Abstract:
A truss clamp for connection with a second clamp when installing truss assemblies includes a mechanism for adjustably connecting the two clamps in spaced relation. The truss clamp includes a fixed member and a rotatable member, the rotatable member having first and second ends and being pivotally connected to the fixed member intermediate the ends of the rotatable member and being rotatable between a first position wherein the first end is in confronting relation with a portion of the fixed member and a second position wherein the second end is in confronting relation with the portion of the fixed member. A holding mechanism may be disposed over a center spring action mechanism, for selectively maintaining the rotatable member in at least the second position. A method of installing trusses using a truss clamp is also disclosed.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a clamping mechanism or device and more particularly to clamping device for use with the installation of trusses for building, particularly roof trusses for peaked roofs of houses and the like. 
   BACKGROUND OF THE INVENTION 
   Truss systems are essential for supporting roofs on buildings, and peaked roofs are particularly difficult to put into place by one&#39;s self. However, labour costs encourage people to attempt to install truss systems with reduced manpower, perhaps increasing thereby a safety issue. 
   Canadian Patent File No. 2,364,466, laid open Jun. 3, 2002, of Lin et al., illustrates a truss spacer and brace which provides apparatus for spacing structural members in particular roof trusses, during construction and for permanently bracing the same structural member. The device includes a top truss tab and flanges spaced to define a slot for the truss member. 
   U.S. Pat. No. 5,884,411 granted Mar. 23, 1999 of Raber discloses a truss alignment apparatus which includes a T-shaped beam member which includes a top planar portion and a bottom planar portion extending perpendicular to the top portion. The bottom planar portion includes a plurality of beam-reception notches positioned longitudinally to it. There is also an alignment level incorporated in the apparatus. 
   U.S. Pat. No. 5,580,036 granted Dec. 3, 1996 to Browning (see also Canadian Patent File No. 2,215,954) relates to a method and apparatus for remotely securing and spacing trusses and other building frame assemblies. The apparatus is primarily comprised of a spacer having a first truss connector and a second truss connector. A pull down arrangement (example by a rope) is used to remotely engage the apparatus with a truss. In use, the apparatus is attached to a first building member which is then positioned with the apparatus attached. The apparatus is then remotely pulled down and secured to a second, adjacent building member that has just been moved into position. 
   Although the Browning device potentially permits a reduced number of people to assemble a truss system, it is a somewhat complicated device and requires some means such as a rope to activate the apparatus in order to secure the apparatus to a second adjacent building member. Ropes and the like around construction sites may be hazardous at times. 
   It would be desirable to provide a more simple and economical clamp apparatus which is operative essentially automatically once attached to a first building member to capture and temporarily secure a second adjacent building member or truss swung into place, until the second member can be finally secured with appropriate spacer members and the like. 
   SUMMARY OF THE INVENTION 
   The present invention in one aspect relates to a truss clamp device and more particularly in one aspect to a truss clamp for connection with a second clamp, wherein the truss clamp comprises means for adjustable connection with the second clamp and has a fixed member to which a rotatable member, having first and second ends, is pivotally connected intermediate the ends thereof. The rotatable member is rotatable between a first position wherein the first end is in confronting relation with a portion of the fixed member and a second position wherein the second end is in confronting relation with the portion of the fixed member. The rotatable member is selectively maintained in at least the second position and preferably in both positions. A spring mechanism in co-operation with the fixed member and the rotatable member maintains the rotatable member in both positions by an “over center” configuration relative to the pivot connection. 
   Preferably, the device includes a releasable lock mechanism to lock the rotatable member in the second position and the rotatable member is configured to maintain the lock mechanism out of lock position when it is in the first position and to automatically release the lock mechanism when it moves to the second position. A stop mechanism on the rotatable member cooperates with the fixed member to limit rotation of the rotatable member in the second position under the bias of the spring means. 
