Abstract:
A tightening device for adjusting the degree of tautness of a strapping member. The device comprises: a base; a first member attached to and extending at a first angle from a first side of the base; a second member attached to and extending at a second angle from a second side of the base, the members being in an opposed spaced apart relationship and cooperating with the base to define an interior; a first slot formed in a distal end of the first member with respect to the base, the first slot configured to receive the strapping member therethrough; a second slot formed in a distal end of the second member with respect to the base, the second slot configured to receive the strapping member therethrough in coordination with the opposing slot; and a tightening element configured for coupling the strapping member to the device, the tightening element for collecting and retaining a selected length of the strapping member within the interior; wherein adjustment of the tightening element modifies the length of the strapping member extending between the slots and thereby collected in the interior.

Description:
This application claims priority from U.S. provisional application Ser. No. 60/484,646, filed Jul. 7, 2003, the contents of which are herein incorporated by reference. 

   The present invention relates to structural building components, and in particular to bracing elements of frame assemblies for buildings. 
   BACKGROUND OF THE INVENTION 
   Residential and commercial buildings contain walls and floors typically assembled as frame assemblies with a series of vertical and horizontal structural members, also known as framing elements. In order for the frame assemblies to withstand vertical and horizontal loading, either static or dynamic, shear braces and/or cladding are typically attached to the framing elements on at least one side of the frame assemblies. 
   In the case of light framed wall assemblies such as steel framed walls, a flat steel strap known as a flat strap brace is attached on a diagonal (or perpendicular) to the framing elements, thereby increasing the stiffness of the frame assembly to resist lateral and racking loads. These flat strap braces are generally manually attached to opposing corners of the frame assembly, which can lead to undesirable pockets of slack strap material located between the adjacent framing elements. One disadvantage with this installation procedure is that it is difficult to install the flat straps as stretched taut, in order to be effective in resisting any applied loads, and therefore special tools or jigs are commonly used in attaching and thereby pre-tensioning or otherwise making taut the straps on the frame assembly. 
   One solution for controlling the tautness of diagonal strapping members is given in U.S. Pat. No. 6,185,898 by Pratt. Pratt describes modifying a wall assembly to incorporate a pair of laterally opposed vertical supports, which are used to attach a corresponding strap thereto. Each of the supports have an aperture that is sized to receive the straps by means of a cooperating force distributing member and a strap alignment member. Both members are positioned in the aperture to align and distribute loading from the tensioned straps. However, one disadvantage with Pratt&#39;s strapping arrangement is that it requires modification of the adjacent wall framing members to provide appropriate aperture to accommodate the force distributing and strap alignment members. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a strap tightening device to obviate or mitigate at least some of the above presented disadvantages. 
   Residential and commercial buildings contain walls and floors typically assembled as frame assemblies with a series of vertical and horizontal structural members, also known as framing elements. In order for the frame assemblies to withstand vertical and horizontal loading, either static or dynamic, shear braces and/or cladding are typically attached to the framing elements with straps on at least one side of the frame assemblies. One disadvantage with current flat strap braces is that it is difficult to install the straps as stretched taut, in order to be effective in resisting any applied loads, and therefore special tools or jigs are commonly used in attaching and thereby pre-tensioning or otherwise making taut the straps on the wall. Contrary to present brace and strap systems, a tightening device is provided for adjusting the degree of tautness of a strap. The device comprises: a base; a first member attached to and extending at a first angle from a first side of the base; a second member attached to and extending at a second angle from a second side of the base, the members being in an opposed spaced apart relationship and cooperating with the base to define an interior; a first slot formed in a distal end of the first member with respect to the base, the first slot configured to receive the strap therethrough; a second slot formed in a distal end of the second member with respect to the base, the second slot configured to receive the strap therethrough in coordination with the opposing slot; and a tightening element configured for coupling the strap to the device, the tightening element for collecting and retaining a selected length of the strap within the interior, wherein adjustment of the tightening element modifies the length of the strap extending between the slots and thereby collected in the interior. 
