US3238867A - Jig assembly with automatic unlocking cam - Google Patents

Description

March 1965 J. c. JUREIT ETAL JIG ASSEMBLY WITH AUTOMATIC UNLOCKING CAM Filed April 29, 1965 2 Sheets-Sheet 1 INVENTORS.

JOHN C. JUREIT THEODORE J. BOWMAN A TTORNE Y5:

Mar h 8, 9 J. c. JUREIT ETAL JIG ASSEMBLY WITH AUTOMATIC UNLOCKING- CAM Filed April 29, 1963 2 Sheets-Sheet :3

INVENTOILSZ JOHN C JURE IT Ill:-

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BY THEODORE J. BOWMAN w wn A TTORNE Y3.

United States Patent 3,238,867 HQ ASSEMBLY WITH AUTOMATIC UNLDCKING CAM Iiohn C. Jureit and Theodore J. Bowman, Miami, Fla, assignors to Automated Building Components, Inc., Miami, Fla, a corporation of Florida Filed Apr. 29, 1963, Ser. No. 276,389 Claims. (Cl. 100214) This invention relates to a jig for use in assembling prefabricated wooden structural members and more particularly relates to an improved jig which is uniquely constructed to provide for rapid loading and unloading.

In recent years, the building trades have shown a marked trend toward prefabrication, particularly in the construction of relatively low-cost residential housing. Various portions of frame houses have been preassem'bled in this fashion, the most common prefabricated element probably being the monoplane roof truss. This prefabrication itself has undergone an evolution from hand-nailing and bolting of the roof of the roof truss to the vastly improved method of construction which was made possible by the advent of structural butt joints formed with unitary connector plates of the type described in United States Patent No. 2,877,520, issued March 17, 1959.

In practically all monoplane roof truss assemblages, even the earlier type utilizing hand-nailing, it has been desirable, if not necessary, to pro-assemble the wooden structural elements on some type of frame or jig which held the elements in the proper position for the application of the connector devices. Where connector plates of the type described in United States Patent No. 2,877- 520 were utilized it became feasible to form an entire truss in a single pressing operation by assembling the wooden truss elements in a jig with connector plates on both sides of the butt joints and then subjecting the assemblage to pressure in a suitable press. One such press is illustrated in United States patent application Serial No. 66,999, filed November 3, 1960, for Concrete Press, now Patent No. 3,079,607, dated March 5, 1963.

In copending application Serial No. 228,662, filed October 5, 1962, there is disclosed an improved universal "g which is capable of preforming a wide variety of different shapes and types of roof trusses with only minor resetting of the jig. In that construction, provision is made for locking the wooden truss members in position by means of quick-acting cams which permit relatively rapid loading and unloading of the jig.

According to the present invention it has now been found that the loading and unloading procedure involved with a jig of the type disclosed in application Serial No. 228,662, may be even further expedited and speed through the use of a unique semi-automatic cam device. That is to say, in the jig assembly of the present invention the wooden members are held in position by means of camming devices which must be manually operated in order to lock the wood in position. However, after that is done, the unlocking is no longer manual as was the case in the past, but is now automatically accomplished upon closure of the press which presses the connector plates into po sition.

It is accordingly a primary object of the present invention to provide an improved jig assembly for prefabricating wooden structures.

It is another object of the invention to provide an improved jig assembly for prefabricating wooden structures wherein the jig assembly includes a semi-automatic means for locking and unlocking the wooden members of the wooden structures in position.

It is another object of the invention to provide an improved jig assembly for prefabricating wooden structures including a means for locking the wooden members in 3,238,867 Patented Mar. 8, 1966 "ice position and then automatically unlocking the wooden members after the truss is formed.

It is another object of the invention to provide an improved device for locking lumber in butted fashion for the formation of a connector joint wherein the device is automatically unlocked after the joint is formed.

