Snap-in rotatable cylinder control

A control for a fluid cylinder includes a cylindrical housing made of a polymeric material which pivotally receives a control arm having a cable release receiving member at one end and which can be snap-fitted within an open end of a pneumatic cylinder to lockably engage a valve spacer manufactured as part of the cylinder. With such a system, the control can be installed in the cylinder and rotated to position the cable release in any orientation within a 360° adjustment range to allow proper alignment of the cable release.

BACKGROUND OF THE INVENTION

The present invention relates to a control for use in connection with an adjustable pneumatic cylinder.

Pneumatic adjustment cylinders are frequently employed for adjusting a movable member with respect to a fixed base. Frequently, such cylinders are employed in connection with adjustable height office chairs, tables, and the like. In the past, controls for actuating the valves for such adjustable cylinders have been manufactured such that they position the cable control in a direction for mounting to the chair or table in a particular orientation, such as the left side, right side, center or other location. In such installations, it is necessary to properly align the pneumatic cylinder during assembly in the chair or table such that the cable control is correctly positioned for coupling to an actuator, lever, or button. Slight misalignment can cause excessive wear during use or inoperability of the control. There exists a need, therefore, for a pneumatic cylinder valve control which facilitates installation and which allows adjustability of the exit position of the control cable therefor and one which can be used with existing cylinder designs.

SUMMARY OF THE INVENTION

The control of the present invention satisfies this need by providing a housing made of a polymeric material which pivotally receives a control arm having a cable control receiving member at one end and which can be snap-fitted within an open end of a fluid cylinder after its manufacture. With such a system, the control can be installed in the fluid cylinder, such as a pneumatic cylinder, and rotated to position a cable control in any orientation within a 360° adjustment range to allow proper alignment of the cable control to the desired location. Such a universal snap-in control, therefore, can be used for left, right, middle, or any other location in, for example, a chair, thereby providing the manufacturer the options of locating the actuator, lever, or button at any desired position. The control system components can be molded of a suitable polymeric material and easily assembled, and subsequently snap-fitted within an existing pneumatic cylinder, thereby reducing the cost of a control system as well as providing desired flexibility for installation.

These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially toFIG. 1, there is shown a pneumatic cylinder10incorporating the control system of the present invention. Cylinder10includes an outer cylindrical housing12in which there is positioned a piston14coupled to a piston rod16, which extends downwardly to a thrust bearing18coupled to a base20, such as a chair base to allow rotation of the cylinder10with respect to the base20. A cover sleeve22extends over the piston rod16and slidably engages the outer cylindrical surface of cylinder10to allow, upon actuation of the control valve24by the control assembly30of the present invention, a support member60, such as the chair bottom to be vertically adjustable with respect to base20. The upper end of cylinder10is tapered at13and is received in a tapered socket15of bracket17coupled to the bottom62of the chair or table60. Opening19in bracket17provides access to the upper end of cylinder10and allows installation of the cable control30, described below, and attachment of a release or control cable65thereto, which extends to a push-button (or other type) control70which can be positioned at any desired location within a chair or table due to the unique nature of the control30.

As best seen inFIGS. 1 and 7, valve24has a control element or rod25extending upwardly and which is selectively engaged by control30of the present invention. The cylinder10includes a valve spacer21which is crimped to the top opening of housing12, as best seen inFIG. 6. Valve spacer21includes an annular undercut surface23(FIG. 2) which secures the snap-fit control30therein, as seen inFIGS. 1 and 7, once control30is inserted into the top opening26of spacer21, as illustrated inFIG. 6.

Control30includes an actuating button32which includes a central axially extending blind aperture34for receiving control rod25of valve24. As best seen inFIG. 3, button32includes a camming upper surface36which is elliptically curved from the outer edge33to the crown35to engage a rounded camming surface45on control arm40of control30. The control arm40is pivotally received within housing50, as described below.

Housing50is generally cylindrical and includes vertical slots52along its lower cylindrical side wall to allow flexibility for the bottom outwardly projecting arcuate flanges54, which engage the annular surface23of valve spacer21, as best seen inFIGS. 1,7, and8, when assembled. The four 90° spaced slots52thereby define four resilient legs53of housing50(FIGS. 4 and 5) to allow them to deflect and extend within the cylindrical opening26of valve spacer21during insertion of the assembly, as illustrated by arrow A inFIG. 6. Housing50includes an open top56through which control arm40extends once assembled, as seen inFIG. 6. A cylindrical socket57(FIGS. 4 and 5) is formed in a mounting boss58on the inner cylindrical side59of the housing for receiving a pivot axle47on control arm40. Control arm40is inserted upwardly into the lower open end55of housing50, as illustrated by arrow B inFIGS. 3 and 4, until the pivot axle47, extending from opposite sides of control arm40, engages and snap-fits within socket57.

The control cam45of control arm40is offset from pivot axle47such that pivotal movement of the upper end44of arm40will provide a mechanical advantage due to the spacing between pivot axle47and cam45and the greater distance between pivot axle47and end44to actuate control button32against the pneumatic pressure of valve control element or rod25. End44of control arm40includes a radially and axially extending slot46for receiving a standard cylindrical end of a cable release65which can be extended within the cylindrical opening48of slot46and rotated until the cable is captively held to end44of control arm40.

The actuating button32, housing50, and control arm40can all be individually integrally molded of a suitable polymeric material, such as acetal, which provides the necessary strength and rigidity and yet flexibility for the snap-insertion of housing50into valve spacer21, as illustrated inFIG. 6, to an installed position, as shown inFIG. 7, in which the camming surface45of control arm40is shown in an opening position for valve24. Thus, arm40is moved to the right, as shown by arrow C (FIG. 7) to depress button32actuating valve22for lowering the element60with respect to base20.

Control30can, thus, be assembled to pneumatic cylinder10by inserting control button32downwardly through open end26of the spacer21, positioning control arm40into housing50and subsequently snap-fitting the housing downwardly into opening26deflecting legs53until flanges54engaged the annular surface23of valve spacer21, which snap-fits control30into open end26of pneumatic cylinder10. The polymeric interface between the typically aluminum valve spacer21and the housing50allows the housing and control arm pivotally mounted thereto to rotate, as seen by arrow D inFIG. 8, through 360°, allowing positioning of release cable65at any desired location with respect to the element being controlled by cylinder10. Thus, the control30will permit left side, right side, front, rear, or any incremental position therebetween for the positioning of push-button or other type of actuating control70on, for example, a chair base or arm or to the undersurface of a table at any desired location.

Typically, during manufacture of a chair, the cable release65and control70will be prepositioned and the coupling of the end of cable65to control30can be easily accommodated as the control cylinder10is secured to the chair base and undersurface of the chair to accommodate whatever position cable65is located. Thus, the system of the present invention provides a great degree of flexibility for the manufacturer and provides an inexpensive, durable, and flexible control for activating an adjustable fluid cylinder.

It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.