US3099049A

US3099049A - Lift beam assembly

Info

Publication number: US3099049A
Application number: US192102A
Authority: US
Inventors: Robert L Webb
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-05-03
Filing date: 1962-05-03
Publication date: 1963-07-30
Anticipated expiration: 1980-07-30

Description

July 30, 1963 R, 1 WEBB 3,099,049

LIFT BEAM ASSEMBLY Filed May 5, 1962 44 4 ROBERT l.. WEBB y 34. JNVENTOR. 3%! v FIGA BY fsa, M

AGENT 3,099,049 LIFT BEAM ASSEMBLY Robert L. Webb, Oklahoma City, Okla. Filed May 3, 1962, Ser. No. 192,102 3 Claims. (Cl. 2li- 16) The present invention relates to tornado and bomb shelters, or the life, and more particularly to a means for opening the stairwell cover therefor.

Most shelters and particularly bomb and fall-out shelters are equipped with a stairwell for egress and ingress which is usually equipped with a relatively heavy door. The doors are horizontally disposed or nearly so and it is desirable that some means be provided for assisting the occupants in opening the door from the outside or inside of the shelter.

'It is, therefore, the principal object of this invention to provide -a spring actuated lift assembly which will bear a major portion of the weight of the entrance door for a bomb shelter, or the like, in the opening and closing action of the door.

Another object is to provide a device of -this class which is relatively small and yet lsturdily constructed and which will last substantially the life of the shelter.

An additional object is to provide a device of this class which may be easily connected to the stairwell and door of existing shelters.

Still another object is to provide a door lifting device which includes latch means for holding the door in opened position.

The present invention accomplishes these and other objects by interconnecting a pair of tubular members to a door and stairwell. The pair of members are mounted in telescoping relation with a helical expansion spring surrounding the inner member for normally urging the members apart.

Other objects will be apparent from the following description when taken in conjunction with the accompanying single sheet of drawings, wherein:

FIGURE l is a side elevational View, partly in section, illustrating the device in door opened position and showing, by dotted lines, the relative position of the door and device when the door is closed;

FIGURE 2 is a ltop plan View of the device illustrating the manner of its connection with the door;

FIGURE 3 is a horizontal cross-sectional View, partly in elevation, taken substantially along the line 3 3 of FIG. l; and,

FIGURE 4 is a fragmentary vertical cross-sectional View taken substantially along the line 4 4 of FIG. 1.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

'In the drawings:

'I'he reference numeral 10 indicates one side of a bomb shelter stairwell having a wall portion 12 integral with a step 14 `and having `a door 1'6 hingedly connected, as at 18, to the upper and outer edge surface of the stairwell wall 12. The reference numeral indicates the device, or hft beam, as a whole, which is cylindrical in general conguration and includes an outer tubular member 22 which telescopingly receives an inner tubular member 24. The upper end of the outer member 20, las seen in FIG. 1, is provided with a transversely extending anchor pin or bolt 26 which is extended through a transverse arcuate slot ."29 formed inthe free end portion of an arm 2S rigidly connected at its other end to the lower surface of the door 16. A pair of bushings 30, surrounding the bolt 26 on either side of the arm 2S, guide the latter into a slot 32 formed in the upper end surface of the outer member 20 when the door is in open position. A mounting tube 34 is telescopingly received within the depending end of the inner tube 24. The depending end of the mounting Patented July 30, 1963 ice tube is hemispherical in shape and is centrally apertured for engagement over the upstanding end of an anchor pin 36 inserted into the upper surface of the step 14 -adjacent the wall 12. A bearing washer 38 is interposed between the hemispherical end of the mounting tube and the upper surface of the step 14. A thrust washer 40 surrounds the mounting tube and is secured -to the depending end of the inner tube 24. The mounting tube 34 is provided with a series of transverse apertures `42 for removably receiving 'a pin 44 to adjust the length and lifting moment of the device 20 with respect to the lower surface of the door.

A helical expansion 'spring 47 surrounds the tube 24 and is interposed between the thrust washer 40 and a thrust plate 46 held in place within the upper end portion of the tube 22 by a bolt 49.

A substantially U-shaped latch 4S, having its respective leg end portions connected by a cross bar 50, is pivotally connected to the tube 22 at a selected point intermediate its ends by latch pins 52. The cross bar 50 contacts Aand engages a hook portion 54, formed on the end of a catch 56, secured to the upper edge surface of the stairwell 12. A handle portion 58, secured to the bight of the U-shaped latch 48, permits manual release of the latch from the catch. A cooperating arcuate free end edge 57 of the catch contacts the tube 22 to form a stop when the door is in open position.

When the door is in closed position, as shown by dotted lines (FIG. 1), the anchor pin 26 is positioned in the end portion of the slot 29 nearest the door 16. In this position the spring 47 is compressed and its full lifting force is utilized when the door starts its movement toward open position. The arrangement of the components `is such that the linear change of spring force during extension and compression, in door yopening and closing, acts through a moment arm of varying length. The angular position of the arcuate slot 29 increases and decreases the tension on the spring 47 and provides the correct moment through all angles of door movement and minimizes the external efort required to open the door or support the door while closing. 'Ihe device 20 retracts to become nearly flush with the wall 12 and leaves the stairwell clear when the door is in an open position. In the open position, the device lacts as a beam to hold the door in a vertical plane. A lug 59, secured to the tube 22 above the latch 48 maintains the door in open position against wind pressure on the door.

