US3693929A

US3693929A - Hanger device useful in forming concrete structural slabs

Info

Publication number: US3693929A
Application number: US107059A
Authority: US
Inventors: Sidney L Martin
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-01-18
Filing date: 1971-01-18
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26

Abstract

A hanger device useful in conjunction with temporary decking or forms for pouring concrete structural slabs, such as roofs or floors, is constructed of a channel bearing a curved, pivoting tongue-shaped member. The channel is adapted to hold a joist for supporting the temporary decks on which the concrete is poured. The tongue-shaped member protrudes upwardly through a slot in the top of the channel and rests at its downwardly curved end on a preformed support, such as a joist or beam. Rotational movement of the tongue-shaped member is prevented by a locking pin cooperating therewith. In forming the slab, the poured concrete covers the protruding portion of the tongue-shaped member, the preformed support and the form decking. After hardening of the concrete, the hanger device carrying the supporting joist is readily removed by withdrawing the locking pin and applying a downward force on the channel is the vicinity of the tongue shaped member, resulting in a slight vertical displacement of the tongue-shaped member from the concrete contiguous thereto and rotation thereof out of the concrete without binding. The device may then be reused in forming another slab.

Description

United States Patent Martin 51 3,693,929 [4 1 Sept. 26, 1972 [54] HANGER DEVICE USEFUL IN FORMING CONCRETE STRUCTURAL SLABS [72] Inventor: Sidney L. Martin, 6520 S.W. 79th Court, Miami, Fla. 33143 [22] Filed: Jan. 18, 197 1 211 App]. No.: 107,059

Related US. Application Data [63] Continuation-in-part of Ser. No. 850,735, Aug.

18, 1969, abandoned.

[52] US. Cl ..249/25 [51] Int. Cl ..E04g 11/38 [58] Field of Search ..249/23-25, 28

[56] References Cited UNITED STATES PATENTS 583,099 5/1897 Tompkins ..249/25 1,779,735 10/1930 Harm ..249/25 1,186,614' 6/1916 Smith ..249/25 2,012,616 8/1935 Miller ..249/25 FOREIGN PATENTS OR APPLICATIONS 428,208 5/1935 Great Britain ..249/23 Primary Examinerl. Spencer Overholser Assistant Examiner-Ben D. Tobor AttorneyMeyer Neishloss and Alvin E. Ring 5 7 ABSTRACT A hanger device useful in conjunction with temporary decking or forms for pouring concrete structural slabs, such as roofs or floors, is constructed of a channel bearing a curved, pivoting tongue-shaped member. The channel is adapted to hold a joist for supporting the temporary decks on which the concrete is poured. The tongue-shaped member protrudes upwardly through a slot in the top of the channel and rests at its downwardly curved end on a preformed support, such as a joist or beam. Rotational movement of the tongue-shaped member is prevented by a locking pin cooperating therewith. In forming the slab, the poured concrete covers the protruding portion of the tongueshaped member, the preformed support and the form decking. After hardening of the concrete, the hanger device carrying the supporting joist is readily removed by withdrawing the locking pin and applying a downward force on the channel is the vicinity of the tongue shaped member, resulting in a slight vertical displacement of the tongue-shaped member from the concrete contiguous thereto and rotation thereof out of the concrete without binding. The device may then be reused in forming another slab.

PATENTEBWB I912 3.693.929

SHEET 2 OF 2 //WA/mQ. S/DA/EY 4. MART/N HANGER DEVICE USEFUL IN FORMING CONCRETE STRUCTURAL SLABS This application is a continuation-in-part of my copending application, Ser. No. 850,735, filed Aug. 18, 1969, now abandoned.

SUMMARY OF THE INVENTION This invention relates to a hanger device useful in forming substantially horizontal concrete structural slabs, such as floors and roofs. More particularly, it comprises support means having inner and outer surfaces, such as an inverted channel or a rectangular or tubular conduit, adapted to hold a joist for supporting temporary forms or decks for the concrete and carrying a movable tongue-shaped member protruding above and below the top of the support means through a slot adjacent one end thereof. The portion of the tongueshaped member protruding above the support means is curved, defines an arc which is substantially a segment of the circumference of a circle, and is adapted to rest at its downwardly curved end on a preformed support for the concrete slab. The device is provided with locking means preventing rotational movement of the tongue-shaped member during pouring of the concrete while the curved end of the member is resting on the preformed support and is being covered by the concrete. A circular pivot means is fixed to the portion of the tongue-shaped member within the support means immediately adjacent the slot and interiorly of the tongue-shaped member. The pivot means cooperates with the tongue-shaped member to rotate the member free of the hardened concrete without binding upon removal of the locking means.

