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Publication numberUS3603578 A
Publication typeGrant
Publication dateSep 7, 1971
Filing dateJun 12, 1969
Priority dateJun 12, 1969
Publication numberUS 3603578 A, US 3603578A, US-A-3603578, US3603578 A, US3603578A
InventorsHerrera Jose Pardo
Original AssigneeHerrera Jose Pardo
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hydraulic balancing mechanism
US 3603578 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

l I l l 3 611 3 7 267/128 FllMS/UO 267/113 128,141,71

Avenidn de las Torres 92, Znom 9,

References Cited shdable hollow rod carrylng the bushing, there bemg commu- UNITED STATES PATENTS nication between the chambers through said bore, the rod and a lateral opening in the latter, and valve means for said bore of the bushing operably mounted in the hollow of the rod.

3,008,746 Senger.........l................ 267/128 PATEHTTU 85? 71971 9 I w J 1;,

INVENTOR, time Eva; Her/82 w,


HYDRAULIC BALANCING MECHANISM The instances for use of a hydraulic balancing mechanism or system are numerous in many cases in which elements of a certain weight or volume must be oscillated or turned by hand, but vary their operation according to the differences in the size or weight of the element, making it necessary to dismantle at least part of the mechanism of the balancing means to adjust same.

Widespread employment of the mechanism or system is in the holding and storage of disappearing beds, during the day in dwellings. At present this is generally attained by using bulky and much maneuverable transformable furniture, without completely fulfilling the purpose of real beds.

Through the instant hydraulic mechanism it is possible to tilt or rock a complete'bed around an axis located within a wall cavity or equivalent, and swing the bed completelyinto the cavity or similarly mount the bed between parallel partitions in a frame or article of furniture, so that during daytime the space usually occupied by the bed is completely'free for other uses. a

The foregoing example does not limit the use of the inven' tion, since other examples are the balancingof large gates in manufacturing plants, upwardly swinging doors at garage entrances, rigid shutters to protect the plate glass of show windows in case of violence as well as many other no less interesting cases.

In the present invention, hydraulic means have been employed so as to make the same manually adjustable without the necessity of any dismantling of parts, even during operation. The invention provides a preferably metallic cylinder in which is contained a relatively strong helicoidal spring, a piston sliding hermetically in said cylinder defining an upper and lower chamber therein, the upper extremity of said strong spring engaging the lower face of said piston, a hermetically sealed cover for the upper extremity of the cylinder, a straight tubular rod which extends hermetically tight through and slides in said cover into the upper chamber of the cylinder and slidably into the upper portion of said piston and with the bore of the tubular rod enabling communication with the lower chamber of the cylinder. To the interior of the lower extremity of said tubular rod, the upper portion of a tubular bushing is attached as by screw threading. The bushing has a bore throughout its length and the upper edge of the bore is a valve seat which is approximately level with the upper end of the piston. Said tubular rod above the location of said valve seat has a small lateral opening 12 which communicates with the upper chamber of the cylinder. The tubular inside or bore of the rod contains a longitudinally movable valve pin whose lower extremity may be conical and adapted to seat hermetically at the adjacent circular edge of the mentioned bushing, and the upper extremity of which is a stopper.

Said stopper is an enlargement of, rigid, or integral with the pin which seal hermetically the upper extremity of the bore of the rod. Such stopper is screwed to the bore wall of the rod and at its outside extremity the rod at the stopper has a manual means operable to adjust said screwing in such a manner that the conical extremity of the rod may close by seating at the upper end of the bore of said bushing.

In the accompanying drawing of one example of the invention:

FIG. 11 is a diagrammatic elevational view of a head portion of a bed concealed in a wall recessed, for example, and its association with the balancing hydraulic means of this invention;

FIG. 2 is a diagrammatic elevational view of the same parts as FIG. 11 in position after the bed has been oscillated to its horizontal or open position for use, particularly emphasizing the raising of the arm joining it to said balancing hydraulic means; and

FIG. 3 is an enlarged sectional view taken substantially along the longitudinal axis of the hydraulic cylinder of the balancing means.

In said drawings, FIGS. 1 and 2 illustrate how, in the case of a tilting bed A pivoted at a and concealed in a vertical position in a recess B ofa wall or equivalently in an article of furniture, for example, the balancing means at cylinder 1 being con nected by means of arm C hinged at 1b to the bed. In FIG. 2 said arm C has been raised, which raising also raises cylinder 1 relatively to its tubular rod 2 hinged at its upper extremity to a fixed projection 28 on the rear wall or equivalent place within the recess B.