   According to the present invention there is provided a tightening device for adjusting a degree of tautness of a strap, the device comprising: a base adapted for connecting to the strap; a first member extending from a first side of the base; a second member extending from a second side of the base, the members being in an opposed spaced apart relationship and cooperating with the base to define a device interior, a first slot located in a distal end of the first member, the first slot adapted to receive the strap therein; and a second slot located in a distal end of the second member, the second slot adapted to receive the strap such that a length of the strap extends between the first slot and the second slot; wherein during use, the strap will be retained within the device interior by connecting the strap to the base, such that the length of the strap extending between the slots is increased. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features of the preferred embodiments of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings wherein: 
       FIG. 1   a  is a perspective top view of a tensioning device; 
       FIG. 1   b  is a perspective top view of the tensioning device of  FIG. 1   a;    
       FIG. 2  is a side view of the device of  FIG. 1   b;    
       FIG. 3  is a side view of a wall assembly including the device of  FIG. 1   a;    
       FIG. 4  is a section view taken at line  4 - 4  of  FIG. 2 ; 
       FIG. 5  is a view of the section view of  FIG. 4  with the tensioning device in use; 
       FIG. 6   a  is an assembled side view of the tensioning device of  FIG. 1   a;    
       FIG. 6   b  is a further side view of the tensioning device of  FIG. 6   a  with the tensioning device in use; 
       FIG. 7   a  is a further embodiment of the device of  FIG. 1   a;    
       FIG. 7   b  is a still further embodiment of the device of  FIG. 1   a;    
       FIG. 7   c  is a still further embodiment of the device of  FIG. 1   a;    
       FIG. 7   d  is a still further embodiment of the device of  FIG. 1   a ; and 
       FIG. 8  is a still further embodiment of the device of  FIG. 1   a.    
       FIG. 9   a  is a perspective view of a further embodiment of the device of  FIG. 1   a;    
       FIG. 9   b  is a perspective view of another embodiment of the device of  FIG. 1   a;  and 
       FIG. 10  is a manufacturing process of the device of  FIG. 1   a.    
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1   a , a tightening device  10  has a base  12  with a pair of opposing members  14 , providing such as but not limited to a U-shaped cross-section, to define an interior  15 . Each of the members  14  has a slot  16  through which a strap  18  (see  FIG. 1   b ) is inserted. Opposing sides  19  of the strap  18  can be inserted into corresponding entrances  26  of the slots  16 , in order to position the strap  18  in the interior  15 . The base  12  has a hole  20  for receiving a fastener  22 , such as but not limited to a threaded bolt or screw. It is recognised that the base  12  could also have a marker or dimple (not shown), rather than the hole  20 , for aiding the placement of the fastener  22 , such as a self tapping screw. It is recognised that the marker/dimple or hole  20  is an example of adapting the base  12  for attaching to the strap  18 . Other examples of adaptation could include tolerances such as flatness and dimensions of the base  12  to accommodate gathering of the strap  18  within the interior  15  and attachment to the base  12 . 
   Referring to  FIG. 1   b , a corresponding hole  24  (to hole  20 ) is formed in the strap  18  to receive the fastener  22  therethrough, in order to gather a portion of the strap  18  in the interior  15  of the device  10  (see  FIG. 6   b ). For example, the hole  20  can be preformed in the base  12  and the hole  24  can be formed in the strap  18  by the fastener  22 , such as but not limited to a self tapping screw. It should be noted that the fastener  22  is used as a tightening element for collecting a selected length of the strap  18  in the interior  15  to modify the tightness of the strap  18 , as further described below. The device  10  can be manufactured from material such as but not limited to bent sheet metal material formed as a single piece, an assembly of individual components joined through mechanical/metalurgical means (fasteners, welding, adhesive, etc . . . ), molded (such as using plastics material) or cast as a one piece unit, or a combination thereof 
   Referring to  FIG. 2 , each of the slots  16  of the device  10  has the entrance  26  for providing access of the strap  18  to a slot interior  28 . The entrances  26  are in a spaced apart opposed relationship on respective ends of the members  14 . The width of the entrance  26  can be less than the slot interior  28  so as to provide a notch  30  or abutment at one end of the slot  16 . The notch  30  inhibits the strap  18  from becoming dislodged from the slot  16  once inserted therein, and to assist in holding the device  10  in place once positioned on the strap  18 . The slot  16  also has a stop  32  or abutment located at the other end opposite the entrance  26 , for inhibiting undesirable rotation of the device  10 , when the fastener  22  is rotated during gathering of the strap  18  in the interior  15  (see  FIG. 6   b ). Once the device  10  is positioned on the strap  18  (as shown in  FIG. 1   b ), the stops  32  are contacted by the sidewalls of the strap  18  due to initial rotation of the device  10  during installation of the fastener  22  to the base  12 . Once contacted, the stops  32  inhibit further rotation of the device  10  with respect to the strap  18 , thereby assisting in holding the device  10  in position during further tightening of the fastener  22 . The cooperation of the strap  18  with the stops  32  assists in fastening of the strap  18  to the device  10 , such that the device  10  preferably does not have to be continually manually held in position by the installer of the device  10 . It is recognised that the configuration of the entrances  26  and stops  32  can be as shown (see  FIG. 1   a ) for a clockwise rotation of the fastener  22 , or for a counter clockwise rotation (not shown). It is further recognized the device  10  can also have slots  16  without entrances  26 , whereby the strap  18  is threaded sequentially through the opposing slots  16  from one member  14  to the other. However in this case, the slots  16  would have the stops  32  located at both respective ends. 
