Rolling Truss Joint Connector Plates

Abstract

Toothed connector plates are embedded in opposite faces of wood truss components in a single pass through a pair of rolls while the truss components are held together horizontally in a jig having sufficient vertical flexibility to conform to the curvature of an elevated area of the lower roll at the nip of the rolls.

Parent Case Text

RELATED APPLICATION

This application is a continuation-in-part of my prior copending application, Ser. No. 332,347, filed Feb. 14, 1973 and now abandoned.

Description

BACKGROUND OF THE INVENTION

In the fabrication of trusses having wood components, metal plates having a plurality of closely spaced pointed teeth are embedded into opposite faces of the wood components to make strong tight joints and to reinforce the wood components. It is necessary to press the teeth until they are fully embedded into the wood in order to obtain maximum holding power of the teeth in the wood and to utilize fully the strength of the metal plate, and this requires a substantial amount of pressure to be applied to the plate. Hammer presses have been used successfully to fully embed the teeth, but from a production standpoint too much time has been involved in having each truss joint static during the pressing operation.

It has been proposed to support the assembled truss components, with connector plates top and bottom of the joints, horizontally in stationary position and pass a traveling roller over the top thereof to progressively embed the teeth at the various joints, but this operation not only requires a reaction pressure pad under each joint and tracks for the traveling roller but also the teeth of the plates on the undersides of the joints are not fully embedded, apparently because the pressure of the roller is not sufficiently concentrated on that side, so that the assembly must also be passed through a pair of pinch rolls to fully embed the teeth of the bottom plates.

It has also been attempted to assemble the truss components in a jig on a substantially rigid flat horizontal bed plate, with connector plates located top and bottom of the joints, and then pass the assembly including the bed plate through a pair of pinch rolls to progressively embed the teeth at the joints, but again in this operation the bottom teeth are not fully embedded and at least one additional pass through the rolls is necessary to complete the embedment. The flat rigid bed plate has been used to hold the truss assemblies in flat condition until they are joined by the connector plates but apparently the pressure of the rolls in passing through the bed plate is not transmitted to the bottom connector plates in a sufficientlly concentrated area to fully embed the teeth.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved method and apparatus for rolling the top and bottom connector plates at the joints of wood trusses to fully embed the teeth thereof in a single pass through a pair of rolls.

Another object is to provide an improved method for rolling top and bottom connector plates on wood truss components by holding the components and plates horizontally in assembled position on a flexible bed pan while permitting limited vertical flexing of the pan during passage through a pair of rolls positioned relative to the pan so as to progressively conform the pan to the curved area at the nip of the lower roll.

Another object is to provide a simple and improved flexible jig pan for holding the assembled truss components and top and bottom connector plates in horizontal position and for conforming progressively to the curved nip area of the lower roll while passing the assembly through a pair of rolls to fully embed the teeth of the connector plates.

A further object is to provide an improved jig for holding the assembled truss components and top and bottom connector plates in horizontal position with sufficient vertical flexibility to conform to the curvature of the nip area of the lower roll of a pair of rolls while passing them over and under the jig to fully embed the teeth, and with sufficient lateral adjustability to apply camber to the truss.

Another object is to provide an improved jig supported on a thin flexible pan for holding assembled truss components and top and bottom toothed plates normally in horizontal position, and adapted to conform progressively to the curvature of the nip area of the lower roll of a pair of rolls while passing therethrough.

A still further object is to provide an improved jig supported on a thin flexible pan for holding assembled truss components and top and bottom toothed plates as the assembly is passed through a pair of rolls having an elevated nip area, said flexible pan being adapted to support an additional jig for holding side-by-side truss components having toothed plates thereon which are simultaneously embedded during the same pass through the rolls.

Still another object is to provide improved rocker means for supporting a flat jig bed in horizontal position, said rocker supporting means allowing a pair of vertically spaced rolls to pass over and under the bed with truss components and connector plates supported thereon, so as to progressively embed the connector plate teeth into the truss components.

These and other objects are accomplished by the novel and improved method and apparatus, preferred embodiments of which are shown in the accompanying drawings and described in detail in the following specification. Various modifications and changes in details of construction are comprehended within the scope of the appended claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 and 1A taken together are a plan view of one embodiment of an improved flexible jig according to the present invention, showing truss components supported thereon.

FIG. 2 is an enlargedd partial elevation on line 2--2 of FIG. 1.

FIG. 3 is an enlarged sectional view on line 3--3 of FIG. 1, showing two wood chords held in the upper part of the jig.

FIG. 4 is a plan view on line 4--4 of FIG. 3.

FIG. 5 is an enlarged partial sectional views as on line 5--5 of FIG. 1 showing the truss components held in assembled relation prior to passage between the pinch rolls.

FIG. 6 is a partial perspective of one of the vertical struts of the truss.

FIG. 7 is an enlarged partial sectional view on line 7--7 of FIG. 1.

FIG. 8 is a plan sectional view on line 8--8 of FIG. 7.

FIG. 9 is an enlarged partial sectional view on line 9--9 of FIG. 1.

FIG. 10 is a plan view thereof.

FIG. 11 is a plan view of the wood chords in the upper part of the jig after plates have been embedded in their upper surfaces.

FIG. 12 is an enlarged partial sectional view on line 12--12 of FIG. 11 at a splice joint in either chord, showing three overlapping plates.

FIG. 13 is an enlarged view on line 13--13 of FIG. 11. showing two overlapping plates.

FIG. 14 is a plan view of a finished truss fabricated in the lower part of the jig of FIGS. 1 and 1A.

FIG. 15 is an enlarged cross-sectional view of the jig of FIGS. 1 and 1A with the truss components held therein during passage between the pinch rolls.

FIG. 16 is a partial cross section on line 16--16 of FIG. 15.

FIGS. 17 and 17A taken together are a plan view of a modified flexible jig and traveling gantry roll stand according to the present invention, showing the truss components in phantom lines.

FIG. 18 is an enlarged partial section on line 18--18 of FIG. 17A

FIG. 19 is an enlarged partial plan view taken at the area indicated in FIG. 17A.

FIG. 20 is a sectional view on line 20--20 of FIG. 19.

FIG. 21 is an enlarged partial sectional view on line 21--21 of FIG. 17A.

FIG. 22 is a partial side elevation of the jig and gantry roll stand shown in FIG. 17A.

FIG. 23 is an enlarged partial plan sectional view on line 23--23 of FIG. 22.

FIG. 24 is an enlarged partial longitudinal sectional view through the jig and gantry roll stand of FIG. 17A, showing somewhat schematically how the rolls embed the teeth of the top and bottom connector plates in the wood chords as the rolls pass thereover.

FIG. 25 is a reduced cross section on line 25--25 of FIG. 24.

FIG. 26 is an enlarged partial sectional view similar to FIG. 24.

FIG. 27 is an enlarged cross-sectional view on line 27--27 of FIG. 22, showing mechanism for lifting completed trusses above the bed of the jig.

FIG. 28 is an enlarged partial elevation on line 28--28 of FIG. 27.

DESCRIPTION OF ONE PREFERRED EMBODIMENT

The improved jig in FIGS. 1 and 1A has a lower portion for holding an assembled truss in position for passing through a pair of pinch rolls, and an upper portion for holding side-by-side two additional truss components having toothed plates to be embedded thereon simultaneously during the same pass through the rolls, as shown in FIG. 15, these two additional components being thus processed for use in a subsequent truss assembly.

However, because the two additional components, as positioned in the upper portion of the jig occupy less vertical space than the truss assembly in the lower portion, a separate collar is journaled on the upper roll shaft to compensate. It is apparent that the upper and lower portions of the jig can be separated and passed through the same or a separate pair of pinch rolls at the same or different times.

In FIGS. 1 and 1A the jig is shown as embodying a supporting bed pan 16 having three flexible sheets or sections 16A, 16B and 16C joined in edge abutting relation to form an elongated flexible pan supported on a roller conveyor 15 or the like (FIG. 16) and adapted to accommodate a truss assembly such as shown in position in FIGS. 1 and 1A and in finished form in FIG. 14. The abutting sheets may be detachably joined in abutting relation in the manner shown in FIGS. 9 and 10 in which straps 17 span the joint and fit over tubular stubs 18 welded around their inside edges, one to each adjoining sheet. The sheets 16A, 16B and 16C are preferably spring steel of the order of one-eighth inch thick.

Along one marginal portion of the bed pan, which is the lower portion as shown in FIGS. 1 and 1A, are supported two longitudinal elongated truss holding members indicated generally at 20 and 21 and comprising parts of the improved jig. The inner member 20 is supported in fixed position on the bed pan and the outer member 21 is supported movably thereon.

The truss holding members 20 and 21 each preferably comprise a flexible elongated ribbon 22 of spring steel about 1/8 inch thick which lies flat on the bed pan and extends longitudinally thereof. Each of the ribbons 22 has a longitudinal series of spaced-apart angles 23 having their horizontal legs secured to the top surface thereof, as by rivets 24. The vertical legs of the angles on members 20 and 21 are opposed, that is, the vertical legs on member 20 face the vertical legs on member 21, so as to abut the upper and lower chords of a truss assembly held between the members. As shown, the vertical legs of angles 23 are of substantially less height than chords 36 and 37.

As shown in FIGS. 7 and 8, abutting lengths of the ribbons 22 may be connected at their splice joints by straps 25 having apertures which fit over tubular stubs 26 welded around their inner edges to the horizontal legs of adjacent angles 23.

As shown in FIG. 2, the member 20 may be fixedly mounted on the bed pan 16 by providing apertures at longitudinal intervals in the ribbon 22 thereof which fit over a row of tubular stubs 28 welded around their inner edges to the bed pan. Other rows of tubular stubs 28A and 28B may be welded to the bed pan to mount the member 20 at different spacings from member 21 for holding trusses of different heights therebetween.

Preferably, the rows of stubs 28, 28A and 28B are longitudinally aligned along a very gradual curve to produce a slight camber in the abutting chord of the truss and cause it to be pre-stressed when formed. Means are provided to form the opposite chord of the truss with a matching camber when the truss components are held in assembled relation between the members 20 and 21.

The truss holding member 21 is movably supported on the pan 16, and eccentric clamping devices are rotatably eccentrically mounted on the pan at longitudinal intervals along member 21 and aligned so as to produce a matching camber in the adjacent truss chord. Each clamp is mounted on the pan adjacent to an angle 23 for abutting the vertical leg thereof. As shown in FIG. 5, the clamps each comprise a circular block 30 eccentrically rotatably mounted on a bar 31 which overlies the horizontal leg of an angle 23 and is mounted on a block 32 secured to the pan. The circular block 30 abuts the vertical leg of the angle 23 and has a bar handle 33 secured thereto.

The truss shown in finished form in FIG. 14 has an upper wood chord 36 and a lower wood chord 37 with vertical metal struts 38 and inclined metal struts 39 extending at intervals between the chords. The metal struts 38 and 39 are secured to the wood chords by toothed metal plates. This type of truss construction is shown in detail in my prior Pat. No. 3,416,283, except that in the truss shown in said patent the metal struts are all disposed diagonally or inclined with respect to the chords. As best shown in FIG. 6, the struts 38 and 39 herein have flat load transfer flanges 40 at each end and channel-shaped bars between and connected to the flanges. The flanges have a plurality of apertures 41 which intermesh with the teeth 42 of overlying toothed connector plates 43 when the teeth are embedded into the wood chords.

As indicated, alternate vertical struts and alternate inclined struts are positioned on opposite sides of the truss, although struts at both ends may be placed on both sides. Thus, in assembling the truss components between the truss holding members 20 and 21, it is necessary first to place on the bed pan the alternate struts with the toothed connector plates having their teeth extending upwardly in meshing relation with the apertures of the transfer flanges, then to place the wood chords 36 and 37 over the transfer flanges, and then to place on top of the chords the other struts with toothed connector plates having their teeth extending downwardly in meshing relation with the apertures of the top transfer flanges. Such relationship of chords and plates is seen in FIGS. 1, 1A and 14.

It will also be seen in FIGS. 5, 6 and 15 that the vertical struts 28 have a large tooth 46 at each end of the channel portion extending inward in the direction of the channel legs for abutting the inner faces of the chords 36 and 37. These teeth 46 temporarily hold the chords in proper spaced-apart relation when the eccentric clamps 30 are actuated to press the lower chord 37 toward the upper chord 36 to camber the lower chord in parallelism with the upper chord and hold the truss components in proper assembled relationship.

with the truss components in such relation, the pan, together with the holding member 22 and the assembly clamped therein is moved along its supporting conveyor so as to pass through a pair of pressure or pinch rolls 49 and 50 to press the toothed plates 43 into opposite sides of the wood chords 36 and 37. As indicated in FIG. 16, the upper surface of lower roll 50 is elevated above the plane of the pan 16 as supported on either side of the roll and the distance between rolls 49 and 50 at the nip is such as to press the teeth 42 fully into the wood chords 22. Thus the thin flexible pan 16 and the holding members thereon are forced to bow or ripple slightly to conform to the curvature of the nip area of the lower roll as the flexible jig passes through the rolls, and the full pressure of the rolls is concentrated on the plates 43 at the tangents of both rolls at the nip, thereby fully embedding the teeth 42 of the bottom plates 43 in the bottom of the chords as well as the teeth 42 of the top plates 43 in the top of the chords. Obviously, the same result would be obtained if the pan and jig members were held stationary and the rolls passed thereover, in which case the pan would be supported on movable supporting legs which would move out of the way as the rolls momentarily support the pan.

It will be seen in FIGS. 5 and 15 that the inner faces of the wood chord members 36 and 37 have two overlapping metal plates 52 and 53 thereon. These are reinforcing metal strips applied to the chords prior to assembling them between the holding members 20 and 21. The strips 52 and 53 may be applied to two chords on a separate bed pan or, as shown in FIGS. 1, 1A and 15, the strips may be applied to two chords 36' and 37' held in position on the same pan 16 during the same pass through the rolls which completes the truss assembly, the chords 36' and 37' being thus prepared for insertion into the next successive truss assembly.

As shown, the two chord members 36' and 37' are placed flatwise side-by-side with narrow faces in abutment between two longitudinal holding members 20' and 21' extending along the upper marginal portion of the pan 16. The outer or upper holding member 20' is supported in fixed linear position on the pan and the inner member 21' is movably supported on the pan. The members 20' and 21' each comprise a flexible elongated ribbon 22' of spring steel about one-eight inch thick and having a series of spaced-apart angles 23' secured thereto, the vertical legs of the angles being of substantially less height than the height of the chords lying flatwise therebetween. Eccentric clamps 30' are mounted on the pan adjacent to the holding member 21' for moving it toward member 20' to clamp chords 36' and 37' in position.

As seen in FIGS. 3 and 4, the strips 53 have a plurality of teeth 42' which mesh with a plurality of apertures in strips 52 and the meshed strips are positioned on the top surfaces of the chords 36' and 37' prior to passing through the rolls for fully embedding the teeth into the chords. In view of the difference in height between the chords 36' and 37' positioned flatwise and the chords 36 and 37 positioned edgewise in the assembly, a collar 49A of correspondingly larger diameter is journaled on the shaft of roll 49 to simultaneously roll the strips 52 and 53 to fully embed teeth 42' into chords 36' and 37'.

If the strips 52 and 53 are applied to the chord members 36' and 37' between holding members 20' and 21' supported on a separate pan, then a platform member may be used on the pan to increase the overall height of the assembly to equal that of the truss assembly, and the need for collar 49A is eliminated. In such case the plane of the separate pan as supported beyond the rolls could be at the same level as the upper surface of the lower roll, as it is not necessary to bow the pan because the only teeth being embedded are at the top surfaces of chords 36' and 37'.

As shown in FIG. 13, the toothed strip 53 may extend beyond the ends of the perforate strip 52, and as shown in FIG. 12, a shorter perforate strip 54 may be placed under perforate strip 52 at splice joints in the chords.

DESCRIPTION OF ANOTHER PREFERRED EMBODIMENT

In the embodiment of FIGS. 17 - 28, the jig is shown in FIGS, 17, 17A as embodying a bed pan indicated generally at 116 supporting the assembled components of two trusses of different heights of the type depicted in FIG. 14, shown in phantom in FIGS. 17, 17A in side-by-side relation. Obviously, other truss chords and components for assembling other types of trusses can be similarly held and supported.

The bed pan 116 comprises a longitudinal series of sheet panels 116A, 116B, 116C, 116D, 116E and 116F supported at their transverse edges. The panels are preferably of flexible plastic material such as polyurethane, approximately three-eighth inch thick. As shown in FIG. 18, the transverse edges of the panels are received and supported in lightweight channels 117, preferably of 18 gauge steel, the webs of the channels being secured to transverse bars 118 by studs 118'. At the adjacent edges of the panels two bars 118 spaced apart to form slots about two inches wide are used, the transverse edges of adjacent panels being secured one to each bar. The purpose of the slots is to accommodate mechanism for lifting completed trusses, as will be later described.

Longitudinal metal ribbons 119a and 119B connect the panels 116A, 116B, 116C, 116D, 116E and 116F together along their marginal edges. The ribbons are secured to the transverse bars 118 by screw studs 120. Between the panels 116C and 116D is a space for adjusting the length overall of the jig to different lengths of trusses. Adjustable connector straps 121 having a series of holes therein are bolted to the ribbons 119A and 119B in adjusted positions. At the ends of the panels 116A and 116F rigid rectangular frames are provided having upright corner posts 122 (FIG. 22) connected by a transverse top angle 123, and side straps 124 are connected to the ribbons 119A and 119B by adjustable straps 125 (FIG. 23).

Between the end frames the panels of the bed pan 116 are supported by longitudinally aligned lateral rows of rocker supports shown in FIGS. 22, 24 and 25. Each rocker support has a U-shaped rod 128 pivotally supported at its medial portion on a vertical base plate 129 by means of a yoke 130. There are preferably three rocker supports in each lateral row and transverse angles 131 connect their aligned upper ends. Rollers 132 are journaled in bracket plates 133 welded in the angles and these rollers are adapted alternately to engaged and support the panels 116 at the same level as their transverse edges are supported in the angles 117 when the rods 128 are rocked from the full line position of FIGS. 22 and 24 to the phaantom position at the left portion of FIG. 24.

The rocker supports are located so that the rollers 132 engage the panels 116A - 116F substantially medially of their transverse edges. In other words, referring to FIGS. 17, 17A, the rollers 132 engage each of the panels substantially midway between the channels 117 in which their transverse edges are supported.

As shown in FIGS. 17A, 22 and 23, a gantry roll stand indicated generally at 135 is rollably mounted on tracks 136 extending along opposite sides of the bed pan 116 for stradling the bed pan. The gantry stand embodies laterally spaced A-frames 137 supported on rollers 138 rolling on the tracks 136. Upper and lower rolls 139 and 140 are journaled in the frames 137 in vertically spaced relation to pass over and under the bed pan 116 with the upper roll engaging the upper surfaces of truss components supported thereon and the lower roll engaging the panels of the bed pan, as best depicted in FIGS. 24 and 25.

A drive motor 142 supported on top of one of the A-frames 137 drives the upper roll 139 by means of a chain 143 engaging a sprocket 144 on one end of roll shaft 139', and a sprocket 145 on the other end of the shaft 139' is operatively engaged with a sprocket (not shown) on the other roll shaft 140'. The specific construction of the gantry roll stand 135 forms no part of the present invention.

The truss holding jig members for holding the truss components in assembled position on the bed pan 116 comprise longitudinal angles on opposite sides of the two trusses of different lateral dimensions shown in FIGS. 17, 17A. Longitudinal angles 150 abut the other sides of the upper and lower trusses indicated generally at A and B, respectively, and longitudinal angles 151 are positioned adjacent to the inner sides of said trusses. Referring to FIGS. 19 and 20, the angles 150 are movably supported on the bed pan 116, and are held in abutment with the adjacent chords 37 of the trusses by clamps 152 mounted on brackets 153 attached at longitudinal intervals to the ribbons 119A and 119B by studs 154. The clamps 152 may have fluid actuated piston rods 155 connected to the angles 150.

The angles 151 extending along the inner sides of the trusses A and B, as best shown in FIG. 21, are supported in fixed positions on the bed pan 116 by studs 156, and are spaced from the adjacent cords of the trusses. Longitudinal vertically disposed abutment plates 157 abut the adjacent truss chords and are adjustably connected to the angles 151 by screws 158, so that a slight camber can be produced and maintained in the adjacent chords. As shown, the height of the vertical legs of the angles 150 and 151 and the height of the abutment plates 157 is less than the height of the truss chords so they are not contacted by the upper roll passing over the truss components. by establishing this camber in the inner chords of the trusses and then applying the clamps 152 to the outer chords the entire trusses will be camber accordingly throughout their lengths. As shown, vertical rows of studs 156 are provided to fix the angles 151 in different positions to accommodate trusses of various lateral dimensions.

In the operation of the embodiment of FIGS. 17 - 28, with the components for the trusses A and B clamped in position by the truss holding jig members, and the toothed connector plates positioned top and bottom of the truss chords, in the same manner as described herein in connection with the embodiment of FIGS. 1 - 16, the gantry roll stand is moved from right to left as viewed in FIGS. 17, 17A. The vertical spacing of the rolls 139 and 140 is such that the upper roll 139 will embed the teeth of the upper connector plates 43 in the upper surfaces of chords 36 and 37, and the lower roll 140 will progressively engage the undersurfaces of the panels comprising the bed pan 116 to embed the teeth of the lower connector plates 43 in the lower surfaces of chords 36 and 37, as indicated in FIGS. 24 and 26.

The upper surface or nip of the lower roll is positioned so that it is tangent to the plane of the undersurfaces of the panesl 116A - 116F at their transverse edges, which would be the plane of the undersurface of the pan 116 if it were maintained horizontal throughout. However, there is a certain amount of sag in the flexible panels between their transverse edges and the rollers 132 of the rocker supports, and this sag produces an undulation or ripple in the panels as the roll 140 passes thereunder as depicted in FIG. 24, causing a slight progressive curving of the panels to conform to the upper surface at the bight of the roll and resulting in a concentration of the roll pressure to fully embed the teeth of the lower connector plates into the wood chords.

As the rolls move longitudinally over and under the jig the lower roll progressively contacts the upper rollers 132 of the rocker supports and rocks or rotates them about their pivots to the reverse positions as indicated in phantom lines in FIG. 24. After one pass from right to left, the gantry is stopped at the left end of the jig and the completed trusses are removed. New truss components are then assembled on the jig and clamped in position, whereupon the gantry is moved thereover from left to right to embed the teeth of the upper and lower connector plates, and the lower roll progressively rocks the rocker supports back to the full line position shown in FIGS. 22 and 24.

In the alternate positions of the rocker supports wherein one or the other sets of rollers 132 at opposite ends of the arms 128 engages and supports the bed pan 116, it will be seen by reference to FIG. 24 that the rollrs 132 do not quite reach over center position with respect to the pivot centers of the arms on the brackets 129. This insures that the arms are easily rocked by contact with the moving lower roll 140 of the gantry. However, in either alternate position of the rocker supports the lower ends of the arms abut the floor or supporting surface for the jig, and graivty maintains the arms in that position. The aggregate gravitational force of all the arms in either position is sufficient to support the weight of the bed panels between the angles 117 supporting their transverse edges.

The rocker supporting mechanism herein disclosed can be used for supporting a rigid bed pan in combination with a gantry roll stand having upper and lower rolls so that reaction pressure pads would not be required under each joint of the truss as in the case of a single gantry roll passing over trusses supported on a rigid jig. However, in such case the ripple effect would not be obtained to insure concentration of the pressure of the lower roll with consequent full embedment of the teeth of the bottom plates, and a second pass of the gantry over the supported trusses in inverted position would be required.

The mechanism shown in FIGS. 27 and 28 for lifting completed trusses above the bed of the jig to facilitate removal of the trusses comprises a series of scissors lever arrangements each powered by a fluid cylinder 160, one lever arrangement for each two inches slot between the bars 118 supporting the transverse edges of adjacent panels 116 (see FIG. 18). Each scissors arrangement preferably has aligned upwardly projecting rollers 161 for projecting upwardly through the 2 inches slots and lifting the completed trusses when the scissors levers are extended. FIG. 27 shows the retracted position of the levers in full lines and the extended position in phantom.

Each scissors mechanism preferably comprises two pairs of crossed levers 162A and 162B pivoted together at their medial portions, their lower ends carrying rollers 163 journaled on cross shafts 164 and their upper ends carrying rollers 165 journaled on cross shafts 166. The lower rollers 163 are rollable in interfacing channels 167 mounted on a base plate 168, and the upper rollers 165 are rollable in interfacing channels 169 supporting a top plate from the medial portion of which the rollers 161 and the mounting brackets 161' project upwardly. One of the lower cross shafts 164 has the piston rod 170 of fluid cylinder 160 swiveled thereto, the other end of the cylinder being pivoted on a bracket 171 mounted on base plate 168. Hence, retraction of the piston rod 170 will extend the scissors levers 162A and 162B to the phantom position and project the rollers 161 upwardly through the slots in the bed pan.

It will be apparent that there have been disclosed herein improved methods and apparatus for rolling top and bottom toothed connector plates to fully embed the teeth into wood truss components in a single pass through a pair of rolls by using a vertically flexible jig bed which momentarily conforms to the upper nip area of the lower roll as the jig passes through the traveling rolls.

Claims

I claim: pg,20

1. The method of fully embedding toothed connector plates in opposite faces of assembled truss components including wood components, comprising clamping the truss components in horizontal assembled position on a vertically flexible horizontal jig bed with the toothed plates located on the top and bottom faces of said wood components, positioning a pair of vertically spaced pressure rolls above and below said jig bed having the nip of the rolls positioned relative to the plane of the jig bed to conform the bed progressively during passage between the rolls to the curved area at the nip of the lower roll, and causing relative movement between the jig bed and the rolls, thereby embedding the top and bottom toothed plates into the wood components.

2. The method of fully embedding toothed connector plates as described in claim 1, in which the assembled components include laterally spaced longitudinal wood chord members supported on the flexible jig bed and pressure is applied laterally to the chord members to hold all the components in assembled position.

3. The method of fully embedding toothed connector plates as described in claim 2, in which pressure is applied laterally to the chord members to produce a camber therein and to hold all the components in assembled position.

4. The method of claim 1 in which the nip area of the lower roll is elevated above the plane of the jig bed.

5. Apparatus for embedding toothed connector plates in opposite faces of assembled truss components including wood truss components, comprising a flexible jig bed, longitudinally spaced means supporting said bed in horizontal position, means clamping said truss components in assembled position on said bed, and a pair of vertically spaced horizontal pressure rolls adapted to press the teeth of the connector plates fully into the top and bottom faces of said wood components, said flexible bed adapted between supports to conform to the upper curved area of the lower roll, the nip of said rolls being positioned relative to the horizontal plane of said bed to conform said bed progressively to the upper curved area of the lower roll during relative movement between the bed and the rolls such as to cause the bed and the assembly thereon to pass through the nip of the rolls.

6. Apparatus for embedding toothed connector plates as described in claim 5, in which the assembled components are clamped laterally of the direction of movement between longitudinal vertically flexible members supported on said bed and are adapted to pass through the nip of the rolls with said bed and said assembly.

7. Apparatus for embedding toothed connector plates as described in claim 6, in which the assembled components include laterally spaced longitudinally chords abutted by said longitudinal members and means are mounted on said bed for applying lateral pressure to one of said longitudinal members.

8. Apparatus for embedding toothed connector plates as described in claim 7, in which one of said longitudinal members is mounted on said bed with a lateral camber, and means are mounted on said pan for applying lateral pressure to the other of said longitudinal members to produce a corresponding lateral camber therein.

9. Apparatus for embedding toothed connector plates as described in claim 7, in which a second pair of longitudinal chord members to be used for another assembly is supported laterally of said assembled components and in side-by-side abutting relation, and toothed plates located on the upper faces thereof for being fully embedded during passage between said rolls.

10. Apparatus for embedding toothed connector plates as described in claim 9, in which the second pair of longitudinal chord members is clamped between longitudinal vertically flexible members supported on a bed, and means are mounted on said bed for applying lateral pressure to one of said second longitudinal members.

11. Apparatus for embedding toothed connector plates as described in claim 10, in which the longitudinal members clamping the second pair of longitudinal chord members are supported on the same bed as the truss assembly and a collar is journaled on the upper roll of said pressure rolls for embedding the teeth of said toothed plates into said second pair of longitudinal chord members.

12. Apparatus for embedding toothed connector plates as described in claim 9, in which the second pair of longitudinal chord members is supported on the same bed as the truss assembly and a collar is journaled on the upper roll of said pressure rolls for embedding the teeth of said toothed plates into said second pair of longitudinal chord members.

13. Apparatus as described in claim 5, in which the nip area of the lower roll is elevated above the plane of the jig bed.

14. The method of embedding toothed connector plates in opposite faces of assembled truss components, comprising clamping the truss components in horizontal assembled position on a vertically flexible horizontal bed pan with the toothed plates located on the top and bottom faces of certain of said components, positioning a pair of vertically spaced pressure rolls over and under said pan with the lower roll contacting the under surface of said pan, passing said rolls over and under said pan and progressively supporting the pan only in advance of and behind said lower roll to allow said pan to ripple as it conforms progressively to the nip area of the lower roll.

15. Apparatus for embedding toothed connector plates in opposite faces of assembled truss components, comprising a flexible bed pan, longitudinally spaced means supporting the pan in horizontal position, means clamping said truss components in assembled position on said pan with the toothed connector plates contacting opposite faces of certain of said components, a pair of vertically spaced horizontal pressure rolls adapted to pass over and under said pan to embed said connector plates in said certain components, said flexible bed pan adapted between supports to conform to the upper curved area of the lower roll, said pan supporting means progressively alternately supporting said pan in advance of and behind said lower pressure roll to allow said pan to ripple as it conforms progressively to the curved upper area of the lower roll during passage of the rolls.

16. Apparatus as described in claim 15 in which said bed pan comprises a longitudinal series of flexible panels supported at their transverse edges on transverse bars.

17. Apparatus as described in claim 16, in which the transverse bars are spaced apart longitudinally to form slots.

18. Apparatus as described in claim 17, in which lifting means supported below said pan are adapted to extend through said slots to lift trusses supported on said pan.

19. Apparatus as described in claim 18, in which the lifting means comprises extensible and retractable scissors levers.