THE DRAWINGS In the drawings FIG. 1 is a plan view of the hanger device of the invention;

FIG. 2 is a side elevation of the device of FIG. 1;

FIG. 3 is a front elevation of the device shown in FIGS. I and 2;

FIG. 4 is a view, partly in section, taken along the line IV-IV of FIG. 3 in the direction of the arrows;

FIG. 5 is a view similar to that of FIG. 4 showing withdrawal of the hanger device and its tongue-shaped member from a hardened concrete slab; and

FIG. 6 is a fragmentary perspective view showing the hanger device and accompanying form joists and decking in position for pouring a concrete structural slab.

DETAILED DESCRIPTION Referring to the drawings, the hanger device of the invention comprises a support means having inner and outer surfaces, such as the inverted channel shown generally at 10. The inverted channel has a top portion 11 and side portions 12. Typically, the channel can be made of A: inch steel and can have a length of about 14 inches, both dimensions depending upon the load to be carried The interior of the channel may be shaped to fit over the ends of wood joists 13, for example, 2 X 6 or 2 X 8 inch joists, or the ends of suitable steel joists (not shown) which support the form decks or decking 14 on which a concrete slab is to be formed.

,. the inner surface of the top 11 of the inverted channel to the surface of the clamping plate may be varied to accommodate the particular size of joist being used.

Adjacent that end of the channel to which the joist is fastened, there is provided a movable tongue-shaped member 19 which is adapted to rest or bear at its downwardly curved end 20 on a preformed support 21 for the concrete slab 22. The preformed support can be a flush-sided concrete beam or a steel beam having projecting flanges, such as an l-beam. As best shown in FIGS. 1 and 4, the tongue-shaped member protrudes above and below the top of the channel through a slot 23 in a continuation 24 of the top 11 of channel 10. As will be described later, the continuation 24 also forms part of a hanger device spacing assembly which is attached to the sides of the inverted channel.

The portion of the tongue-shaped member 19 protruding above the channel defines an are which is substantially a segment of the circumference of a circle, as shown in FIGS. 2 and 4. A substantially vertical position limiting lug 26 is fixedly secured, as by welding, at position 27 on the inner (concave) surface of the curved protruding portion of the tongue-shaped member 19 approximately midway of the horizontal distance between the slot 23 and the end 20 of the tongue-shaped member. An integral continuation 26a of lug 26 is also welded to the lower end 28 of the portion of the tongue-shaped member terminating within the inverted channel 10. The position 27 at which the limiting lug is welded to the member 19 is not critical; the length of the tongue-shaped member overhanging the support 21 should be sufficient to prevent slipping of the end 20 thereof off the preformed support 21 after the entire hanger assembly and decking are in place and the concrete has been poured. By way of example, for an inverted channel having a length of about 14 inches, and the tongue-shaped member and limiting lug being fabricated from relatively heavy steel of about X 1% inches, the horizontal distance from the end 20 of the tongue-shaped member and the outer surface of the vertical portion 26 of the lug can be 1% inches.

As shown in FIGS. 4 and 5, a cylindrical pivoting lug 29 is fixedly attached, as by welding, across the width of that portion of the inner surface of the tongueshaped member 19 disposed within the inverted channel l0 and immediately adjacent slot 23, whereby the tongue-shaped member 19, all of lug assembly 26-26a, and pivoting lug 29 pivotally move or rotate as a unit. A removable locking pin 30 is loosely fitted through openings 31 in sides 12 of the inverted channel to prevent such rotational or pivoting movement until necessary, as described later.