   Referring to  FIG. 3 , a pair of the devices  10  are installed on a corresponding pair of straps  18 . First, one end of each of the straps  18  is attached to a respective corner  34  of a frame assembly  36 . Then the straps  18  are then pulled straight and the opposite ends are attached to the opposite corners  34  of the frame assembly  36 . The straps  18  are fastened at corners  34  of the frame assembly  36  as in known in the art. The devices  10  are then installed over the straps  18  and between framing elements  40  and then secured to the straps  18  as described below. The straps  18  are installed to inhibit shearing or racking of the frame assembly  36  due to imposed loads such as indicated by reference numeral  38 . It is recognized that the assembly  36  could also be adapted to construction of floor assemblies (not shown). It is also recognized that multiple devices  10  could be installed on one respective strap  18 , if desired. Further, a series of holes  19  can be preformed on the strap  18  to accommodate placement of the devices  10  on the straps  18  in predetermined locations, rather than using self tapping screws as compared to machine screws. 
   Referring to  FIG. 4 , initial installation of the strap  18  adjacent to framing elements  40 , such as but not limited to those used in light steel frame construction, can result in forming pockets  42  of slack strap material between the elements  40 . These pockets  42  of strap material can reduce the effectiveness of the straps  18  in inhibiting the induced loads  38 . Referring to  FIG. 1   b , the separation distance of the opposed members  14  is preferably sufficient so as to accommodate the width of the strap  18 , so as to permit positioning the strap  18  within the interior  15  of the device  10  prior to inserting the strap  18  in the slots  16 . Therefore, once the strap  18  is initially positioned within interior of the device  10 , the device  10  can be rotated counterclockwise with respect to the strap  18  so as to insert the sidewalls of the strap  18  through the entrances  26  of the slots  16 . Further counterclockwise rotation of the device  10  with respect to the strap  18 , approximately by an angle of 90 degrees, feeds the remaining strap  18  width through the entrances  26  so as to retain the strap  18  squarely within the slots  16 . Subsequent initial clockwise rotation of the device  10  within the slots  16  will cause contact of the sidewalls of the strap  18  with the stops  32 , as described above. 
   Referring to  FIG. 5 , respective devices  10  have been secured to each of the straps  18  by inserting the fastener  22  through the strap  18  and into the base  12  of the device  10 . It is noted that tightening of the fastener  22  acts as a tightening element, which increases the tautness of the strap  18  by gathering excess or slack pockets  42  as gathered strap material  44  into the interior  15  between the base  12  and members  14  of the device  10  (see  FIG. 6   b ) and thereby acts to remove or otherwise inhibit the formation of the strap pockets  42 . Further, once the pockets  42  are removed in the strap  18  between the elements  40 , further tightening of the fastener  22  produces tension in the strap  18 . 
