US2042443A - Adjustable supporting pillar or the like - Google Patents

Description

May 26, 1936. I w. BUCKSTONE 2,042,443

ADJUSTABLE SUPPORTING PILLAR OR THE LIKE Filed March 15, 1956 2 Sheets-Sheet 1 HTTOB/VEXI May 26, 1936. w. BUCKSTONE ADJUSTABLE SUPPORTING PILLAR OR THE LIKE Filed March 13, 1936 2 Sheets-Sheet 2 WA 7 4 x/ I w m m km m mzerBucbZi Patented May 26, 1936 umreo STATES PATENT OFFICE ADJUSTABLE SUPPORTING PILLAR OR THE LIKE Walter Buckstone, London, England, assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New York Application March 13, 1936, Serial No. 68,706 In Great Britain February 4, 1935 9 Claims.

lower part so as to adjust the height of the support.

When a device of this type is employed to support instruments which are liable to be damaged or thrown out of adjustment by a sudden jar or rapid vertical movement, great care has to be exercised during vertical adjustment of the support since a sudden downward movement may cause considerable damage to the instrument and, in the case of a photographic camera, would certainly throw this out of adjustment. One object of the present invention is to overcome this difficulty.

To this end in an adjustable supporting pillar according to the present invention the lower part of the pillar constitutes a hydraulic cylinder in which can reciprocate a piston carried by the upper part of the pillar and furnished with a valve which is held in its closed position by the liquid pressure beneath the piston, preferably with the aid of a low tension spring, a manuallyoperated release device for the valve being provided on the upper part of the pillar.

Conveniently the valve is held firmly closed by the upward action thereon of the liquid pressure within the cylinder due to the weight of the upper pillar part which may be hollow, the valve, which thus controls the communication between the cylinder beneath the piston and the interior of the upper part of the pillar, being moved downwards when the upper pillar part is to be lowered.

The valve may be so dimensioned that the weight of the upper pillar part must be manually supported before the valve can be opened to permit liquid to be displaced from the cylinder as the upper part of the pillar is lowered. Thus, when the valve is in its closed position, the weight on the upper pillar part is firmly carried by the liquid beneath the piston and, when it is desired to lower the pillar, the weight of the upper part and its, load must be manually supported before the valve canbe opened to permit liquid to be displaced from the cylinder as the upper part of the pillar is lowered.

The invention may be applied to adjustable supports for various purposes but one construc tion according to the invention, together with a modification thereof, are illustrated by way of example as applied to a tripod for supporting photographic cameras, say, for-medical purposes when ready adjustment ofthe camera as a whole is. desirable for making exposures from above beds, operating tables and the like. In the drawings Figure 1 illustrates the tripod base and pillar in perspective,

Figure 2 is a vertical section on an enlarged scale of the upper pillar part and a portion of the lower pillar part,

Figure 3 is a view similar to that of Figure 2 of a modified construction, and

Figure 4 illustrates a modified construction.

In the construction shown in Figures 1 and 2 the support comprises a lower pillar part A furnished with a triangular base plate or block B having pivotally connected thereto legs B which 15 are in turn connected by links B to a collar B slidable along the lower pillar part A.

The lower pillar part A is hollow as shown in Figure 2 and contains liquid such, for example, as oil, the upper end of the part A being open to 20 receive a hollow upper pillar part C. The lower part A thus constitutes a hydraulic cylinder within which the upper part C can reciprocate as a piston for the purpose hereinafter described. The upper part C comprises a hollow tube furnished at its lower end with a plug-like member C externally threaded to cooperate with an internal thread in the corresponding end of the tube. The plug 0 has an integral extension C which is externally threaded so as to cooperate with an 30 internally threaded spacer C and two lock nuts C After the plug C has been screwed into the lower end of the upper part C a cup leather C is inserted over the extension C whereupon the spacer C is screwed into position. Instead of 35 the spacer C being in threaded engagement with the e'xtension C this spacer may cooperate with the extension in the manner of a washer.

A second cup leather C which is directed oppositely to the cup leather C is then placed over 40 the extension C whereupon a castellated spring metal washer C is placed in position and the parts locked in place by the nuts 0*.

The upper end of the tube C is closed by a plug D having an external thread for cooperation with an internal thread at the upper end of the tube, the plug D having an'a'nnular groove D which, when the plug is in position, communicates with an aperture or breather port D in the upper end of the tube C. The plug D has an integral cross member D furnished with lugs D and D upon which lamp and camera brackets F and G are adjustably supported.

The plug 0 has a bore E leading to a valve seating E .formed at the lower .end of the ex tension C and adapted'to cooperate with a valve E formed at the lower end of a valve release device comprising a spindle E? which, for ease of assembly, comprises two parts abutting at M, a spring 7 M normally holding up the lower part and maintaining the valve E on its seat. The lower part of the spindle passes through a bore E in the plug C so that there is sufiicient clearance for the flow of liquid. Theupper part of the spindle E f passes freely through the plugrD and is furnished with a button E and a conical enlargement E 7 which is normally held on a seating in the'plug D by a spring E whose lower end bears against a bracket E the button E being screwed on to the spindle to facilitate assembly. The conical enlargement E thus normally cuts off communication between the interior of "the upper part C and a conduit E leading to the breather port D.

