US2364481A - Shear developer - Google Patents

Description

Dec. 5, 194.4. J. F. SEILER 2,364,481

SHEAR DEVELOPER Filed Dec. 7, 1945 2 Sheets-Sheet l Patented Dec. 5, 1944 SHEAR DEVELOPER James F. Seilcr, Washington, D. 0., assignor to American Wood-Prescrvers Association, a corporation of Illinois Application December 7, 1943.

14 Claims.

The invention relates to an improvement in apparatus adapted for making the construction of my Patent 2,022,693, issued December 3, 1935. In that patent is described a structure made up of wood and concrete in which are employed shear developers adapted to partiallyreceive and distribute the loads carried by the structure. It is a purpose of the present invention to provide an improved form of shear developer. Since these devices are disposed as connecting units between the concrete and wood, it is essential that they engage both and form a satisfactory connection. This requires the developers to be secured into the wood in such a Way as to have sure strong seats .and extend out sufficiently to be securely embedded in the concrete when it is applied. 1 It has been found that this may be done most effectively by employing a specially shaped shear developer as set out herein...

The shear developers in general are set in or across a trough made by three pieces ofwood, the middle one being set below or inwardly of the edges of the adjacent members. In order to sheet a strong-setting, the shear developer must engage the piece of wood at the bottom of the trough and also at its sides must engage the extending edges of the wood at the side of the trough. It has been found that this may be done efliciently by employing a shear developer especially adapted to this end and also so as to cross and close almost the entir area of the trough and at the same time extend therebeyond and be free to be engaged by the concrete when put in place.

In order to insure better holding in the wood, the shear developers may be provided with irregularities or projections at some or all of the areas which are buried in the Wood.

In order to make the shear developer better resist the stresses in the completed structure, it may be dished or bent or deformed especially at the areas engaged by the concrete and more especially about the holes if present.

An additional purpose of the present invention is to provide means for conveniently handling the shear developers during manufacture, trans: portation and installation. This may conveniently consist of a hole formed at a predetermined part in the shear developer so as to act as an index or guide to the proper placing of it in the wooden base. The hole may also furnish a seat for a bolt or spike passing therethrough and entering the wood and being buried in the concrete to further reinforce the shear developer against movement during pouring of the concrete and construction activities and also in the com- Serial No. 513,292

pleted structure which may thus be made more sturdy.

An improved tool for grooving the seats for the shear developers is also included.

This application is a continuation-in-part of my application Serial No. 351,007, filed August 3, 1940.

In the accompanying drawings, Figure 1 is a front elevation of one form of shear developer in place in a trough between pieces of wood which are shown in section. Fig. 2 is a fragmentary plan view of a portion of a blank from which may be made a plurality of shear developers. Fig. 3 is a front elevation of a tool which may be conveniently used to form seats for shear developers in the Wood which is shown in section. Fig. 4 is a fragmentary vertica1 section on the line ll of Fig. 3. Fig. 5 is a view similar to Fig. 1 showing another form of shear developer. Fig. 6 is a vertical sectionon line 5-6 of Fig. 5 showing a spike in place, and Fig. '7 is a section on the line 'L-T of Fig. 5.

The trough into which the shear developers are set is normally about as wide as it is deep and it is desirable that the developer have a sturdy sure engagement with the bottom and with both sides of the trough. One element which may determine the strength of engagement may be how deep into the Wood the developer enters. It has been found that a pointed end must go much further into the wood to obtain a comparable seating than if the end is obtuse or wider. It has also been found that an inclined seat is more easily made in the sides of the trough with such an end. The shear developer H) is made triangular in shape but With one point omitted forming a straight edge at H. Preferably the shape will be that of a trapezoid in the form of a truncated isosceles triangle, the apex being cut off parallel to the base. This truncated end is embedded a suitable depth in the wood H at the bottom of the trough giving a wide grasp on the wood. By being embedded to a slight depth it may extend nearly entirely across the bottom of the trough. In this position the sides of the shear developer will be embedded through most of the remainder of their extent in the Wooden side walls E5 of the trough as indicated at l3. This may give a strong engagement with the wood to hold the shear developer more or less certainly in place and so allow it to form a more or less sturdy connection with the concrete to be put in place. The base M of the triangle and a small area adjacent thereto extend beyond the edges of the side walls 15 of the trough and are free to be embedded in concrete to be applied. The concrete also enters the trough and makes contact with the entire surface of the shear developers I ex cept the portions buried in the walls l5 and the bottom 82 of the trough.