It is another object of the invention to provide an improved jig assembly for prefabricating wooden structures wherein the jig assembly is universal in nature to permit the manufacture of a large variety of different size and shape wooden structures on the same jig without major modification of the jig itself.

It is another object of the invention to provide a universal jig assembly of the foregoing type having semiautomatic means for locking the wooden members in position so as to facilitate rapid loading and unloading of the jig with a minimum of labor.

These and further objects and advantages of the invention will become more apparent upon reference to the following specification and claims and the appended drawings wherein:

FIGURE 1 is a plan view of a universal jig assembly constructed according to the invention showing wooden structural members clamped in place by means of the clamp of the invention preparatory to the formation of a gable type truss assembly;

FIGURE 2 is a plan view of a semi-automatic locking device showing the locked and unlocked positions relative to a wooden member forming a butt joint;

FIGURE 3 is a vertical section, partly in elevation, taken substantially along the line 33 of FIGURE 1, showing the locking device of FIGURE 2 mounted on a reaction pad in the jig assembly of FIGURE 1; and

FIGURE 4 is a vertical section of a portion of the locking device taken on the line 44 of FIGURE 2.

Referring to FIGURE 1 of the drawings, there is shown a universal jig assembly of the type described in copending application Serial No. 228,662. This jig assembly, which is illustrated generally at It comprises a jig pad or pallet 12 formed of a large heavy sheet of metal or of a thin sheet of metal suitably reinforced, or of any other suitable structural material upon which the elements of the jig may be mounted. For purposes of clarity, only the center and lefthand portion of the complete jig assembly are shown. It is to be realized, however, that the complete assembly consists of a righthand portion which is constructed substantially as a mirror image of the lefthand portion along the broken line 13.

Mounted at the center of the jig pad 12 and extending transversely and vertically thereacross is a stationary vertical peak guide bar 14 which carries a peak reaction pad 16 slidably mounted 'for movement thereon. Extending perpendicular to the peak guide 14 along the entire length of the jig pad 12 are a series of stationary guide bars generally indicated at 18. These guide "bars consist of a heel guide bar 20 which terminates at 22 where it abuts the 1/3 point guide bar 24 which extends to the center of the jig pad. A heel reaction pad 26 is slidably mounted on the heel guide bar 20 while a 1/ 3 point reaction pad 28 and a splice reaction pad 30 are mounted on the 1/ 3 point guide bar 24.

The stationary guide bars 14, 2t) and 24 are identical in construction and are illustrated in FIGURE 3 which represents a cross section through the splice guide bar 24 along the line 33 of FIGURE 1. Referring to FIG- URE 3, it will be seen that the guide bar 24 consists of an elongated metal strip having flanges 32 which give the strip a generally T-shaped cross section. The guide bar may be secured to the jig pad in any suitable manner, such as by bolting, welding or riveting.

The splice reaction pad 30 consists of a metal plate 34 secured to a backing plate 36 which may be formed of metal or a suitable composition hardboard such as Masonite. The plate 36 may be fastened to the plate 34 by bolting, welding or riveting and is of substantially the same thickness as the guide 'bar 24. The splice reaction pad is slidably secured to the guide bar 24 by a pair of metal strips 38 and 40 having flanges 42 and 44 which matingly engage the flanges 32 on the guide bar. The strips 38 and 40 are secured to the splice reaction pad 30 in any suitable manner, such as by means of countersunk Allen-headed screws passing from the upper surface of the plate 34 into the strips so that the screw heads are readily accessible from the top of the reaction pad. These screws may be tightened to lock the reaction pad in position on the guide bar or may be loosened to permit sliding .motion of the reaction pad relative to the guide bar.

Running along the centerline of the guide bar 24 is a channel in which there is mounted a tape 46 hearing suitable indicia, such as foot and inch markings. Referring to FIGURE 1, an elongated slot 48 is provided in the splice reaction pad 30 directly above the tape 46. A suitable pointer is provided adjacent the slot 48 so that the reaction pad may be accurately located at any predetermined position along the guide bar 24. Details of one suitable pointer construction are disclosed in copending application Serial No. 228,662.