A downward and side force is exerted on the mounting pin 36 at all times. Therefore, the necessity for tension type fasteners is eliminated. Installation of the device is thereby simplified and it is particularly adaptable to existing masonry structures.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and I therefore do not wish to be coniined to the preferred embodiment shown in the drawings and described herein, further than II am limited by the scope of the appended claims.

I claim:

l. A lift assembly for a horizontal door covering a stairwell, comprising: a pair of elongated tubular members joined in telescoping relation; a helical expansion spring surrounding the innermost one of said telescoping members; mounting means pivotally connecting one end of the innermost -said member to the upper surface of one step in said stairwell, said mounting means comprising a mounting tube telescopingly received bythe depending end portion of said inner tube, said mounting tube having an apertured hemispherical depending end, an anchor pin secured by one end portion within said one step of said stairwell and projecting upwardly into said mounting tube, and a bearing washer interposed between the upper surface of said step and the hemispherical end of said mounting tube; means pivotally connecting the uppermost end of said outer member to the lower surface of said door; and latch means pivotally connected to said outermost member intermediate its ends .and releasably engaged with the Wall forming one side'of the stairwell when the door is in open position.

2. A lift assembly for a horizontal door vcovering a stairwell, comprising: a pair of elongated tubular members joined in telescoping relation; a helical expansion spring surrounding the innermost one of said telescoping members; mounting means pivotally connecting one end of the innermost said member to the upper surface of one step in said stairwell, said mounting means comprising a mounting tube telescopingly received by the depending end portion of said inner tube, said mounting tube having an apertured hemispherical depending end, an anchor pin secured by one end portion within said one step of said stairwell and projecting upwardly into said mounting tube, and a bearing washer interposed between the upper suface Vof said step `and the hemispherical end of said mounting tube; connector means pivotally connecting the uppermost end of said outer member to the lower surface of said door, said connector means comprising an arm rigidly connected at one end to the adjacent surface of said door, said arm having an arcuate slot in its free end portion, yand a bolt transversely extending through said outer member and slidably received by the slot in said ann for varying the compression of said spring during the opening and lclosing action of said door; and latch means pivotally connected to said outermost member intermediate its ends and releasably engaged with the wall forming one side of the stairwell when the door is in open position.

3. A lift assembly for a horizontal door covering a stairwell, comprising: a pair of elongated tubular members joined in telescoping relation; a helical expansion spring surrounding the innermost one of said telescoping members; mounting means pivotally connecting one end of the innermost said member to the upper surface of one step in said stairwell, said mounting means comprising a mounting tube telescopingly received by the depending end portion of said inner tube, said mounting tube having an apertured hemispherical depending end, an anchor pin secured by one end portion within said one step of said stairwell .and projecting upwardly into said mounting tube, yand a bearing washer interposed between the upper surface of said step and the hemispherical end of said mounting tube; connector means pivotally connecting the uppermost endof said outer member to the lower surface of said door, said connector means comprising an arm rigidly connected at one end to the adjacent surface of said door, said arm having an arcuate slot in its free end portion, and a bolt transversely extending through said outer member and slidably received by the slot in said `arm for varying the compression of said spring during the opening and closing action of said door; and latch means pivotally connected to said outermost member intermediate its ends and releasably engaged with the Wall forming one side of the stairwell when the door is in open position, said latch means comprising a U-shaped latch forming a handle and having its leg portions pivotally connected to opposing ysides of the outermost one of said pair of tubular members, a bar interconnecting the ends of the legs of said U-shaped latch opposite the handle, and a catch secured to said wall forming one side of Said stairwell and releasably engaged with said bar, said catch having an arcuate free end edge engagable with a peripheral portion of the outermost one of said pair of tubular members tto form a stop.

References Cited in the le of this patent UNITED STATES PATENTS 1,090,697 Eddelman Mar. 17, 1914 2,643,420 Schwarty June 30, 1953 2,939,738 Lyons June 7, 1960

Claims

1. A LIFTER ASSEMBLY FOR A HORIZONTAL DOOR COVERING A STAIRWELL, COMPRISING: A PAIR OF ELONGATED TUBULAR MEMBERS JOINED IN TELESCOPING RELATION; A HELICAL EXPANSION SPRING SURROUNDING THE INNERMOST ONE OF SAID TELESCOPING MEMBERS; MOUNTING MEANS PIVOTALLY CONNECTING ONE END OF THE INNERMOST SAID MEMBER TO THE UPPER SURFACE OF ONE STEP IN SAID STAIRWELL, SAID MOUNTING MEANS COMPRISING A MOUNTING TUBE TELESCOPINGLY RECEIVED BY THE DEPENDING END PORTION OF SAID INNER TUBE, SAID MOUNTING TUBE HAVING AN APERTURED HEMISPHERICAL DEPENDING END, AN ANCHOR PIN SECURED BY ONE END PORTION WITHIN SAID ONE STEP OF SAID STAIRWELL AND PROJECTING UPWARDLY INTO SAID MOUNTING TUBE, AND A BEARING WASHER INTERPOSED BETWEEN THE UPPER SURFACE OF SAID STEP AND THE HEMISPHERICAL END OF SAID MOUNTING TUBE; MEANS PIVOTALLY CONNECTING THE UPPERMOST END OF SAID OUTER MEMBER TO THE LOWER SURFACE OF SAID DOOR; AND LATCH MEANS PIVOTALLY CONNECTED TO SAID OUTERMOST MEMBER INTERMEDIATE ITS ENDS AND RELEASABLY ENGAGED WITH THE WALL FORMING ONE SIDE OF THE STAIRWELL WHEN THE DOOR IS IN OPEN POSITION.