   Referring to  FIG. 9   a , the device  10  can also have reinforcement elements  900  positioned on the base  12 . The reinforcements  900  are for transferring bending forces and other experienced loadings from the base  12  to the members  14 , so as to strengthen the base  12  to inhibit buckling or general structural integrity failure of the base  12 . These loads can be static loads applied to the base  12  during application of the device  10  to the strap  18  (see  FIG. 1   b ) and/or dynamic loads experienced during racking of the frame assembly  36  (see  FIG. 3 ) once the device  10  is installed. These reinforcements  900  can be separate elements attached to the main body material (e.g. sheet metal stock) of the device  10 , and/or be embossments formed during the manufacturing process of the device  10  (see  FIG. 10 ). The reinforcements  900  preferably extend along the base  12  from one member  14  to the opposing member  14 . Further, the reinforcements can be attached, or otherwise formed, directly at the ends  904  to both the base  12  and the adjacent member  14 . It is recognised that the dimensions and placement of the reinforcements  900  on the base  12  are done so as to not inhibit the connection of the fastener  22  to the base  12 , as well as to not inhibit or otherwise interfere with the positioning of the strap  18  within the interior  15  of the device  10  (see  FIG. 6   b ). It is recognised that the reinforcements  900  can be positioned within the interior  15  and/or on the underside  901  of the base  12 . It is further recognised that the reinforcements  900  can extend transversely across the base  12  with respect to the members  14  (as shown) or can extend diagonally (not shown), for example, across the base from one corner of the base  12  to the other corner of the base  12 . 
   Referring again to  FIG. 9   a , the device  10  can also have additional tabs  902  formed as an extension of the base  12 . The tabs  902  are for strengthening or otherwise reinforcing the base  12  to resist base loadings experienced by the device  10  during interaction with the strap  18 . The tabs  902  extend at an angle with respect to the base  12 , for example 90 degrees, and can either be an extension of the base  12  sheet material or a separate component attached to the base  12  sheet material, for example such as but not limited to welding. Further, the sides  906  of the tabs  902  can be connected to the adjacent members  14  so as to further assist in the transfer of the base  12  loadings to the members  14 . It is noted that the tabs  902  can be used in combination with the reinforcements  900 , if desired. It is recognised that the dimensions and placement of the tabs  902  on the base  12  are done so as to not inhibit the connection of the fastener  22  to the base  12 , as well as to not inhibit or otherwise interfere with the positioning of the strap  18  within the interior  15  of the device  10  (see  FIG. 6   b ). It is recognised that the tabs  902  can be positioned adjacent the interior  15  and/or projecting towards the underside  901  of the base  12 . 
   Referring to  FIG. 9   b , other reinforcements  908  can be used such that they are positioned both on the base  12  and attached to the adjacent respective member  14 . These reinforcements  908  may not extend from member  14  to member  14  along the base  12 , rather are used as reinforcements between the base  12  and the adjacent member  14 . The reinforcements  908  can be used to help resist bending forces between the members  14  and the base  12 , such that the manufactured angle between the base  12  and the members  14  is retained or otherwise inhibited from changing during operation of the device  10 . For example, testing of the device  10  has shown under certain loading conditions that the distal ends of the members  14  bend away from the base  12 , resulting in an angle greater that 90 degrees between the base  12  and member  14 . This bending can contribute to integrity failure of the device  10  and in particular of the base  12 . It is recognised that the dimensions and placement of the reinforcements  908  on the base  12  are done so as to not inhibit the connection of the fastener  22  to the base  12 , as well as to not inhibit or otherwise interfere with the positioning of the strap  18  within the interior  15  of the device  10  (see  FIG. 6   b ). It is recognised that the reinforcements  908  can be positioned within the interior  15  and/or on the underside  901  of the base  12 . It is noted that the tabs  902  and/or reinforcements  900  can be used in combination with the reinforcements  908 , if desired. 
   Referring to  FIGS. 6   a  and  6   b , operation of the device  10  once installed on the frame assembly  36  (see  FIG. 3 ) first places the straps  18  in the slots  16  (see  FIG. 1   b ), such that a portion of the strap  18  is placed in the interior  15 . The fastener  22  is then inserted through the strap  18  and base  12  of the device  10  and tightened to gather excess strap material  44  into the interior  15  and also to produce a desired tension or tautness in the straps  18 . An angle “A” between the members  14  and base  12  preferably remain approximately 90° to resist bending moments of the members  14  during tightening and thereby resists deformation of the device  10  that could result in decreasing induced tension in the strap  18 . It is noted that device  10  operates to remove pockets  42  of slack strap material (see  FIG. 5 ) and provide for installation of flat and substantially tensioned straps  18  as shown in  FIG. 6   b . The amount of tightening of the fastener  22  with respect to the base  12  can provide for tension control of the straps  18 . It is recognized that with diagonally attached straps  18  (see  FIG. 3 ), the device  10  can assist in squaring of the frame assembly  36 . 