Lug assembly 26-26a performs several functions. First, the vertical portion 26 serves to bear laterally against the preformed support 21, and to define the limiting distance at which the downwardly curved end 20 of the tongue-shaped member rests on the preformed support. Second, the portion 26a, angled as shown toward the portion of the tongue-shaped member 19 disposed within channel and welded to said member at its lower end 28, cooperates with said member and locking pin 30 to permit the latter to prevent substantial movement, particularly rotation, of the tongue-shaped member while the locking pin is in place. Third, lug assembly 26-26a absorbs and distributes the stresses upon the tongue-shaped member when the latter is in locked position, locking pin 30 also assisting in this function, thus tending to prevent distortion or breaking of the curved portion of the tongueshaped member because of the heavy load of joist 13, form decking l4 and concrete 22.

When the hanger device is assembled with supporting joists 13 and form decks 14 with the locking pin 30 in place, as shown for example in FIG. 6, the pivoting lug 29 will bear against the inner surface of continuation 24 of the top 11 of inverted channel 10 immediately adjacent the slot 23, as shown in FIG. 4. At the same time, locking pin 30 will bear against the inner surface of the angle formed .by the tongue-shaped member 19 and continuation 26a of lug 26 within inverted channel 10 to prevent movement of the tongue-shaped member and its integral lug 26-260. When the locking pin is removed for removing the hanger device after the poured concrete has hardened sufficiently, free play of the assembly of the tongue-shaped member and lug 26-26a in relation to inverted channel 10 is permitted. The downward force then applied to channel 10 by reason of its own weight and the weight of joist 13 causes pivoting lug 29 to continue to bear against the inner surface of continuation 24 of channel 10 but to roll along said surface from a position immediately adjacent slot 23 in a direction displaced horizontally therefrom toward the end of channel 10 away from the joist 13. The result is to cause the upper (convex) surface of tongue-shaped member 19 to be displaced slightly vertically from the contiguous surface of hardened concrete immediately above it and to pivot the tongue-shaped member out of the hardened concrete without binding thereto.

Pivoting lug 29 performs an important function in the removal operation of the hanger device of the invention from the hardened concrete because it translates the downward movement of channel 10 into rotational movement of tongue-shaped member 19 out of the concrete. As has been indicated, the portion of the tongue-shaped member protruding above channel 10 is curved to define an arc which is substantially a segment of the circumference of a circle, such as a quarter of a circle. The relationship between the cross-sectional diameter of cylindrical pivoting lug 29 and the radius of curvature of the described portion of the tongueshaped member protruding above the top of channel It) is also important to successful removal of the tongueshaped member from the hardened concrete. As has been described, upon removal of locking pin 30, pivoting lug 29 rolls along the inner surface of continuation 24 and provides a migrating center of rotation for the tongue-shaped member. lf the cross-sectional diameter of lug 29 is too small in relation to the radius of curvature of the portion of the tongue-shaped member protruding through and above the top of channel 10, the tongue-shaped member will not be withdrawn completely from the,hardened concrete. If the diameter of lug 29 is too large in relation to the radius of curvature of the described portion of the tongue-shaped member, rotation of the tongue-shaped member will be excessive, causing binding of the upper surface of the tongue-shaped member against the overlying concrete. Therefore, the ratio of the diameter of lug 29 to the radius of curvature of the described portion of the tongue-shaped member must be sufficiently large to rotate the tongue-shaped member completely out of the hardened concrete but not so large that binding against the concrete occurs. From the above and the following description, a desired ratio sufficient to rotate the tongue-shaped member completely out of the hardened concrete will be apparent to those skilled in the art.

The radius of curvature of the described portion of the tongue-shaped member, particularly when considering the sub-portion between the downwardly curved end 20 thereof and the outer surface of the vertical portion 26 of the position limiting lug, is relatively large so as to result in almost horizontal movement of the tongue-shaped member out of the hardened concrete. It is to be noted, however, that such movement is not entirely horizontal, experience having shown that the small amount of hardened concrete 32 formed between the top of joist 21 and the inner surface of the tongue-shaped member, which is thin and weak, is many times left intact but sometimes may be readily and easily broken during withdrawal of the tongue-shaped member from the space it has formed in the concrete. As noted above, the radius of curvature of the portion of the tongue-shaped member embedded in the concrete is so correlated with the cross-sectional diameter of pivoting lug 29 as to permit the abovedescribed slight vertical displacement and pivoting of the tongue-shaped member completely out of the hardened concrete without binding. By way of example, for a hanger device of the dimensions previously given, the above-mentioned radius of curvature of the tongue-shaped member is 1% inches and the cross-sectional diameter of the cylindrical pivoting lug is k inch.

