible cushion acting upon the lower fluid column to,

insure a prompt return of said liquid body into the cylinder and to maintain said liquid column normally in contact with the under surface of said piston. Piston head E is shown as havlng a port.

6 which is normally-closed by a plug 0",

thus enablingthe operator to remove the plug 6 and pour the liquid throughporte into the chamber E below piston head E,

mounted on the vehicle by connectingcylim der A with bracket G, and piston B with .spring F, although the arrangement may be reversed. The piston B occupies a position within cylinder A substantially midway between ports 0 e, the spacebetween piston B and piston head D being filled with liquid so as to constitute one, body of liquid in contact with the upper surface of the piston.

B, whereas the space between piston head E and piston B is filled with another body of liquid which is in contact with the under surface of the pistonB. Air or gas under pressure is now forced through nipple or pipe 11' into the space of chamber C-above piston head D, andthe air or gas under pressure is also admitted through inflating valve or pipe 61'' into chamber E above plston head E therein. In this connection it is desired to state that the pressure of the air or gas cushion within chamber C is much greater than the pressure of the compressible air or gas chamber within chamber E, I for the reason that the cooperating liquid column above the piston B, and the air or gas cushion within the chamber C which oppose the movement of said upper liquid column,

to form the two liquid columns, and the air or gas to constitute the compressible cushions which cooperate with the respective liquid columns, should be introduced into the fluid spring while the piston B is maintained in a substantially central position, the mechanical spring F of the running :gear being under restraint; but after the liquid bodies and the air or gas shall have been introduced into the fluid spring, the restraint of mechanical spring 'F is taken off so thatthe weight of the car body will be imposed upon the fluid spring. The quantitiesof liquid and the air or gas under pressure maybe propor tioned to sustain the'weight of the" car body and its load. It is to be understood that a number of fluid springs constructed as herein described are employed in connection with the body and the running gear. In some cases it may be suflicient'to employ only two of the fluid springs; in other cases three of the springs may be used, but it is preferred to employ four of said fluid springs, the same being positioned substantially at or adjacent to the respective corners of the car body, whereby the weight of the body and its load will be distributed substantially uniformly upon the four fluid springs. The parts composing the fluid spring are indicated to occupy the positions illustrated in Fig. 1 under a normal load anda substantially equal distribution of the load on the body. I

hen a wheel of the vehicle is lifted by an obstacle in the ,road, the spring F is compressed, thus imparting an upward movement to piston B within cylinder A, which upward movement ofl-the piston imparts an impulse to the upper liquid column so as to move piston head D within chamber C, as a result of which-the upward thrust of thepiston when the spring is first compressed will be cushioned by the compressed air or gas in chamber C so that a-very slight shock' or vibration will be transmitted to the car body, but when the springFlre coils then, ordinarily, the tendency would be to communicate a violent shock or jar tovsaid car body. In my invention, however, thelrecoil ofthe spring F is checked by the liquid column below the piston B. In the ordinary spring suspended body the recoil of the spring following the compression thereof operates to impart a severe jolt to the car body, but by throttling the lower liquid column when the piston moves downward in the cylinder this -shock or jar' is 10, almost entirely eliminated. It'is apparent that when spring F' recoils andpulls on piston B so as to move in a' downward direction within cylinder A, the piston will act upon the lower liquid column, forcing" the valve H to its seat, and causing the liquid to flow through the port of the yalve, the

porte of passagee and into the lower part of chamber E so as to raise the piston head I E against the compressibility of the air or gas cushion within said chamber. Now as the flow of liquid is throttled under the. downward movement o f the piston broughtabout by the recoil of the spring, it follows that the displacement of the lower liquid column will be comparatively slow owing 'to the restricted port of the throttle H, as a result of which the piston cannot be pulled downward suddenly by the recoil of the spring and the speed of movement of the parts is checked to a marked extent so that no violent shock or jar will becommunicated to the car body under the recoil of the spring. When the spring is restored to equilibrium the piston moves upwardly within the cylinder to resume a normal position, and this upward. movement of the cylinder isjfollowed by a quick responsive movement of the lower liquid column due'first to the suction created by the upwardly moving piston,

- 40 and, second, by the pressure of the air or gas within chamber E-acting-through the piston head E to return the column to the lowerpart of cylinderiA below the piston B therein. v p I The throttled movement of the liquid composing the lowercolumn in contact with'the under surface of the piston-performs another important function in the operation of the fluid spring when the wheels drop into arut or depression in the road surface. In