An intermediate spider E is provided for guiding and steadying the spindle E 7 When the pillar has been extended, say, by raisingthe upper part C to the maximum height, as limited by a restricting collar H shown in Figure 2, substantially all the liquid will be contained in the lower pillar part or cylinder A. .The liquid pressure within the cylinder A due to the weight of the upper pillar part C together with such load as it may be carrying exerts a pressure on the valve E in the upward direction and thus firmly maintains it on its seat E thereby preventing flow of liquid from the cylinder, A to the valve cannot be opened in this way. It is necessary first to take the weight of the upper pillar part C and its load before the button E can be pressed down to open the valve E. Thus, in order to lower the upper part this must first be grasped and its weight taken whereupon the finger button E can be pressedjdown to open the valve E against the action of the spring E6. Since liquid can now how from the cylinder A past the valve E and through the bore E into the upper pillar part, this can be lowered to the desired level, the air displaced from the interior of the upper part C escapingpast the seating E and throughthe conduit E and breather port D? to the atmosphere. It will, however, be seen that immediately the hand is removed the valve E is closed by the spring E and the upper part C will come to rest, the valve E being then firmly held closed by the liquid pressure. All possibility of the upper pillar part C suddenly sliding down within the 'cylinder'A and thus subjecting the load to a sudden jar is'thus obviated Whilst the height of the pillar can be readily and accurately adjusted, if desired, by one hand.

" When it is desired to raise the upper pillar part 7 C, this can be done by merely grasping the upper ,ing through the breather port D and flowing past the conical seating E? into the upper partC. When the pillarhas been raised as desired, the

upper part C will remain in the adjusted'position since as soon as the weight of this part together with its load is released the valve E is automatically closed by the spring M and is firmly held closed by the resulting liquid pressure within the cylinder A.

' It will be seen that the conical seating E not only serves to control the flow of air to and from the interior of the upper part C but also prevents the escape of liquid when the pillar as a whole is laid down horizontally or is inverted. V

In the modified construction illustrated in Figure 3, the lower end of the upper pillar part C is furnished with a plug J having a cavity J and a seating J with which cooperates aball valve J The ball J is loaded by a spring K .the lower end of which bears against a plate K having a central aperture K and secured to the plug J by studs K which also secure in position two cup leathers K and K arranged back to back., The valve J is manually controlled by a release device comprising a spindle L therlower end of which lies on or adjacent to'the ball J whilst the upper end passes freely-through .the plug D and isfurnished with a finger button E With this construction the valve J is normally. pressed on its seat J by 'the liquid pressure in the cylinder A beneath the cup leathers K and K If now it is desired to lowerthe upper part C together with its load this can only be done by taking the weight of the upper part C and pressing on the button E whereby the valve J is moved from its seat J against the action of the spring K. Liquid can now fiow from the lower pillar part or cylinder A past the valve J into the upper part C. As soon as the button E is released the valve J will be closed by the spring K and the upper part C together with its load will come to rest. 7

It will be appreciated that though in both the constructions above described the breather port is automatically controlled by movemnt of the valve release device, an independent breather port may be provided which is closed, for example during transit, by a plug which can be removed after the support has been erected.

The maximum speed of lowering and raising of the upper part of. the support may be determined by suitably dimensioning the valve-controlled port or passage through which the liquid flows between the upper and lower pillar parts, this speed of lowering and raising being also governed by the viscosity of the liquid employed. Further, though the dimensions of the control valve are preferably suchv that for lowering the upper pillar part the weight of this parttogether with" its load must be taken before the valve can be opened, the valve may be so dimensioned that the valve'can be opened by a downward pressure on the release device without simultaneously supporting the upper pillar part. It will however be appreciated that even with'the latter construction as soon as the hand is removed from the release device the valve will close and the upper pillar part will come to rest.. W

Figure 4 is a diagrammatic representation of a modified arrangement in which the upper pillar part is constituted'by a piston rod N passing through .a stufiing box Oat the upperend of the lower pillar part P. A valve R- is carried at the lower end of a rod R passing freely through the rod Nfand through a piston S carriedthereby and generally similar to the piston described with reference to Figure 2. A finger button R.

is screwed to .the upper end of the rod R 8. I

spring R tending to maintain the valve R in its closed position, i. e. so as to prevent liquid flowing from one side of the piston S to the other through a passageT and ports T in the rod N. A breather passage V is formed in the stuffing box 0, a plug being preferably provided for closing this passage during transit of the pillar.

Though the invention has been more particularly described as applied to a tripod suitable for supporting photographic apparatus, the invention may be applied to any pillar support of the type set forth.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a vertically adjustable supporting pillar, in combination, a lower pillar part constituting a hydraulic cylinder, and upper pillar part, a piston carried by the upper pillar part and arranged to reciprocate within the lower pillar part, a valve carried by the upper pillar part and held in its closed position by the liquid pressure beneath the piston, a manually operated release device for the valve on the upper pillar part, the said release device also controlling a breather port in the upper pillar part, and a loading spring tending to maintain the release device in a position in which it not only closes the valve but also the breather port.