   The invention also provides a truss clamp assembly comprising a first clamp and a second clamp, the first and second clamps each having bar means adjustably connected whereby spacing between the clamps may be selectively adjusted. The first clamp has releasable clamp means adapted to be clamped to a fixed truss and the second clamp has a fixed member and a rotatable member, the rotatable member having first and second ends. The rotatable member is pivotally connected to the fixed member intermediate the ends of the rotatable member and is rotatable between a first position wherein the first end is in confronting relation with a portion of the fixed member and a second position wherein the second end is in confronting relation with the portion of the fixed member. Means selectively maintain the rotatable member in the first position and the second position, the maintaining means comprising spring means configured in relation to the pivotal connection to provide an over center action to selectively maintain the member in the first position or second position. An auxiliary clamp is provided for adjustable connection with one of the bar means and is adapted to be temporarily connected to a truss intermediate trusses to which the first and second clamps are associated in use of the clamp assembly. 
   The invention further comprises a method of installing a second truss in constructing a roof structure, wherein at least one first truss is already secured in place, each truss having a base and peak roof portion, the method including the steps of:
         providing a truss clamp comprising a first clamp, a second clamp, and means adjustably connecting the clamps in spaced relation, the spacing between the clamps being selected in accordance with desired spacing between the trusses when installed, the second clamp including a trip clamp mechanism;   detachably connecting the first clamp to a part of the peak roof portion of the secured first truss such that the second clamp extends in a direction where the second truss is to be located;   locating the base of the second truss generally parallel with the base of the first secured truss and moving the peak roof portion of the second truss into a position whereby the second truss peak roof portion engages with and trips the trip clamp mechanism of the second clamp so that the peak roof portion of the second truss is releasably held in position by the second clamp; and,   permanently securing the second truss in place by other means and removing the truss clamp for selected reuse.       

   Other aspects and features of the invention will become evident from reviewing the detailed description of preferred embodiments in conjunction with the drawings, as set forth herein. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which: 
       FIG. 1  is a schematic view of a roof truss assembly wherein two trusses are in secured position and a third is readied for being swung into place. 
       FIG. 2  is a side view of a preferred embodiment of the clamp apparatus according to the invention with a first portion of the clamp device, clamped to an already secured truss while the next adjacent truss to be secured is being swung into place toward a second portion of the clamp devices. 
       FIG. 3  is a side view of part of the clamp device of  FIG. 2  showing further movement of the adjacent truss into place for securement. 
       FIG. 4  is a side view of part of the clamp device of  FIG. 2  showing the adjacent truss temporarily secured into place with the clamp device. 
       FIG. 5  is a side perspective view from the top of the clamp device of  FIGS. 3 and 4  in its ready position as shown in  FIG. 2 . 
       FIG. 6  is a side view similar to  FIG. 2  of another, more preferred, embodiment of the invention with the clamp section in a set position for being tripped. 
       FIG. 7  is a view similar to  FIG. 3 , of the embodiment of  FIG. 6 , with the clamp section tripped and holding a truss. 
       FIG. 8  is a side view of the clamp section of  FIG. 6  looking in the direction of arrow  8  of  FIG. 6 . 
       FIG. 9  is a side view of the clamping section of  FIG. 7  looking in the direction of arrow  9  of  FIG. 7 . 
       FIG. 10  is a cross sectional view of a truss and the bar of a bar clamp illustrating an adjustable auxiliary clamp device when the inventive clamp device is configured to span or extend over an already secured truss. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred embodiments, it is understood that the invention is not limited to the disclosed embodiments. 
   Turning to the drawings,  FIG. 1  schematically illustrates a section of a building  10  having walls  12 ,  14  and  16  with walls  12 ,  14  having at least upper surfaces  20 ,  22  respectively to which trusses of assembly  24  are secured. Illustrated are first and second trusses  30 ,  32  secured to the surfaces  20 ,  22  and showing a brace  34  between the first truss  30  and second truss  32 . It will be appreciated by those skilled in the art that additional braces between the trusses  30 ,  32  could be used. A third truss  36  is shown having ends lying on surfaces  20 ,  22  and with the central section  38  of truss  36  supported by a cross beam  40  or the like, whether such beam  40  is temporary or permanently secured to walls  14  and  16 . Other wall support members can be present, but have been omitted for the sake of simplicity. 
   With truss  32  (as well as truss  30 ) secured in position, and appropriately braced, at least one clamp device  50  in accordance with the invention is secured at one end thereof to the truss  32  adjacent the top thereof as shown in  FIG. 1 . Preferably at least one second like clamp device  50  (not shown) would be installed on the other side of peak  52  of truss  32 . Clamp device  50  is more particularly shown in  FIGS. 2-5 . 