In FIG. 3, said arm C is rigid, or integral with said cylinder 1, the parts being primarily metallic and the cylinder being closed at its base.

The rod 2 is a tubular straight metallic part and its lower extremity, usually interiorally enlarged at 2a, slidably enters into the upper area of the axial opening or bore 3a of a piston 3. A bushing 4 is carried by tubular rod Z'being screwed at 20 into said enlarged portion2a of the'rod 2. Moreover, said piston slides relatively to the unitary tubular rod 2 and'bushing 4 and the bushing 4 carries midway of its ends, a sliding hermetic seal joint 14 which creates between the rod 2, the piston 3 and the bushing 4 a hermetic and united unit.

THe cylindrical outside wall of piston 3" has the necessary circular seal or joint 15 to obtain the tightness which must exist around the piston to define and maintain the independence of the two chambers D and E within the cylinder, said joint 15 being toric at the same time to permit gentle sliding. Said chamber D preferably contains a suitable liquid.

The cylinder at its upper extremity has a removable cover, or head 5 which has a hermetic seal therewith by means of a toric joint 16 preferably large, to facilitate its insertion. Through an opening in said head 5 said rod 2 is slidable and since the latter sliding is frequent, maximum tightness must be obtained, as by means of a removable flat or skelper bushing 17, a removable double retainer 18 and a removable elastic ring 19, all composing a unitary removable cylinder, piston and rod of the hydraulic means.

A strong helicoidal, or equivalent, spring 7 is contained in the lower chamber D of the cylinder ll, resting on the bottom thereof and the upper extremity is in contact with a large disc 6 through which bushing 4i slidably passes, bushing 4 is fastened in place by a nut 11 screwed to it. A thin washer, or ring 20 is disposed intermediate the piston 3 and disc 6.

When the apparatus such as the bed A is lowered from the position of FIG. 1 to that of FIG. 2, the element A of the bed moves counterclockwise as shown by the arrow X in FIG. I of the drawing; cylinder 1 is raised by said arm'C resulting in the reduction in the size of chamber D, the fluid contained in the latter partly displaces or raises through the bore 4a of the bushing 4 from chamber D into the bore of rod 2 at 2a and thence through a lateral hole 12 of rod 2 above the upper face of the piston 3 and into the chamber lE while at the same time tensioning of the helicoidal spring 7 increases since it is compressed through the raising of cylinder I. When the bed A is raised to its stored-away position of FIG. 2 of the drawing, the bed A will move clockwise as indicated by the arrow Z of FIG. 2 of the drawing.

Under the conditions described, the operation of this hydraulic means always has the same resistance under similar circumstances and conditions as occurs in known shock absorber arrangements. In others, it is possible to vary the sec tion of passage of the fluid by placing before same an eccentn'c washer whose position is varied by disassembling the piston.

According to the invention, the variation of the passage for the fluid is obtained by placing inside of the tubular rod 2 an axially movable valve bar, or pin 10 whose diameter is slightly larger than that of the bore 4a of the bushing 4. Said valve pin at its lower extremity is preferably conical to coact wit the mouth, or valve seat 4b of said bushing 45. At its upper extremity, the valve pin is welded to a cylindrical plug 8 housed hermetically in an internal enlargement 2d of the rod 2. Around this plug, or enlargement 8 are toric hermetic seals 21 which permit both axial and longitudinal movement of the pin l0.

Said plug 8, in its upper portion, has a somewhat greater diameter so that it can better be threaded at 2e in the internal threads with which rod 2 is equipped. Above said threaded portion 2e, plug 8 has a head 2f accessible so that it may be adjustably turned along with its connected pin in one direction or the other for the purpose of seating the pin 10 at 4!; or spacing it therefrom. ln the present example, said head 2f has several radial holes 8a for tool engagement to exert a tangential force to the right or to the left.

If the cone of the valve pin 10 engages seat 4b it will close the passage to the fluid originating from chamber D of the cylinder when said chamber is being reduced in size and therefore will prevent this relative movement between the cylinder and its rod, and the hinging of the elements of the apparatus, or mechanism being operated will be immobilized. The greater separation, or space between the above-mentioned seat 41) and the conical extremity of pin 10 the more fluid shall be able to pass during a unit of time and the movement of the mechanism shall be obtained more easily. Finally, with a sufficient separation of said conical extremity above the lateral passage 12 of rod 2, this passage is completely free, as if the regulating valve pin 10 did not exist.