For the purpose of further facilitating withdrawal of the tongue-shaped member, it is desirable, but not essential, slightly to taper a portion of the tongue-shaped member between the downwardly curved end 20 thereof and the outer surface of the vertical portion 26 of the position limiting lug.

The apparatus of the present invention severs the adhesive bond between the upper surface of tongueshaped member 19 and the contiguous overlying concrete 22 by applying two components of stress against such bond. The first component is a downward tensile stress and the second is a torque or shearing stress. These two stress components are applied concurrently against the bond and tend to cooperate in fracturing the bond. The rotational (torque) or shearing stress is a highly advantageous feature of the present invention since shearing forces are especially effective in fracturing adhesive bonds between unlike materials. Of course, these same stresses also apply to that portion 32 of the hardened concrete contiguously underlying the inner (concave) or lower surface of tongue-shaped member, although here the tensile stress component is in an upward direction. However, as has been noted earlier, lay 32 of the hardened concrete is thin and weak and may be easily fractured at times during withdrawal of the tongue-shaped member.

Reference has been made to continuation 24 of the top 11 of inverted channel 10. As stated, continuation 24 forms part of a hanger device spacing assembly attached to the sides 11 of the inverted channel. Such assembly itself is an inverted channel having vertical sides 32 integral with top 24 and horizontal flanges 33 integral with sides 32. The entire assembly is attached, as by welding, to the sides 12 of the inverted channel where the top 11 thereof ends.

The invention will now be described with reference to its use in forming a concrete structural slab, such as a roof or floor. First, a joist 13 of suitable size and length is fitted into two of the hanger devices described above, one at each end of each joist, and the clamping plates 17 are fastened to hold the joist firmly in place. As will be apparent, the joist is not inserted so far into channel as to interfere with movement of the tongue-shaped member. Depending upon the span of the concrete slab to be formed, several joist and hanger device assemblies are employed. For example, spans of 8 to 10 feet can be employed, and the spacing between joist centers may vary from 16 to 32 inches.

Each joist and hanger device assembly is then positioned on the preformed supports 21 for the concrete slab to be formed, the hanger and joist assembly resting on the preformed supports at each end of the hanger device at downwardly curved ends 20. At this point is is desirable to ascertain that all locking pins are firmly in place. Since several joist and hanger device assemblies are employed, it is also desirable to space them equidistantly from each other to distribute the load of concrete evenly. To this end, wooden spacer strips 34, for example 2 X 2 or 2 X 4 inch, of equal length are placed on flanges 33 of the hanger devices and the hanger device and joist assemblies are firmly fitted against the ends of the spacer strips. Next, wooden spacer strips are placed between each protruding tongue-shaped member 19 to assure a substantial continuity of the poured concrete slab between those members and to eliminate the work required for cutting appropriate spacing either in the continuous strip 36, to be described, or in the form deck 14. These strips 35 may have a thickness of 1 inch, a width equal to the horizontal distance between the edge of the outer surface of the vertical portion 26 of the position limiting lug abutting preformed support 21 and the outermost edge of the portion of the tongue-shaped member 19, protruding above channel 10, and a length sufficient to fit snugly against each tongue-shaped member and limiting lug assembly. Continuous wooden strips 36 are then placed snugly abutting strips 35. The width of strips 36 is desirably sufficiently less than the width of strips 34 to allow the edge of form decking 14, which may be inch plywood, to rest on spacer strips 34 and permit nailing of the decking thereto if necessary. It will be apparent that strips 36 can be omitted, if desired, by merely widening decking l4. Desirably, the thickness of the

strips

34, 35 and 36 in relation to the position of horizontal flanges 33 on the hanger device is such as to leave a small distance or offset 37, on the order of inch or so, between the top surface of the preformed support 21 and the top surface of

strips

35 and 36. In this manner, after the concrete slab has been poured and has hardened, relative movement of the slab and preformed supports is prevented.

After the form decking 14 is put into place, the entire assembly of spacer strips and form decking is secured in place by nailing, using as few and as small nails as possible. Desirably, nailing should be confined to securing

strips

35 and 36 to strip 34, nailing of the plywood decking to strip 34 being required only when a severely warped plywood sheet is used as decking.