The shear developer near its base is provided with a hole [6 which may act as a key and aid in holding the concrete. It will be noted that the form of shear developer shown leaves, when installed, small triangular areas IT at the bottom corners of the'trough unfilled and concrete settling intothese to some extent may act as keys and assist in holding the concrete and to preserve the continuity of concrete on both sides of the shear developer.

Because of their peculiar shape the shear developers l0 may be economically made by cutting or stamping or the like from a strip or sheet of suitable thickness without substantial loss of material by being formed and separated as shown in Fig, 2 where the edge of each shear developer fully adjoins the edge of an adjacent shear developer.

Large numbers of shear developers are used in each structure and the hole I6 is found a convenient means of fastening them together for shipping and handling during manufacture, transportation, storage and installation. Unskilled labor may be used for installation since the hole I 6 may be used as a guide or index as it may indicate the edge of the device which extends from the trough and is to be entirely covered with concrete.

As shown in Fig. 6, a spike or nail 35 may be passed through the hole and driven into the bottom wood member l2. This tends to hold the shear developer rigidly in place and at the same time the spike may furnish additional anchorage for the concrete.

The shear developer may be made of suitable material to stand the strains to which it is put, being preferably of structural grade steel. It may be desirable to have the shear developer plated or coated such as by galvanizing or dipping in zinc or other protective coverings. For such procedure the hole l6 forms an easy and convenient means for handling during coating.

To further reinforce or strengthen the shear developer, it may be deformed or dished as shown at 36 in Figs. 5, 6 and 2. dished portion are present, desirable to have the hole of the shear developer.

The shear developer may be installed by being it may or may not be IS in the dished part suitably positioned and driven in place and, to

aid in such procedure, the sides and truncated end may be sharpened if desired. It is found better and more convenient in general, however, to employ a tool for cutting or grooving the seats into which the shear developers are to be placed. Such a tool is illustrated in Figs. 3 and 4. There is provided a blade corresponding in size and shape to the shear developer to be installed. This blade may .be made of hardened cutting metal and is sharpened at its edges 19 and at its truncated end 20 and is held in a slot 2| in a handle 22, the end 33 of which may be so shaped that it may be driven by a manual sledge hammer or in a standard pneumatic hammer or other power-operated device. The handle also carries guides 23, one on each side of the blade I8. Each guide has a tongue 24 slightly narrower than the width of the trough between the members I5 but somewhat longer than. the depth of the trough. At its upper end each tongue 24 is provided with When both hole and laterally extending projections 25 to provide for proper connection to the handle and to brace the device. When the tongue 24 reaches the bottom member l2 a sufllcient groove has been made to receive the shear developer. The bottom of the handle 22 finds a seat 26 in the guides 23. Bolts 21 hold the guides 23 onto the handle 22 and pass through enlarged holes 28 in the blade l8. A bolt 29 is shown holding the guides 23 against the blade is and passing through an enlarged hole 30 in the blade. Thus pressure from the handle 22 is put on the blade l8 at its upper edge in the slot 2| and no strain is carried by the bolts 21 and 29 to the blade [8. When desired, the bolts 21 and 29 may be removed and guides and blades of other sizes and shapes may be substituted to correspond with whatever shear developers are being installed in whatever troughs are being used.

To aid in holding the shear developer in place in its seat, cuts 31 may be provided at points in their margins or edges l3 which are adapted to be set in the wood. The portions 38 below the cuts may be pushed or turned out of the plane of the shear developer. As indicated especially in Fig. 7, such cut and turned or pushed out portions may pass through the wood resiliently and finally seat themselves in such a way as to press into the wood and grip it so as to better resist the strains and hold against withdrawal or displacement. While not essential it may be desirable that the cut portions be not pushed out farther than the thickness of the material as shown.

The shear developers may be plain as shown in Fig. 1, or may have holes, dished portions and gripping portions turned out at cuts in their edges as illustrated in Figs. 5 and 7, or any one or more of these extra elements may be omitted.