The upper extremity of tubular rod 2 is detachably and turnably mounted at H as to the arm 28 fastened to a wall within recess B, the structure being detailed at the top of FIG. 3. Such tubular rod extends turnably and detachably into a coupling 29 in which position it is held by split spring means 22 engaged in grooves 22a of the tubular rod. Near the top, the coupling has two holes in which a cylindrical pivot means 24 is accommodated, being retained in place as by pins 25. The coupling 29 is open or has clearance at 26 to permit application and operation of a tool to engage one or both of the holes 8a to adjust, or regulate the height of valve pin 10 relative to seat 4b. The above-mentioned pivot member 24 is used to hinge the hydraulic means to any adequate support, such as a bifurcation of arm 28.

Piston 3 also has one or more passages 13 therethrough, parallel with the axis of tubular rod 2, the outlet of which is at the lower face of the piston and covered by one or several flexible discs, or membranes, 9 which are pressed against said face by a circular spring 27 supported on a shoulder washer, a of disc 6.

After bringing the apparatus, or mechanism which is being operated, to its final position, there is a recovery of the fluid between the two chambers D and E. If the pressure of said fluid is sufficiently strong in the upper chamber to overcome the normal tension of the spring 27 upon its bushing by membrane 9, said spring 27 pressing against the shoulder 27a of disc 6 and thus being filtered with more or less intensity toward said lower chamber furthering the tension of the compressed spring 7.


1. Apparatus of the class described comprising a cylinder, a piston therein intermediate the ends thereof providing a first chamber at one side thereof and a second chamber at the other side thereof, a spring in said first chamber compressible against said piston to tension it through relative movement of the cylinder and piston in one direction, a tubular rod axially slidable into one end of said cylinder, said second chamber and said piston, the bore of said tubular rod above the piston communicating with the second chamber, a single valve means comprising a bushing and a valve pin, carried by said tubular rod, said bushing extending through the piston and having a passage therethrough communicating with the second chamber by means of the bore of said tubular rod and having a valve seat, said valve pin being disposed within said tubular rod and being rotatively and longitudinally movable relatively to said rod and to said valve seat to control the passage of fluid through the bushing from one chamber to the other chamber.

2. Apparatus according to claim 1 wherein said valve pin is screw threaded to said tubular rod for adjustment to vary its spacing with respect to its seat.

3. Apparatus according to claim 1 wherein said bushing 18 screwed to said tubular rod and said valve pin is adjustably screw threaded to said tubular rod.

4. Apparatus according to claim 1 including a coupling to which said tubular rod is fastened, having clearance at one location, means on said valve pin extending into said clearance operable to adjust the position of the valve pin relatively to the seat, and fixed mounting means for said coupling.

5. Apparatus according to claim 1 wherein said piston has a passage therethrough, a flexible disc means covering said passage, a disc member on said bushing below said piston, a nut on said piston below said disc member, and an expansive spring mounted on sad disc member varying against said flexible disc.

6. Apparatus according to claim 1 wherein the bore of said rod is enlarged at its upper portion, an enlargement on said rod disposed in the first-mentioned enlargement, said secondmentioned enlargement being screw threaded to the hollow rod, means to movably couple said rod to a support, and said rod being accessible at its upper end portion for adjustment of the pin valve at screw threads to vary the position of the valve pin relative to its seat.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3008746 *May 27, 1959Nov 14, 1961Senger Albert CPivotally mounted hydraulic bumper assembly for vehicles
US3236515 *Oct 15, 1962Feb 22, 1966Sandex IncHydraulic position lock
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4883387 *Jun 29, 1988Nov 28, 1989Conoco, Inc.Apparatus for tensioning a riser
DE102008053092A1 *Oct 24, 2008Apr 29, 2010Shimano Inc., SakaiBicycle suspension system, has adjusting body including surface area for contacting channel surface during closed position of damping unit, where surface area has form curved relative to main fluid flow direction
DE102008053092B4 *Oct 24, 2008Jul 10, 2014Shimano Inc.Fahrradfederungssystem
U.S. Classification267/128
International ClassificationF16F9/56, A47C17/40, A47C17/00
Cooperative ClassificationF16F9/56, A47C17/40
European ClassificationA47C17/40, F16F9/56