2. In a vertically adjustable supporting pillar, in combination, a lower pillar part constituting a hydraulic cylinder, an upper pillar part, a piston carried by the upper pillar part and arranged to reciprocate within the lower pillar part, a valve carried by the upper pillar part and held in its closed position by the liquid pressure beneath the piston, a low tension spring tending to hold the valve in its closed position, and a manually operated release device for the valve on the upper pillar part, the said spring tending to maintain the release device in a position in which it not only closes the valve but also a breather port in the upper pillar part.

3. In a vertically adjustable supporting pillar, in combination, a lower pillar part constituting a hydraulic cylinder, a hollow upper pillar part, a piston carried by the upper pillar part and arranged to reciprocate within the lower pillar part, a valve carried by the upper pillar part and controlling the communication between the cylinder beneath the piston and the interior of the upper pillar part, the valve being held in its closed position by the liquid pressure beneath the piston, a manually operated release device for the valve on the upper pillar part, and a loading spring which tends to maintain the release device in a position in which it not only permits the valve to close but also closes a breather port in the upper pillar part.

4. In a vertically adjustable supporting pillar the combination of a lower pillar part constituting a hydraulic cylinder, a hollow upper pillar part adapted to telescope with said lower pillar part, said upper pillar part having one opening through which its interior is adapted to communicate with the lower pillar part and a second opening in the top through which its interior is adapted to communicate with the atmosphere, a piston fixed to said upper pillar part and having an opening in axial alignment with said first opening in the upper pillar part, valves in each of said openings adapted to open and close simultaneously and be held in closed position by the liquid pressure beneath the piston, and a manually operated release device for the valves.

5. In a vertically adjustable supporting pillar the combination of a lower pillar part constituting a hydraulic cylinder, a hollow upper pillar part operating in said lower pillar part as a piston, said upper pillar part having an opening through which its interior is adapted to com- 5 municate with the lower pillar part and a breather port through which its interior is adapted to communicate with the atmosphere, 2; Valve in said opening and held in its closed position by the liquid pressure beneath the upper pillar part, a second valve in the breather port adapted to open and close said breather port simultaneously with the opening and closing of said first valve and be held closed by the liquid pressure in the lower pillar part, and a manually operated release for the valves to allow the interior of the pillar parts tocommunicate with each other and the atmosphere.

6. In a vertically adjustable supporting pillar the combination of a lower pillar part constituting a hydraulic cylinder, a hollow upper pillar part operating in said lower pillar part as a ram, said upper pillar part having an opening through which its interior is adapted to communicate with said lower pillar part and a breather port through which its interior is adapted to communicate with the atmosphere, a valve in said opening, a valve in said breather port,

a single valve stem connecting said twovalves whereby the two valves are adapted to open and close the opening and the breather port simultaneously, said valves held in their closed position by the liquid pressure in the lower pillar part, and a manually operated release for the valves.

7. In a vertically adjustable supporting pillar the combination of a lower pillar part constituting a hydraulic cylinder, a hollow upper pillar part operating in said lower pillar part as a ram, said upper pillar part having an opening through which its interior is adapted to communicate with said lower pillar part and a breather port through which its interior is adapted to communicate with the atmosphere,

a valve in said opening, a valve in said breather port, a single valve stem connecting said two valves whereby the two valves are adapted to open and close the opening and the breather port simultaneously, said valves held in their closed position by the liquid pressure in the lower pillar part, spring pressing means normally forcing said valves into their closing positions, and a manually operated release device for the valves.

8. In a vertically adjustable supporting pillar the combination of a lower pillar part constituting a hydraulic cylinder, a hollow upper pillar part operating in said lower pillar part as a ram, said upper pillar part having an opening through which its interior is adapted to' communicate with said lower pillar part and a breather port through which its interior is adapted to communicate with the atmosphere, a valve in said opening, a valve in said breather port, a single valve stem connecting said two valves whereby the two valves are adapted to open and close the opening and the breather port simultaneously, said valves held in their closed position by the liquid pressure in the lower pillar part, spring pressing means normally forcing said valves into their closing positions, a manually operated release device for said valves, and a manually operated locking means adapted to lock the upper and lower pillar parts in any desired position of adjustment relative to one another.

9. In a vertically adjustable supporting pillar the combination of a lower pillar part constituting a hydraulic cylinder, a hollow upper pile lar part adapted to reciprocate in said lower pillar part in the manner of a ram, said upper pillar part having an opening through which its inte rior is adapted to communicate with said lower pillar part and a breaher port through which its interior is adapted to communicate with theatmosphere, a valve in said opening and held in its closed position by the pressure in the lower pillar part, a manually operated release device for the valve, spring pressing-means normally forcing said release to a position wherein it closes the valve, and suitable means for manually locking said upper' pillar part in any position of adjustment relative to said lower pillar part.

WALTER BUCKSTONE.

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