It will be apparent to those skilled in the art that the assemblies described and shown, for example, in FIG. 6 are duplicated on the other side of the preformed support 21 and as many times as necessary with other preformed supports to provide a unitary concrete slab spanning as many such supports as required and as may be limited in area and span by the particular job under construction.

After the desired number of assemblies are in place, concrete is poured and allowed to harden to form the structural slab. After the concrete has reached its required strength, each hanger device-supporting joist assembly is ready to be removed. To accomplish this, locking pin 30 is first removed, if necessary by knocking it out. If the channel and joist assembly does not begin to lower because of its weight when the pin is removed, a sharp downward rap and pull may be applied to clamping plate 17. In either case, as the above downward force is applied to the hanger device in the vicinity of the tongue-shaped member 19, that member will drop slightly and pivot out of the hardened concrete as previously described. Normally, as the one end of the hanger device is removed from the hardened concrete, continued lowering of the hanger device-joist assembly will cause rotation out of the concrete of the tongue-shaped member of the hanger device at the other end of the joist without removal of the locking pin. However, if joist lengthor an obstruction prevents sufficient rotation of the tongue-shaped member at such other end, removal of the locking pin and the other procedure described above is followed.

The hanger device of this invention permits the pouring of concrete structural slabs having a thickness of 4% or more inches spanning 8 to 10 or more feet between supports, although it may, of course, be used for thinner slabs of considerably smaller span. It eliminates the costly shoring, wedging and nailing required for form decks for such thick slabs, along with the labor costs required to erect and remove them. In addition to the above savings of lumber and scaffolding, the hanger device of this invention has the advantage of being readily removed from hardened concrete without binding and is capable of repeated reuse despite any roughness of the surface metal of the portion of the tongue-shaped member protruding above the inverted channel, or build-up of concrete film thereon.

What is claimed is:

1. An apparatus useful in conjunction with a preformed support and form decking for pouring a substantially horizontal concrete structural slab supported by said preformed support, comprising:

support means for holding a joist for supporting said form decking,

said support means having inner and outer surfaces and a slot adjacent one end thereof,

a movable tongue-shaped member carried by said support means and protruding through said slot above and below the top of said support means, the portion of said tongue-shaped member protruding above said support means being curved, defining an. arc which is substantially a segment of the circumference of a circle, and being adapted to rest at its downwardly curved end on said preformed support,

locking means, for preventing movement of said tongue-shaped member during pouring of the concrete while the downwardly curved end of said member is resting on said preformed support and the curved protruding surfaces of said member are being covered by the concrete,

circular pivot means fixed to the portion of said tongue-shaped member within said support means immediately adjacent said slot interiorly of said member, said pivot means being in contact with the inner surface of said support means,

said circular pivot means having a cross-sectional diameter the ratio of which to the radius of curvature of said portion of the tongue-shaped member protruding above said support means permits rolling migration of the circular pivot means along the inner surface of said support means in a horizontal direction toward the end of said support means and away from said joist upon removal of said locking means,

whereby after said concrete has been poured and has hardened said tongue-shaped member may be rotated completely out of the hardened concrete without binding upon removal of said locking means.

2. The apparatus of claim 1, wherein said support means is an inverted channel.

3. The apparatus of claim 1, wherein said circular pivot means is a cylindrical lug.

4. The apparatus of claim 1 wherein a position limiting lug is attached at its upper end to said curved protruding portion of the tongue-shaped member and at its lower end to that end of the tongue-shaped member within said support means.

5. An apparatus useful in conjunction with a preformed support and form decking for pouring a substantially horizontal concrete structural slab supported by said preformed support, comprising:

an inverted channel having a slot in its top adjacent one end thereof,

said inverted channel being adapted to hold a joist for supporting said form decking,

a movable tongue-shaped member carried by said inverted channel and protruding through said slot above and below the top of said inverted channel,

the portion of said tongue-shaped member protruding above said inverted channel being curved and having a downwardly turned end defining an arc which is substantially a quarter segment of the circumference of a circle, and being adapted to rest at its downwardly curved end on said preformed support,

the portion of said tongue-shaped member protruding below the top of said inverted channel having an end terminating within said channel,