A the case of ordinary spring supported vehicle bodies, the wheel when dropping into l L a rut or depression is thrown orcibly in a downward direction by the aCtIOH' of spring F, thus resulting in a severe jolt on the car body, but a' vehlc'le equipped with my fluidsprings is free from this jolt or jar upon the wheels dropping into a rut or depression for, the reason that the downward movement of 0' the spring is checked andcontrolled by the liquid columnbelow the piston. It is apparent that under these conditions the downward movement of the piston wi]l force the lower liquid column through the restricted port in the automatic throttle valve,

the liquid flowing from the lower part of I cylinder A throughthe valve, passage 6 and upwardly-into chamber E against the resistance offered by the compressible cushion therein, but as this flow of liquid is com parativelyslow'the piston is prevented from having any sudden downward movement, thusminimizin the shock on the car. When the wheels agamtravel on level ground the piston is returned to its normal position and 7 5, 7 this upward movement of the piston is followed by a corresponding upward movement of the liquid column in the cylinder, but "such upward movement of the piston displaces the upper liquid column the move- 'ment of which is' resisted by the compressible air or gas CHShiOIlgWlthlIl the upper part of chamber C, whereby the liquid columns in contact with the respective surfaces of the ';piston absorb any: sudden or undue move-- ment of the wheels or running gear owing to the fact that the compressible air cushion cooperating with the upper liquid column will cushionthe upward movement of the piston, whereas the movement of the lower liquid column 'is throttled'and controlled so as to overcome a sudden downward move- I ment of the piston within the'cylinder. It will be noted that each liquid column is free to move in a direction which compresses the cushion formed by the airor gas in the upper part of. the chamber, and while it is preferred to employ a. compressible cushion formed by a gaseous medium,cit is not desired to limit the invention to such a cushion-, for the reason thata mechanical yielding device may he substituted for the air or gas cushion. 1

The loosepiston head employed upon the top surface of the moving body or column of liquid performs an important function in my structure, for the reason that said-loose piston acts as a mechanical separator between the body of liquid and the air or gas under pressure so as to preclude any direct contact of the air or gas with the liquid, whereby the air or gas will not mix or emul sify with the liquid. It is apparent that each column of liquid is continuous between one face of the cylinder piston and one face of the piston head in the liquid containing chamber, said piston head being free to rise or fall within the chamber; so that the liquid column. will respond instantly to the movement of the piston, and said liquid column will remain no'rmallyincontact with a face of the piston, but this prompt movement of the iston head within 'the compression q ,cham er is-due, mainly, to the fact that the piston head is exposed to the pressure'of the the respective corners of said body.. It is essential that the pistons and the cylindersof the respective fluid springs shall be movable relative to each other in order to perform the functions of absorbing the shock and jar brought'about by the wheels of the vehicle traveling over obstacles and depressions in the road surface, but it is apparent that the imposition of an excessive load upon the car body will depress the cylindersto. an undesirable extent with respect to the pistons and, furthermore, that an unequal distribution of the load upon the body will depress the cylinders of one or more of the fluid springs to a greater extent than .will

- take place in the cylinders of the other fluid springs, as a result of which excessive loading or unequal distribution of the load the body will either be depressed too close to the runninggear or the body will bev caused to assume an inclined or tilted position with respect to said running gear. To overcome these and other objections which are or may vention,

be brought about in the practical use of a car equipped with fluid springs of this inhave provided means whereby the distribution of the liquid in the fluid springs will be equalized so as to compensate for either excessive loading-or an unequal distribution of the load, and to this end each fluid spring is equipped with means usually an automatic. pump, operated in a suitable the form of an annular casing within which 1sopera't1vely arranged a controlling valve J, the latter being provided with a'trans- I verse'liquid way or passage j and with ,a,

. tubular trunnion .j. The valve is propor tion'ed an constructed to'fit tightly "Within the chest but it is free to oscillate or rock therein, the inner face i? of the valve having tight engagement with a corresponding innerface of the valve chest, whereas the e ripheral portion of the valve is provi ed with'on'e or more packings i so as to substantially preclude leakage. The freeend of the valve chest I' is closedby "means of a' head 71 whichfh'asscrew-threaded engage ment withthechest, the packing i being. in-' terp'osed between the head and the edge of the; chest, 'seeFig. 4-. The tubular ,trunnlon j of the controlling valve passes throu h a .suitable opening provided in head 2' o the: valve chest, it being preferred to employ .a

packing 71? around this tubular'trunnion so as to substantially preclude leakage. The passage in thetubular trunnion is in direct communication with the port or way 7' ,of

the controlling valve, and communicating a with this tubular trunnion is a pump cylinder'K, the latter being provided at one end with an elbow is which is attached fixedly by bolts 7c and a packed joint'k? with the protruding end of said'tubular trunnion j.

The pump cylinder thus has direct communication with the port j'of valve J thrdugh the tubular trunnion j thereof, and this pump is attached fixedly to said valve in order that the pump and the valve may have a simultaneous rocking or turning movement, such turning movement being communicated by the pump to the valve as will presently'appear.