   In  FIG. 2 , clamp device  50  is shown to include an adjustable, first clamp section  52  and a second, pivotal clamp section  54 . First clamp section  52  is basically a known form of a bar clamp device and has fixed jaw  56  and slidable jaw  58  with fixed handle portion  60  and squeezeable handle portion  62 . First clamp section  52 , as a bar clamp, operates in known fashion and release button  64  allows the jaws  56 ,  58  to separate, the jaw  58  sliding on bar  64  relative to jaw  56 . In use, first clamp section  52  is secured to truss  32 . 
   As further shown in  FIG. 2 , second clamp section  54  includes bar  70  and has L-shaped clamp member  72  welded or otherwise secured to bar  70 . L-shaped clamp member  72  comprises leg portion  74  and arm portion  76 . Spaced from leg portion  74  is rotatable clamp member  78  which is pivotally secured to arm portion  76  at pivot  80 . Rotatable clamp member  78  has opposite side surfaces  82 ,  84  and has pins or posts  86  and  88  extending from opposite side surfaces  82  and  84  respectively. Pin or post  86  on the far side surface  82 , as seen in  FIG. 2  acts as a stop means relative to arm portion  76  to limit the rotation of rotatable clamp member  78  in the counterclockwise direction as shown in  FIG. 2 . Pin or post  88  on the near side surface  84  extends outwardly so as to enable securement of one end of coil spring  92 . The other end of coil spring  92  is secured to another pin or post  96  secured to L-shaped clamp member  72 . 
   Pivotal clamp member  78  is configured to have a straight section  100  and a bulbous section  102 . 
   It will be appreciated from reviewing  FIGS. 2-4  that as truss  34  shown in dotted lines is swung into place in the direction of arrow  104 , its upper end  106  contacting bulbous section  102  of clamp member  78 . Continued forced movement of upper truss end  106  in the direction of the arrow  104  forces and causes clamp member  78  to rotate in a clockwise direction as seen in  FIG. 3 . Continued movement of truss  34  causes truss side  108  to contact clamp leg portion  74  at which time rotatable clamp member  78  has rotated so that flat edge  110  contacts the side of upper end  106  of truss  34 . During the rotation of rotatable clamp member  78 , coil spring  92  has moved over pivot  80 , that is, an “over center” action is provided by the configuration of the spring  92  and pivot  80  when member  78  is rotated. Rotatable clamp member edge  110  is thus caused to contact and hold the upper portion  106  of truss  34  tightly against fixed clamp member  72  under the bias of spring  92 . In summary, the rotatable clamp member  78  with the over center spring/pivot configuration, is caused to trip from a first non-clamping position to a second clamping position. 
   Clamp sections  52  and  54  are adjustably associated via block  120  which is secured to bar  70 , such as by welding. Block  120  has means provided in the illustrated embodiment, as best seen in  FIG. 5 , to secure bar  64  thereto, such means comprising a groove  122  in block  120  and cover plate  124  secured by fastening screws  126 .  FIG. 5  is a perspective view from the bottom of the clamp section  54  as seen in  FIG. 2 . This construction allows relative movement between the bars  64 ,  70  when screws  126  are loosened. Accordingly, the spacing between the first clamp section  52  and the second clamp section  54  can be adjusted to match the desired spacing between adjacent trusses. 
   When truss  34  is clamped in place, it is then secured by normal bracing (not shown) and clamp device  50  can be removed by releasing clamp section  52  from truss  32  and pulling both sections  52  and  54  upwardly from trusses  32  and  34  respectfully. Clamp device  50  is then reused for the next truss to be swung into place (not shown), clamp section  52  being then clamped to the just installed truss  34 . 
   As shown in dotted lines in  FIGS. 2 ,  3  and  4 , and full lines in  FIG. 5 , pivoted clamp portion has block  130  which enlarges the contact area between the edge  110  of rotatable clamp member  78  and the side of truss upper end  106 . A similar block  132  ( FIG. 5 ) can be made part of member  74  for similar reasons. 
   It will be appreciated that any number of clamp devices or apparatuses  50  can be used and reused in erecting a truss assembly. If final securement of a truss by normal means is not performed until several trusses have been located in place, then the clamp device  50  can be left in place until final securement is made. The spring force of spring  92  is made such as to firmly hold and temporarily secure each truss swung into place. Nevertheless, the clamp section  54  may be easily pulled from a truss  34  swung into place and otherwise normally secured. 
   Turning to  FIGS. 6 to 9 , a further preferred embodiment of the invention and more particularly, pivotal clamp section  54   a  is illustrated. Parts which are essentially the same to the embodiment of  FIGS. 2 to 5  have the same reference numerals and other parts or elements which have been modified, but are similar, are designated with an “a”. 
   As seen in  FIGS. 8 and 9 , arm portion  76   a  of L-shaped clamp member  72   a  is sized and configured to have groove  122   a  therethrough, groove  122   a  configured to accept bar  64  of clamp section  52 . Arm portion  76   a  has cover plate  124   a  which is detachable and releasably secured to arm member  76   a  by screw fasteners  126   a , or the like. The construction incorporates the adjustability between clamp sections  52  and  54   a  into the arm portion  76   a  of the L-shaped clamp member  74 . 
   Turning to  FIGS. 6 and 7 , the main difference between this embodiment and that of  FIGS. 2 to 5  is in the enlarged bulbous portion  102   a  which is generally semi-circular. Further, there is a lock mechanism  140  which locks the rotatable clamp member  78   a  from accidentally opening while other forms of securement of the truss are being effected. Lock mechanism  140  comprises block or housing  142  which is secured to and effectively part of arm portion  76   a . Block  142  has a through bore  144  within which pin  146  reciprocates. Pin  146  is secured to spring arm  148  and spring arm  148  is secured at one end  150  to block  142  by fastener means  152 . The other end  154  of spring arm  148  extends beyond the block  142  and can be manually activated or manipulated. 
   As will be appreciated from  FIGS. 6 and 8 , when pivotal section  54   a  is in position to be tripped by a truss  34 , the bulbous portion  102   a  covers and maintains pin in a retracted position ( FIG. 8 ) whereas when truss  34  has tripped rotatable clamp member  78   a , the bias of spring arm  148  forces pin  146  to extend outwardly so that pin  146 , in contacting part  158  of bulbous portion  102   a , prevents rotatable clamp member  78   a  from rotating back in a counterclockwise direction as seen in  FIG. 7 . 
   Arm spring end  154  can be manually manipulated (downwardly as seen in  FIGS. 8 and 9 ) to retract pin  142  and allow the rotatable clamp member to be returned to the position shown in  FIG. 6 . 
   The clamp device  50  has clamp sections  52  and  54  ( 54   a ) spacially adjustable relative to each other to enable the distance between them to be selected. Although two or any number of clamp devices  50  can be used in assembling trusses of a building, additional support during assembly can be provided and, the invention further comprehends a clamp device  50  wherein the selected space between clamp sections  52  and  54  ( 54   a ) is twice the desired spacing between adjacent trusses. In this embodiment there is preferably and adjustable auxiliary clamp element  160  shown in  FIG. 10 . 
     FIG. 10  is a cross-sectional view of the bar  64  of clamp section  52  and of a truss  34 . Auxiliary clamp element  160  has a U-shaped portion  162  with thumb screw  164  so that device  160  can be slidably fixed or secured to bar  64  at a desired location. Auxiliary clamp element  160  has extension  166  with a prong or projection  168 . In use, clamp section  52  with an extended bar  64  can be secured to fixed truss  30  for example, and auxiliary clamp element  160  adjusted so that projection  168  is aligned with fixed truss  32  and clamp section  54  ( 54   a ) is in place to secure truss  36  when it is swung up into position. Prong or projection  168  is tapped by a hammer into the upper frame member of the intermediate truss which further steadies the clamp device  50  when the next adjacent truss  36  is swung into position. The added stability to the clamp device  50  with the increased span and auxiliary clamp element  160  is significant. Such an extended version of the clamp device is shown in dotted lines in  FIG. 1  as  50 ′ although it would normally in use be higher up and closer to the ridge section of the truss. 
   Although applicants have described preferred embodiments of the invention, variations and modifications will be apparent to those skilled in the art and applicants do not limit the scope of the invention solely to such preferred embodiments, but include variations and modifications which fall within the scope of the appended claims.