Since the dished portion 36 extends 0n the same 'side of the shear developer as the turned out portions 38, even the shear developer with all the details shown in Fig. 5 may be made by a single operation of the die from the strip of metal, as indicated in Fig. 2.

Forms and dimensions may be varied to meet desires and conditions of use without departing from the invention.

I claim:

1. A shear developer comprising a truncated isosceles triangular metal plate with a perforation near the base and substantially equidistant from the sides.

2. A shear developer for wood and concrete structure comprising a truncated isosceles triangular metal plate adapted to have an area near its base extending into the concrete and its truncated end and most of its sides embedded in the wood.

3. A shear developer for a wood and concrete structure comprising a truncated isosceles triangular metal plate adapted to be seated in a trough in the wood with its truncated end embedded in the bottom of the trough and most 'of its sides embedded in the sides of the trough and the remainder embedded in the concrete with a portion adjacent the base extending beyond the mouth of the trough and provided with a hole in the extending portion.

4. A shear developer seat grooving tool comprising a blade corresponding in size to the shear developer and sharpened at its edges, a pair of guides one on each side of the blade, a tongue on each guide fitting in the trough into. which the shear developer is to be seated and engaging the material at the bottom of the trough and limiting the entrance of the blade, and a handle carrying the blade and the guides and adapted when hit to cause the blade to groove the seat for the developer.

5. In a device of the class described, a trun- ,cated isosceles triangular metal plate adapted to be seated in a trough of wood with its truncated end and part of its sides embedded in the bottom of the trough and most of the rest of its sides embedded in the sides of the trough.

6. A shear developer comprising a truncated isosceles triangular metal plate with a reinforcing depression near the base and between the sides.

7. A shear developer comprising a truncated isosceles triangular metal plate with a perforation near the base and substantially equidistant from the sides, a reinforcing depression, and portions at the margins cut and pushed out.

8. A shear developer for a wood and concrete structure comprising a truncated isosceles triangular metal plate adapted to be seated in a trough in the wood with its truncated end embedded in the bottom of the trough and most of its sides embedded in the sides of the trough and the remainder embedded in the concrete with a portion adjacent the base extending beyond the mouth of the trough and portions at wood-embedded points out and pushed out to engage the wood, and a reinforcing depression in the concrete embedded portion.

9. A shear developer for a wood and concrete structure comprising a' truncated isosceles triam gular metal plate adapted to be seated in a trough in the wood with its truncated end embedded in the bottom of the trough and most of its sides embedded in the sides of the trough and the remainder embedded in the concrete with a portion adjacent the base extending beyond the mouth of the trough and portions at wood-embedded points cut and pushed out to engage the wood.

10. A shear developer for wood and concrete structures comprising a truncated isosceles triangular metal plate adapted to have an area near its base extending into the concrete and its truncated end and most of its sides embedded in the wood, portions at embedded points cut and pushed out to en age the wood. 1

11. A shear developer for wood and concrete structures comprising a truncated isosceles triangular metal plate adapted to have an area near its base extending into the concrete and provided with a reinforcing depression and its truncated end and most of its sides embedded in the wood and portions at embedded points pushed out to engage the wood.

12. A shear developer for wood and concrete structures comprising a truncated isosceles triangular metal plate adapted to have an area near its base provided with a hole and extending into the concrete and its truncated end and most of its sides embedded in the wood, a. spik through the hole and engaging the wood.

13. A shear developer for a wood and concrete structure comprising a truncated isosceles triangular metal plate adapted to be seated in a trough in the wood with its truncated end embedded in the bottom of the trough and most of its sides embedded in the sides of the trough and the remainder embedded in the concrete with a portion adjacent the base extending beyond the mouth of the trough and provided with a hole in the extending portion, and a spike through the hole and seated in the bottom of the trough.

14. A shear developer for a wood and concrete structure comprising a truncated isosceles triangular metal plate adapted to be seated in a trough in the wood with its truncated end embedded in the bottom of the trough and most of its sides embedded in the sides of the trough and the remainder embedded in the concrete with a portion adjacent the base extending beyond the mouth of the trough and provided with a hole in the extending portion and portions at points embedded in the wood cut and pushed out to engage the wood, and a spike through the hole and seated in the bottom of the trough.

JAMES F. SEILER.

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