   Referring to  FIG. 10 , an example manufacturing process  700  of the device  10  is provided. At step  702 , a stock sheet material  600  is rolled to the desired thickness of the device  10  to accommodate expected forces experienced during operation. At step  704 , punches  602  are used on the material  600  to make the slots  16  in the desired configuration (see  FIG. 7   a,b,c,d ). At step  704 , the sheet material  600  is bent so as to form the base  12  and the members  14 . At step  706 , tools  604 ,  606  and a die  608  can be used to form the reinforcements  900 ,  908  (for example). For example, the reinforcement  908  is formed as an embossment by tool punch  604  and the reinforcement  900  is formed as an embossment by tool punch  606 . Once formed, individual devices  10  from the formed material  600  can be sheared at step  708  to produce the finished devices  10 . It is recognised that additional or replacement reinforcement elements (i.e. tabs  902  and reinforcements  900 ,  908 ) can be added to the formed device  10  through mechanical attachment processes (e.g. welding). It is also recognised that a portion or all of the device could be made by a casting or molding process as is known in the art. 
   Referring to  FIGS. 7   a ,  7   b ,  7   c , and  7   d , alternative embodiments of the device  10 , namely  110 ,  210 ,  310 , and  510  are shown. Device  110  has slots  16  which have entrances  26  situated on the same side for both of the members  14 . Device  210  has shortened slots  16 , such that the slot interior  28  does not extend for the full width of the strap  18  (not shown). Device  310  has slots  16  with opposing entrances  26 , however, the angle A between the base  12  and the members  14  is greater than 90° . Device  510  has an open slot  516  in the distal end of each member  514  for accepting the strap  18  (not shown). Further, the device  110  can also have an embossed portion  422  to strengthen the region of the base  12  around a hole  424  to help reduce the tendency of the fastener  22  to pull out of the hole  424  when tightened. It is recognized that embossing  423  could also be used to strengthen other parts of the device  410  including but not limited to members  14   a,b  to help provide additional stiffening to reduce the tendency of the members to divide from desired angle A when the fastener  22  is tightened. Further, an indent  27  can be situated in each member  14  for positioning of the strap  18  (not shown). 
   Referring to  FIG. 8 , an alternative device  410  has the base  12  with members  14   a ,  14   b  having opposing slots  16 . The member  14   a  has a clamping arm  412  attached to the top by means of a flexible hinge  414 . The member  14   b  has a series of tabs  416   a,b,c  positioned on either side and below the slot  16 . The arm  412  has a fulcrum  418  for contacting the straps  18  (not shown) when inserted in the interior  15 , whereby the arm  412  acts as the tightening element to induce collection of the strap  18 . 
   In operation of the device  410 , the arm  412  is depressed into the interior  15  such that the fulcrum  418  contacts the strap  18 . Pressure is further applied to the arm  412  to force it into the interior  15 , such that an edge  420   a  and of the arm  412  engages with the first set of tabs  416   a , thus gathering excess material  44  of the strap  18  into the interior  15  and edge  420   b  contacts the strap  18 . Subsequent depression of the arm  412 , such that the edge  420   a  and engages tabs  416   b , acts to increase the amount of material  44  of the strap  18  gathered in the interior  15  and thereby helps to increase the degree of tautness of the strap  18 . It is noted that the orientation tabs of  416   a,b,c  allow the arm  412  to be depressed into position, yet retain the arm  412  once placed. Accordingly, the arm  412  acts as a tightening element to remove slack pockets  42  from the straps  18  and to develop varying degrees of tension tautness in the strap  18 . 
   The devices  10 ,  110 ,  210 ,  310 ,  410  can be manufactured from 0.033 in and 0.044 in and 0.1 in steel roll stock with for example a 36 ksi yield strength. The roll stock can be Zn coated or Al—Zn coated or painted to resist corrosion. The devices  10 ,  110 ,  210 ,  310 ,  410  can be cold formed by bending a sheet of roll stock to the desired cross-sectional shape (see  FIG. 1   a ), and the slots  16  and hole  20  can be punched or otherwise formed prior to and/or after forming. It is noted that the body (base  12 , member  114 ) of the devices  10 ,  110 ,  210 ,  310 ,  410  are preferably manufactured from a requisite thickness of roll stock so as to promote primary failure in the straps  18  rather than the device  10 ,  110 ,  210 ,  310 ,  410 . It is also noted that a washer (not shown), such as a concave or convex shaped washer, could be inserted between the strap  18  and the head of the fastener  22  to distribute stress loading there-between. 
   Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto.