US2711806A - Expandible supporting beams for use in building - Google Patents

Description

W. H. SMITH June 28, 1955 EXPANDIBLE SUPPORTING BEAMS FOR USE IN BUILDING Filed. July 51 1950 United States EXPANDIBLE SUPPORTING BEAMS FOR USE IN BUILDING This invention relates to expandible supporting beams for use in building of the kind in which two or more parts slide relatively to each other to provide for varying lengths of span.

These supports are principally used in the construction of concrete floors and are called in the trade telescopic centers.

In one form which has been used there is a central member made of sheet metal and two end members which slide within the central member.

With this arrangement it is not possible for the fully extended length to be much more than one and a half times the minimum length.

In the telescopic centres of the present invention there is an outer member in which slides at one or both ends an inner member and there is a further inner member which slides within the first-mentioned inner member or members.

In the case of a central outer member, an inner member at each end, and a further inner member in each of: these there will be in all five members.

Further inner members may be provided so that there will be more than five members in all.

The outermost member is so shaped at the end that it bears against a wall, girder or other permanent support at the level of the top of the beam.

In the accompanying drawings:

Fig. 1 shows an elevation of an end of one form of center according to the invention.

Fig. 2 shows in section to larger scale part of the center shown in Fig. 1.

Fig. 3 shows in section to larger scale a further part thereof,

Fig. 4 shows a bottom plan view of the end of the center shown in Fig. 2.

Fig. 5 shows a central cross section.

The support is made of sheet steel and is triangular in section with apex downwards. It has a central member 1 in which fit and slide two intermediate members 2, in each of which is fitted and slides an end member 3 provided at the top with a tapered projecting lip for engagement with the wall or other permanent support.

The ends of the members 1 and 2 are cut away at a downward angle of about 45 degrees.

To give additional stiffness to the members 2, 3, the tops thereof are provided with central grooves 5, 6 While the sides of said members have ribs 7, 8 and 17.

The intermediate members 2, 3 are provided with stops 9, 10, respectively, to limit the amounts of their relative sliding movements; said members are provided with keel- like projections 11, 27, secured by bolts 18, 19 at intervals at the apex to increase bending resist ance (see Fig. 5). The keel-like projection 11 bears against a pressure pad 20.

The stops 9 engage detachable screw stop elements 23 and the stops 10 engage removable stops 26. When the stops 23, 26 are removed the parts can be withdrawn for inspection and repair.

Pads 21 and 24 are carried by the members 2, 3, respectively, and are adjusted by shims 22, 25, respec- "atent tively, to cause the members 2, 3 to keep contact with each other on their top surfaces.

When these telescopic centers are used for construction of the concrete floors there is a great frictional resistance between the top of the centers and the underside of the floors. It is then necessary to use a prising or forcing tool to withdraw the projecting lips 4 from the supports. To accomplish this function I provide dismounter bars 12 and movably secure them to the underside of the top portions of the outermost members 3. The bottoms of the members 3 are each provided with a hole 15 while each bar is provided with a recess 47. A bent lever 13 is employed to slidably move the members relative to each other. The top of each lever 13 is provided with a pin 14 which passes through the hole 15 and engages the recess 47 in the bar 12. By means of the bent lever 13, the end of bar 12 is forced against the vertical face of the wall or support and applying counterpressure via the hole 15 acting as a fulcrum on member 3 to telescope member 3 into member 2, and thus withdraw the lip 4 from the wall or support.

Springs 16 are connected with the ends of the bars 12 and retract the bars inwards of the telescopic centers.

Although a certain specific embodiment of the invention has been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim:

1. An expandibie supporting beam for use in building, comprising a plurality of telescopic members including a central member and two end members, each end member having an opening adjacent the outermost end thereof, a bearing portion on each of said end members for respective mounting on spaced supports, means for removing said bearing portions from the supports and including dismounting bars, each bar being provided with a recess facing a corresponding opening; said bars being mounted for longitudinal sliding movement in the outer ends of the end members and movable between inoperative positions within said members and operative positions extending beyond the ends of said end members to abut the supports on which said members bear to force the respective bearing portions from said supports, and means extending through an opening in one of said end members into a recess in one of said bars for moving each of said dismounter bars between said positions.

2. An expandible support as defined in claim 1, wherein a spring is provided in each end member and connected with the respective bar and normally retracting said bar to inoperative position.

3. An expandible supporting beam as set forth in claim 1, wherein an intermediate member is telescopically mounted between the central and end members; each of said members being of triangular cross-section with the base uppermost to form the support and having keel-like reinforcing elements along their apexes.

References Cited in the file of this patent UNITED STATES PATENTS 157,560 Werden Dec. 8, 1874 1,996,887 Smith Apr. 9, 1935 2,202,096 Dell et a1. May 28, 1940 2,239,315 De Vigier Apr. 22, 1942 2,386,161 Hawes Oct. 2, 1945 FOREIGN PATENTS 405,279 Great Britain Jan. 29, 1934

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