the pump cylinder K is positioned alongside of the valve chest and extends in a generally radial direction therefrom, saidpump cylinder being shown in Fig. l as having a guide Zat its outer portion, within which s As dis 0losed more particularlyrin Figs. 2 and 4,

guide is fitted the rod L of a pump piston L, the'latter being'reciprocatory within the cylinder The outer end of the pump piston is provided with ,a cross-pin m, on the end portions of which are loosely mount-f ed friction rolls m, said friction rolls being positioned to travel' withinv slots 12 of verti; cally positioned cambars N, the cross pin m and'guide rolls m" thereon constituting a cross head. The cam bars N are parallel to each other and occupy vertical positions adjacent tothe outer. end of the pump cylinder,

said cam bars being shown as occupymg' normally vertical positions in cooperative relation to the cylinder and the piston rod ofthe liquid circulating pump. Any suitable means may be provided for sup porting 3 the cam bars in fixed relation to the pump,

but it is preferred to employ means ,for aderative relation to the pump piston so as to vary the stroke of said piston as may be desired. In Fig.2 the bar supporting means is shown as extensible arms 0 0' each composed of sections 0 adjustably coupledby a, sleeve o' -v'v'hereby the bar may be lengthened or shortened asdesir'ed. One end of each bar-is attachedfixedlyto cylinder A. by bolts justabl y supportlng said cam bars in coiip- 0 whereas the other end of the bar is fa's-v i tened by abolt 0 to al o" on the eam bar N. Itis'apparent that y lengthemng one 1 bar-O and shortening the other bar 0' the lower-end portion of'the'slotted cam bar may beshifted outwardly and'the upper end portion shifted inwardly with respect to the valve.chest, but a reverse adjustment of the cam bar may be obtained by shortening the lower'ba'r O and lengthening-the upper bar 0'. The cam bar. may also be raised or lowand thus provision is made for 'cha ngingthe position of the cam bars with respect to the ered byadjusti ng the supportingibars- O O.,

whereby the stroke and capacity of the pump may be varied as desired. The slot at in each cam bar is ofi'setat 39 1), said ofl'sets being intermediate the straight end portions of the slot.

It will be seen that the pump mechanism is carried by the cylinde A which is attached to the body, and in order to operate the pump by a relative movement between the body and the running gear .means'are provided for connecting the cross head of the pump piston with the spring F or other part of the running gear. Accordingly, I employ links P the upper ends of which are fitted loosely on the cross-pin m so as to lie between the parallel bars N, said links being connected at their lower ends to a threaded stem p, which is. coupled by a sleeve 19 to a rod 0 the lower end of which 'is connected by abolt 10* to the spring F.

It will be noted that the links P are connected with the spring of the running gear and the pump K is-carried on the cylinder A attached to. the body, as a result of Which a relative movement between the spring and the body will reciprocatethe links P so as to impart movement to the cylinder K, piston rod L and the valve, thus turningthe parts in a manner for the pump and the valve to adjust themselves to the relative movement of the body andrunninggear and for the cross head of the pump piston to travel in the cam slot of the bars N, whereby the pump is se'lf-adjusting and the cam bars act through the cross head to impart reciprocating movement to the pump piston L within cylinder K.

-The valve chest is connected by two independent liquid connections with the upper and lower parts of cylinder A. One set of liquid connections consists of pipes Q Q, whereas the other set of liquid connections consists of pipes R R. The pipes Q Q are attached to the valve chest at diametrically opposite points to each other so that in one position of valve J the adjacent ends of pipes Q Q will communicate with the liquidpassage j of said valve. The pipe Q is connected at its upper part to the top end of cylinder A, whereas the pipe Q" is connected to the lower part of said cylinder, the pipes Q Q communicating with-the cylinder at opposite sides of the limit of travel of piston B within cylinder AL Said pipe Q is provided with a check liquid, @2 6. to prevent the liquid from flowing fromthe lower part of the cylinder A into the upper part of said cylinder. The other set of pipes R R are similarly arranged, that is to say, the adjacent ends of the pipes R R are connected with valve chest" I at diametrically opposite points to each other so that the pipes R R Will permit the flow of liquid through them when the valve J is adjusted for the port 7' thereof to register with the open adjacent ends of the pipes R R. The other end of the pipe'R is connected to the upper part of cylinder A, whereas the other pipe R is connected to the lower part of said cylinder, said pipes R B being provided with check valves 7: r, respectively, which check valves r 1" open in opposite directions to the check valves 9 g in the pipesQ Q, respectively. It isthus apparent that the valves in the pipes Q Q open in a direction which perlimits the flow of liquid from the upper part of cylinder A into the lower part thereof, whereas the check valvesin the pipes R R open in a contrary directipn for the liquid to flow from the lower part of cylinder A into the upper part of the same cylinder. 1 1

In the normal position of the body with respect to the running gear the cylinder K'and piston L are substantially horizontal, as in Fig. 2, for the cross head of the piston to occupy the offset part of the slot in the cam bars, and in the described position of the parts the valve J is adjusted for its port j to be out of register with the two sets of liquid connecting pipes, thus precluding the flow of liquid through the valve ,from either the top or bottom part of cylinder A. The piston B within the cylinder occupies a substantially normally central position between the ports 0 6, although said piston is free to reciprocate within the cylinder under the relative movement between the body and the running gear under normal load condi-' tions and under an equal distribution of the load on the body. I v

The imposition of an excessive load upon the body, however, is followed by a downward movement of cylinder A with respect to piston 13 so that the piston will occupy a position within the cylinder too close to port 0, as a result of which the upper liquid column is elevated within chamberC so as to undesirably compress the air or gas cushion therein and, furthermore, the lower liquid column will be raised toan'undesirable level within the lower part of cylinder A and lowered to a similar undesirable level within chamber E. Under these conditions the slotted bars N attached to cylinder A will be lowered along with-the cylinder A, and thus the crosshead of the piston L will workin the slots of the bars at a point above the. middle of said bars. Now, when the vehicle isrunning and a relative movement takes place between ,th body and the runwithin. the pump cylinder, but when the mechanism is lowered by the load upon the body, the pump cylinder and the valve will be turned so that the ort j in said valve will register with the pipes Q Q. Now, the operation of the pump piston within the cylinder will draw liquid from the upper part of cylinder A and pipe Q forces the liquid through pipe Q and into the lower part of the cylinder, this operation being continued until fresh liquid-is pumpedinto the lower part of cylinder A to restore the piston B to a normal predetermined position within said cylinder A, thus equalizing the distribution of liquid within cylinder A. This action takes place in the cylinder of each fluid spring, the operation being performed when the car runs for a comparatively short distance, and thus all the fluid springs will be operated by the pumps so as to restore the pistons to normally predetermined positions within the cylinders of said springs, as a result of which operation the body will be restored to a predetermined height relative to the running gear.

. It is apparent, furthermore, that upon the removal of the excessive load, a reverse action of the parts will take place, such reverse action being brought about by the relative movement between the body and the running gear so as to shift the pump cylinder and the valve J to a position wherein the port j of the valve will register with the pipes R R, respectively, whereupon the pump will operate to draw liquid from the lower part of cylinder A through pipe R and to'force the liquid through the pipe B into the upper part of the cylinder, thereby efiecting a re-distribution of the liquid in the cylinders of the fluid springs so as to again restore the pistons "to a normal predetermined position between the ports 0 e. Should the load be unequally distributed upon the rear of the body it is apparent that the, cylinders of the rear springs will be depressed to abnormal positions so as to shift the valve J and operate the pumps in a way to re-distribute the liquid in the cylinders of said fluid springs until the pistons within said cylinders are restored to the normal predetermined positions, thereby bringing the car body to a normally horizontal posi tion and at a predetermined height relative to the running gear.

The operation of shifting the liquid in the cylinders of the fluid springs takes place automatically to compensate either for excessive loading of the car body or for an unequal distribution of'the load, said opera: tions being effected by a displacement of the car body from a normal predetermined distance relative to the running gear and to the relative movement between the car body and the running gear when the car is in motion.

Provision is -made for replenishing the supply of liquid in cylinder A either above orbelow the piston by the operation of the pump. To this end a 1i uid reservoir Sis employed and the pipes R .are shown as having branch connections 8 s' with said reservoir. The pipe Q is provided with a valve t which is closed when the valve t in the branch pipe 8 is open. Similarly, the pipe R is provided with a valve to which is closed when the .valve to in the branch pipe 8' is open, whereby the pump will draw liquid from the reservoir S when valves to. are closedand valve tf u are open, thusallowing liquid to be forced into the upper or lower parts of cylinder A by the automatic operation of pump K L. Y

Although I have described that the liquid is shifted in the cylinders by the automatic operation of certain pumps which are actuated by the relative movement between the body and gear, it is apparent that this shifting of the liquid may be performed by man ual operation through suitable valves, and, further, that a liquid circulating pump operated from any source of power may be employed to obtain the efi'ect desired.

While I have described that the pressure of the air or gas cushion in chamber is considerably lower than the corresponding pressure in chamber C. it is evident that the 100 pressures in the two chambers may be equal under certain conditions, or the relative pressures in the two chambers may be proportioned as found necessary or desirable.

In my fluid spring the area of surface exposed to contact of liquid on its top side (termed the compression surface) exceeds the area of surface exposed to liquid on its bottom surface (termed the expansion surface) by reason of the presence of the plston rod connected to said lower piston surface. This variation in the area of the piston surface is important for the reason that in a device of this character it is, the difference in pressure of the cushioned l1'u1d 115 columns which controls the suspen ing power of the spring, and, further, it is desired to maintain elastic pressure in contact with the compression and expansion sides of the piston to insure the requisite movement of the liquid cushions.

top of the cylinder; and, in the case of fast driving, by the amount of swaying and its interference with control of the car, and with driving on steep side grades 1 where there is danger of upsetting. It

is also advantageous, after the spring has become compressed, for the. piston to return as speedily as possible to normal position. When said piston reaches that normal position, ;however, its return movement should be softly resisted, and it is at this stage of the operation that the vretarded flow of one liquid column by the valves H, E are of special utility, said retarded flow or choke ofrthe liquid column taking'efi'ect shortly before the piston reaches its normal-position,

The advantage of a greater or less expansion beyond normal in the'spring is almost entirely dependent upon the amount of speed at'which the vehicle is to be driven. In fast driving, the expansion should be slight and rather slow, for the reason that I if it is rapid the wheels will drop into many road depressions or holes where they would otherwise be carried over by the lnertia of the vehicle, whereas in slow driving the spring should expand and allow-the wheels to seek the bottom of the road depressions or holes as quickly as possible, and With as little tendency to carry the body down as possible. Excessive expansion will have a tendency, also, 'to permit the :danger of the car tipping over, and the danger of swaying when going around corners, for

. to accomplish in this device are the control of (a) the length of the compression stroke of the piston; (b) the resistance opposed to the compression stroke; (0) the length of the expansion stroke; (03) the resistance op-' .posed to the expansionstroke; (e) the speed at which, the BXPHJISIOII stroke can take place; (7) the relative speed at which the recoil from both strokes can take place; and (9) an automatic arrangement whereby the relative pressure below and above thepiston may be altered by the transfer of liquid one way, or the other in order that the normal position of the piston may be the same irrespective of the amount of load sustained.

The pump employed in a'preferred form' of the fluid spring is so arranged that it is actuated by the expansion and compression of the spring and the recoil from expansion and compression, and the valve is automatically moved with the pump, so that when the pump is being actuated by compression and its recoil, hquidismoved from below the piston to above the piston, and

been returned to a normal position.

that the reverse action takes place while the duly compressed, the constant road .vibra-- tions will pump the liquid from below the piston to above the piston until the piston shall have been returned to its normal posi-' tion. Then, if the load is removed and the spring expands to a position beyond normal, the road vibrations willcause the pump to deliver liquid from above the piston to a point below it until the piston shall h iaye 1e pump operates automatically, but it is capable of manual adjustment in such a manner as to vary the normal position of the piston by changing the length of the rod P, whether in conjunction with the main piston rod or not, and a further adjustment is secured by the rods R and 0, thereby controlling the position of the slot. No action of the pump can take place when the valve is closed but it never closes entirely.

When an obstruction is hit by the wheel, the wheel is thrown up and compresses the spring, the spring in turn tends to cause the body to move upward, or rather deflects it from its forward movement in an upward direction. If the speed at which the car is moving isosuflicient, the Wheel will leave the ground, and as the car body is being forced up the spring will have a tendency to greatly expand beyond normal,

and during its expansion will constantly be exerting-an upward pressure upon the car body so that the latter will be forced higher into the air than if the expansion of the spring were limited. This is the chief reason for permitting a small expansion in the spring when driving at a high. rate of speed, which renders a great expansion of the spring undesirable, as when'a depression or hole in the road is crossed and by reason of the great expansion the wheel is forced down to the bottom of the hole, said wheel receivesthe impact from the farther side or shoulder of "the road depression or hole.

Having thus fully described the inven-- tion, what I claim as new, and desire to secure by Letters Patent is:

1. In a fluid spring, the combination with a piston, of means, whereby a plurality of fluid columns are directed into contact with the respective surfaces of said piston, said .12

.cushioned liquid columns are maintained normally in contactwith opposite surfaces of sad piston, each of said liquid columns being independent-of the other.

3. In a fluid spring, the combination with normally in contact with opposite surfaces ofsaid piston, the resistance afforded by the cushion of one fluid column being greater than the resistance of the cushion other-fluid column.

4. In a fluid spring,.the combination with a piston, of a plurality of liquid containing .chambers independent of each other, said chambers operating to directseparate cushioned liquid columnsinto contact with the respective surfaces of said piston and each chamber being provided with means whereby the quantities of liquid and a gaseous cushioning medium may be varied for controlling the thrust of said cushioned liquid column.

5. In a fluid spring, the combination with a cylinder and a piston, of a plurality of chambers separate from the cylinder and connected with said cylinder chamber at points respectively-above and below the position normally occupied by the piston, said separate chambers containing columns of cushioned liquid which are directed into.

contact respectively with the upper and lower surfaces of said piston.

6. In a fluid spring, the combination with a cylinder and a piston, of a plurality of chambers separate from the cylinder and connected therewith by ports the areaof which is less than the cross sectional area of the chambers, said chambers operating to direct cushioned, columns of liquid into contact with the respective faces of said piston.

7. In a fluid spring,'the combination with a cylinder and a piston, of a plurality of chambers connected with said cylinder by ports positioned respectively above and-below the positionnormally occupied by the piston within said cylinder, said chambers operating to directlcushioned liquid into contact with the upper and lower surfaces respectively of said piston, and means for throttling the flowof that body of liquid which is in contact with the lnwer surface sition normally occupied by the piston with-- in the cylinder, said chambers containing separate columns of liquid which are reof the tained under air or gas pressure into contact with the upper and lower surfaces re spectively of the piston.

10. In a fluid spring, the combination with a piston and a-cylinder, of a, plurality of chambers communicating with said cylinder and operating to direct bodies of liquid into contact with the respective faces of said' pis-. ton, ,and means through which said chambers can be inflated for establishing air or' gas pressure therein.

11. In a fluid spring, the combination with a piston and a cylinder, of a plurality of chambers communicating with said cylinder and operating to direct bodies of liquid into contact with the respective faces of said piston, and means through which the chambers can be inflated for establishing air or gas pressure therein to act as cushions for said bodies of liquid, the air or gas pressure in one chamber exceeding the similar pressurein the other chamber.

12. In a fluid spring, the combination with a piston and a cylinder, of a plurality of chambers communicating with said cylinder andv operating to direct bodies of liquid into contact with the respective faces of said piston, and means through which said chambers can be inflated for establishing different pressures of air or gas within said chainber, the pressure within the chamber having the liquidbody in contact with the under surface of the piston being less that the pressure in the other chamber.

13. In a fluid spring, the combination with a piston and a cylinder, of means for directing'a liquid column normally into contact with the upper surface of thepiston, said liquid column bein cushioned and afford ing a yielding medlum to a relative move- I ment between the cylinder and the piston, means for maintaining a separate liquid column into contact with the/under surface of said piston to operate as .a liquid check therefor, and means for throttling the flow of the liquid composing said separate liquid column.

14, In a fluid spring, the combination with a cylinder and a piston, of a chamber for containing a liquid adaptedto check a relative movement between the cylinder and piston, said chamber also containing air or gas to act as a cushion to the liquid check,'and a mechanical separator between the air cushion and the liquid check.

15. In a fluid spring, the combination with acylinder and a piston, of a chamber for containing a liquid adapted to check a relative movement betweenjthe cylinder and piston, said chamber also containing air 'orgas under pressure so as to act as a cushion to the movement of thebodyofliquid, and

a piston head operatingf asa .mechanical separator between the air or gas and the body of liquid.

16. A fluid spring embodying a cylinder and a packed piston operable therein, said piston embodying separate heads and means accessible exteriorly of the cylinder for securing a relative adjustment between said piston heads to expand the packing without removin the piston from the cylinder or taking 0 the cylinder heads.

17. In a fluid spring, the combination with a cylinder and a piston, of means whereby a vmovable liquid column is directed into contact with a surface of thepiston, the movement of which liquid column is opposed by a compressible a r or gas cushion, and a liquid column and the compressible cushion. 18. In a fluid spring, the combination with a cylinder and a piston, of means whereby a movable liquid column is directed into contact with a surface of the piston, the movement of which liquid column is opposed by a compressible air or gas cushion, and a loose piston head positioned intermediate the liquid column and the compressible cushion so as to follow the movement of said liquid column. i

19. In a fluid spring, the combination with a piston and a cylinder, of means for directing a plurality of liquid columns, backed by compressible cushions, into contact with the respective surfaces ofthe piston, and separators positioned to isolate the compressiblecushions from contact with the liquid columns.

20, In a fluid spring, the combination with a cylinder and a piston, of means fordirectin a liquid column, backed by 'a compressi le cushion, into contact with the upper surface of said ing a second li ui column, backed by a compressible cus ion, into contact with the under surface ,of said piston, and means for throttling the flow of liquid composing the second liquid column upon a relative movement-between the piston and cylinder, said throttling means being effective in retarding the second liquid ,column when flowing in a direction to oppose the recoil of a spring and said throttlingv means bein non-efiec- 5o tive when the second liquid co umn is re parts to normal position.

'21. In a vehicle the body of which is displaceable under varying load conditions with respect to a running gear, the combination with a liquid spring embodying a cylinder and a piston, of means for directing sepa-. rate bodies of liquid into contact with the upper surface and the under. surface re spectively of said piston, each body of liquid being cushioned by an air or gas column, and means for shifting the liquid with respect to the piston whereb said piston is retained in a position su stantially centrally with r ct to the cyhnder. i5 22. In a vehicle the body of which is dismechanical separator interposed between the iston, means for directstored within the cylinder by a return of the resisting surfaces respective y of said piston,

placeable under varying load conditions with respect to a running gear, the combination with a liquid spring embodying 2. cylinder and a piston, of means for directing, separate bodies of liquid into contact with the upper surface and the under surface respectively of said piston, each body of liquid being cushioned by an air or gas column, and pumping mechanism for shifting the liquid so as to equalize the distribution ,thereof relatively to the piston according to- Ehel imposition of the load upon the vehicle 23. In a vehicle thebody of which is displaceable under varying load conditions with respect to a running gear, the combination with a ,piston and a cylinder one of which parts is-to be connected with the body and the other part with the running gear, of means for directing'separate liquid bodies into contact with the upper surface and the under surface respectively of said piston, each body of liquid being cushioned by an air or gas column and automaticmeans for shifting the liquid with respect to said piston whereby an excess of liquid on one side of the piston is forced by the action of the liquid shifting means to the opposite side of the piston. v

24. In a vehicle the body of whichis displaceable under varying load conditions with respect to a running gear, the combination withza piston and a cylinder one of which parts 'is to be connected with the body and the other artwith the running gear, of means for directing separate liquid bodies into contact with the upper surface and the under surface respectively of said piston, each body of liquid being cushioned by an air or gas column, and pumpingmechanism o erable by' a relative movement between t e body and the running gear for shifting the liquid from a point above. the piston to a point below the piston, and vice versa, according to the imposition of a load upon the body.

25. In a fluid spring, the combination with a piston and a cylinder, of means for di-' recting cushioned'liquid 'colu'mns into contact with the load-sustainin and expansion- 11 whereby they may be connected respectively 126 with a running gear and body of a vehicle, said cylinder containing liquid at the respective sides of the piston, of means controllable by a relative movement between the body and the running gear for shifting the 130 liquid in the cylinder so as to return the piston to .any predetermined position with said cylinder.

27. In a fluid spring, the combination with a piston and a cylinder having means whereby. they may be connected respectively with a runnnin gear and body of a vehicle, said cylin er containing liquid at the respective sides of the piston, of an auto- ,matic pump having liquid connections with said cylinder at points above and below the normal level of the piston therein, whereby the volume of the liquid may be shifted from above the piston to a point below it, or vice versa, according to the weight and disposition of the load on said body.

28. In a fluid spring, the combination with a piston and a cyllnder having means whereby they may be connected respectively ter to distribute the between said parts, said means bein associated with said pum for driving t elatuid; within the cylinder proportionately to a variation in the I load sustained by one of said relatively movable parts.

32. The combination with a fluid containing cylinderand a piston adapted to be respectively connected, with the relatively movable body and gear of a vehicle, of pump mechanism having fluid connectlons with said cylinder at points above and below the normal travel of the iston within said cylinder, said pump mec anism being operable by the relative movement between the body and gear for distributing the fluid with a runnmggear and body of a vehicle,

said cylinder containing liquid at the respec- ,tive sides of the piston, of a pump operable ating to transfer such fluid from one side of the piston to the opposite side of said piston, and vice versa, said fluid-transliereiiective in distributlng' ring means being the fluid proportionately to a variation of load sustained by one of two relatively movable parts of a vehicle.

30. The combination with a cylinder, and a piston, adapted to be connected respectively to relatively movable parts, of means for retaining fluid under pressure and in contact with the respective surfacesof said piston, a pum separate from said cylinder movable parts.

and c'onnecte therewith, and means for operatin said pump so as to transfer the fluid un er pressure from one side of said iston to the other side thereof whereby the fluid ,within the cylinder is distributed proportionately to a variation of load imposed upon one or the other of said relatively 31. The combination with a cylinder, and a piston, adapted to be connected respectively to parts movable relatively'one to the other, of means for retaining a fluid under pressure and in contact with the respective surfaces of said piston, a pump separate from the cylinder and piston and having fluid connections with said cylinder, and

. means operated by the relative movement within said cylinder load upon the body.

33. The combination with a fluid containing cylinder and a piston adapted to be resnectively connected with the relatively movablebody and gear of a vehicle, of a pump mechanism for distributing the fluid within said cylinder proportionately to the load imposed upon the body,-said pum proportionately to the mechanism having fluid connections wit said cylinder at points above and below the normal travel of the piston within said cylinder, and means 'for controlling the direc-' tion of flow of the fluid.

34. The combination with a fluid containing cylinder and a piston adapted to be respectivelyv connected with the relatively movable body and gear of a vehicle, of a pump mechanismior distributing the fluid within said cylinder proportionately tothe load imposed upon the body, and an automatic valve the piston of which is controllable by the relative distance between the body and gear, said valve operating to control the direction of flow of the fluid through the pump mechanism and with respect to the chambers within said cylinder.

35. The combination with a cylinder and a piston one adapted to be connected with a body and the other connected with a running gear of a vehicle,a pum for distributing a fluid within said cylin er proportionately to a variation in the load imposed upon the vehicle body, and valve mecha-.

nism for controlling the flow of fluid to said pump, said valve mechanism bein able by a change in the relative intervening between the body and the gear.

36. The combination with a cylinder and opera piston whereof one part is' adapted to be connected witha body and the other part is adapted to be attached to a running gear of a vehicle,a ump operable for distributing a fluid wit in the cylinder proportionately to a variation in the load imposed on the vehicle body, and a valve mechanism for controllin the ,flow of fluid to said cylinder, said va ve mechanism and said pump being shiftable to difierent operating posiistance v directing cushioned liquid columns into con-' tact with the compression and expansion" pumpiflsaid valve mechanism bein tions by a variation in the position of the vehicle body relative to said vehicle gear. 37. In a fluid spring, the combination with a piston and a cylinder, of means for directing cushioned liquid columns into normal contact with the compression and expansion surfaces respectively of said piston, and means. for controlling the flow in two directions of that liquid column which is normally directed into contact with the expansion surface of the piston whereby on the expansion stroke of the piston due to the recoil of a vehicle spring, a relatively slow movement is obtained, and upon the compression stroke of said piston the liquid column offers a decreased resistance to said stroke. v

38. In a fluid spring, the combination with a piston and a cylinder, of'means for directing cushioned liquid columns into normal contact with the compression and expansion surfaces respectively of said piston, and a throttle valve positioned for controlling the flow of that liquid column which is in contact with the expansion surface of the piston, said throttle valve operating to retard the movement in one direction of that liquid column in contact with the expansion surface of the piston, and said throttle valve being opened automatically upon the movement in the other direction of said liquid column, so as to permit sub stantially free movement in said opposite direction unrestrained by said valve.

39. In a fluid spring, the combination with a piston and a cylinder, of means for surfaces respectively of said piston, a throttle valve in the line of movement of that liquid column in contact with the expansion surface of the piston, said valve being provided with a normally open port, and

a'manually opera'ble'valve for controlling I the flow of that liquid column which is in contact with the expansion surface of the piston. I

40. The combination with a cylinder, and a piston, adapted to be respectively connected with a body and a gear of a vehicle, a pump connected with the cylinder and operating to d1 St11b11t6 a fluid within the cylinder proportlonately to a variation in the load imposed upon the body, and valve mechanism for controlling the flow of fluid to said controlla e by a change in the relative distance between said body and the gear.and said valve mechanism being effective in determining the direction of flow of the fluid with respect to the cylinder.

41. The combination with a cylinder,- and a piston, adapted to be respectively connected with a body and a gear of a vehicle, a'pump connected with the cylinder and operating to distribute a fluid within the able to variable operative positions by a variation in the relative positions of said body and the vehicle gear.

42. The combination With a fluid con taining cylinder and a piston adapted to be respectively connected with the relatively movable body and gear of a vehicle, of a rotative valve for controlling the direction of flow of the fluid with respect tothe cylinder, means connected with a part of the ve-' hicle for imparting rotative movement to the valve, and a pump having fluid connections with the cylinder, said pump being carried on one vehicle-part and mechanically connected with another vehicle part so as to be operated by a relative movement between said vehicle parts.

43. The combination with a fluid containing cylinder and a piston adapted to be respectively connected with the relatively movable body and gear of a vehicle, of a pump for distributing the fluid in the cylinder, a valve for controlling the direction of flow of the fluid,. means for shifting the valve, and means for operating said pump.

44:. The combination with a fluid containing cylinder and a piston adapted to be respectively connected with the relatively movable body and gear of a vehicle, of a pump having fluid connections with the respective end portions of said cylinder, means for operating said pump, and a valve cooperat ing with the pump and the cylinder for controlling the direction of flow of the fluid through said pump.

45. The combination with a fluid cortaining cylinder and a piston adapted to herespectivelv connected with the relatively'movable bOdv and gear of a vehicle, of a valve chest having two sets of fluid connections with said cylinder at points above and below the travel of the piston therein, a valve for controlling the direction of, flow of the fluid through one set of said fluid connections to the exclusion of the other set, and vice versa, means for shifting the valve, a pump, andmeans for operating said pump.

46. The combination with a fluid containing cylinder and a piston adapted to be respectively connected with the relatively movable body and gear of a vehicle, of, a valve chest having two sets of fluid connections with said cylinder at points above and below the travel of the piston therein, a valve III III

rotatable in the valve chest and operable to shut ofl' the flow of fluid and to control the direction of flow through one set-of fluid connections, a pump cooperating with said valve, and means for operating said pump.

47. The combination with -a fluid containing cylinder and a piston adapted to here sgectlvely connected with the relatively mova pf fluid, relative-to the cylinder, a recipro-- eating pistonpump cooperating with said valve, and means operated by a relative movement between-the bod and. gear for operating the ump. p 48. The com ination witha fluid contain ing cylinder and a piston adapted to-be res ectively'connected with the relatively mov- ,20' a le body and gear of a vehicle, of a valve chest connected to the cylinder, a valve within said chest, a pump the cylinder of which is connected with the valve, a cam 'cooperating with the piston of said pump, and

means for imparting movement to S d pump piston;

49. The combination with a fluid contain ing cylinder and a piston adapted to be res ectlvely connected with the relatively mova a le'body and gear of a vehicle, of a valve chest on said cylinder; mutiple fluid connections between said valve chest and the respective portions of the cylinder, 'said fluid connections having .check valves for 35. controlling the direction of flow of the fluid.

a reversing and shut ofi valve operable with in said valve chest, a pump eoiiperating with the valve, and means for operating said P 40 50. The comblnation w1th a flmd contamle body and gear of acvehicle, of a valve- .10/ chest connected withsaid cylinder, a valve within said cliest'for controlling the flow for distributing the fluid therein proportlonatel to the load upon the body, and means 9r replenishing the liquid supply o said pump- 51.. The combination with a fluid contain- 1ng cyhnder and a piston adapted 'to be resyectively connected with the relatively mova le body and gear of avehicle, of pumping mechanism cooperating with the cyllnder for distributing the fluid therein proportionately to the load upon the body, a reservoir, and means coiiperatin with the pump for replenishing the liqui y feeding the same from the reservoir to the cylinder. q

52. In,a fluid spring, the combination with cylinder and a piston, of a plurality of chambers containing cushioned liquid columns one of which is directed normally into contact with the load sustaining surface of the piston and the-other into contact with the recoil retarding surface ofthe same piston. v

' 53. In avehicle, the combination with a running gear, and a body displaceable under varying load conditions with respect to said running gear, of liquid controlled spr ng mechanism for returning the bodyto, and retaining it .yieldably at, a normal predetermined distance with respect to the attachment to the runninggear, .said liquid controlled spring inechanism embodying a cylinder, alpiston, means for retaimng separate, cushion bodies of liquid m contact with the up er surface and the lower surface respectlvely of said iston, and pump mechanism for shifting t e liquid w1th respect to the piston.

In testimony whereof I have signed my name to this specification in the presence .of two subscribm witnesses.

' CHABL S SNOW KELLOGG. Witnesses:

M. G. Boometmz, H. I. Bmmmm.

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