a position limiting lug having a vertical portion which is attached at its upper end to the portion of said ton ue-sha ed member rotrudin abov said invered chari nel at aboutt e mldpo tlon of the concave surface of said tongue-shaped member,

the remaining portion of said position limiting lug being angled toward, and being attached at its lower angled end to, that end of said tongueshaped member terminating within said inverted channel,

locking means formed by a removable locking pin in contact with the surfaces of the angle formed by the end of said tongue-shaped member and the end of the position limiting lug attached thereto within said inverted channel,

a cylindrical pivoting lug attached across the width of that portion of said tongue-shaped member within said inverted channel and immediately adjacent said slot,

said cylindrical pivoting lug bearing on the inner surface of the top of said inverted channel,

said cylindrical pivoting lug having a cross-sectional diameter the ratio of which to the radius of curvature of said portion of said tongue-shaped member protruding above said inverted channel permits rolling migration of the cylindrical pivoting lug along said inner surface of the top of the inverted channel in a horizontal direction toward the end of said inverted channel and away from said joist upon removal of said locking pin,

whereby after said concrete has been poured and has hardened said tongue-shaped member may be rotated completely out of the hardened concrete without binding.

Claims

1. An apparatus useful in conjunction with a preformed support and form decking for pouring a substantially horizontal concrete structural slab supported by said preformed support, comprising: support means for holding a joist for supporting said form decking, said support means having inner and outer surfaces and a slot adjacent one end thereof, a movable tongue-shaped member carried by said support means and protruding through said slot above and below the top of said support means, the portion of said tongue-shaped member protruding above said support means being curved, defining an arc which is substantially a segment of the circumference of a circle, and being adapted to rest at its downwardly curved end on said preformed support, locking means for preventing movement of said tongue-shaped member during pouring of the concrete while the downwardly curved end of said member is resting on said preformed support and the curved protruding surfaces of said member are being covered by the concrete, circular pivot means fixed to the portion of said tongue-shaped member within said support means immediately adjacent said slot interiorly of said member, said pivot means being in contact with the inner surface of said support means, said circular pivot means having a cross-sectional diameter the ratio of which to the radius of curvature of said portion of the tongue-shaped member protruding above said support means permits rolling migration of the circular pivot means along the inner surface of said support means in a horizontal direction toward the end of said support means and away from said joist upon removal of said locking means, whereby after said concrete has been poured and has hardened said tongue-shaped member may be rotated completely out of the hardened concrete without binding upon removal of said locking means.

2. The apparatus of claim 1, wherein said support means is an inverted channel.

5. An apparatus useful in conjunction with a preformed support and form decking for pouring a substantially horizontal concrete structural slab supported by said preformed support, comprising: an inverted channel having a slot in its top adjacent one end thereof, said inverted channel being adapted to hold a joist for Supporting said form decking, a movable tongue-shaped member carried by said inverted channel and protruding through said slot above and below the top of said inverted channel, the portion of said tongue-shaped member protruding above said inverted channel being curved and having a downwardly turned end defining an arc which is substantially a quarter segment of the circumference of a circle, and being adapted to rest at its downwardly curved end on said preformed support, the portion of said tongue-shaped member protruding below the top of said inverted channel having an end terminating within said channel, a position limiting lug having a vertical portion which is attached at its upper end to the portion of said tongue-shaped member protruding above said inverted channel at about the midportion of the concave surface of said tongue-shaped member, the remaining portion of said position limiting lug being angled toward, and being attached at its lower angled end to, that end of said tongue-shaped member terminating within said inverted channel, locking means formed by a removable locking pin in contact with the surfaces of the angle formed by the end of said tongue-shaped member and the end of the position limiting lug attached thereto within said inverted channel, a cylindrical pivoting lug attached across the width of that portion of said tongue-shaped member within said inverted channel and immediately adjacent said slot, said cylindrical pivoting lug bearing on the inner surface of the top of said inverted channel, said cylindrical pivoting lug having a cross-sectional diameter the ratio of which to the radius of curvature of said portion of said tongue-shaped member protruding above said inverted channel permits rolling migration of the cylindrical pivoting lug along said inner surface of the top of the inverted channel in a horizontal direction toward the end of said inverted channel and away from said joist upon removal of said locking pin, whereby after said concrete has been poured and has hardened said tongue-shaped member may be rotated completely out of the hardened concrete without binding.