The heel reaction pad 26 and the 1/3 point reaction pad 28 are provided with similar slots and pointers indicated generally at 50 and 52in FIGURE 1.

Referring to the cross section of the splice reaction pad shown in FIGURE 3, an elongated angle 54 having a base 56 and an upstanding flange 58 is afiixed to the splice reaction pad plate 34 by means of a pair of screws 60 having Allen heads. The width or height of the upstanding flange 58 must be greater than the length of the teeth in the connector plate to be used so that the lumber will abut the flange 58 when mounted on top of the teeth in order that one step pressing may be accomplished.

The upstanding flange 58 of the angle 54 is adapted to engage the chord 62 of a roof truss to resist locking pressure applied by a semi-automatic locking device illustrated generally at 64.

Referring to FIGURES 2, 3 and 4, the locking device 64 consists of a cylindrical barrel 66 having a pair of base plates 68 and 70 welded or otherwise secured to the bottom area as seen in FIGURE 3. Slidably mounted within the barrel 66 is a pressure plunger generally indicated at 72 and consisting of a tube 74 having an arcuate plate 76 welded thereto. Mount-ed in the other end of the barrel 66 is a sliding plunger block 78 having a vertical diametral bore 80 therein. Received within the diametral bore 80 is a locking plunger 82 which is biased upwardly by means of a plunger spring 84 in the bottom of the bore 80, the locking plunger abutting against the inside surface of the barrel in the position shown in FIGURE 4.

' Still referring to FIGURE 4, an aperture 86 of substantially the same diameter as the plunger 82 is formed in the upper surface of the barrel to the right of the position of the plunger shown in FIGURE 4. An elongated release spring 88 is fastened to the upper side of the barrel 66, as by welding at the point 90, and has at its other end a dimple 92 positioned immediately over the apertule 86.

Projecting from the left end of the barrel 66 in FIG- URES 2, 3 and 4 are a pair of arms 94 and 96 in which is mounted a pivot pin 98. The pivot pin 98 rotatably supports an eccentrically mounted circular cam 100 having an actuating handle 102 projecting from the periphery thereof. A plunger spring 104 is mounted within the tube 74 of the pressure plunger 72 and simultaneously urges the pressure plunger to the right in FIGURE 4 and the plunger block 78 to the left into engagement with the cam 100.

When the cam 100 is in the unlocked position shown in solid lines in FIGURES 2, 3 and 4 prior to loading the jig assembly, the plunger block 78 abuts the cam as 1s seen in FIGURE 4. If the cam is now rotated in a clockwis direction by moving its handle 102 to the broken line position shown in FIGURE 2, the plunger block 78 is moved to the right and pressure is applied to the pressure plunger 72 by means of the plunger spring 104. When the locking plunger 82 becomes aligned with the aperture 86 the plunger is forced into the aperture by the spring 34 thereby locking the plunger 'block in position. The cam 100 may then be returned to the unlocked position shown in full lines in FIGURES 2 and 3 and the plunger 82 will retain the plunger block in its rightmost position as shown in FIGURE 3.

It will be recognized that in this position, the pressure plunger 72 is applying pressure to the wooden member 62 to retain it in position against the upstanding flange 58 of the angle 54. If the release spring 88 is now depressed so that the dimple 92 enters the aperture 86 and forces the locking plunger 82 downwardly, the plunger block 78 is released and is forced to the left by the pressure plunger spring 104 to release the wooden member 62, as will presently be described in further detail.

The locking device 64 is held in position on the splice reaction pad 30 by means of a pair of clamps 106 and 108 which are fastened to the plate 34 by means of Allenheaded screws 110 and 112. Loosening of the screws 110 and 112 permits the locking device to be slidably moved along the axis of the pressure plunger to permit the locking devices and reaction pads to be used with lumber of different thicknesses.

Referring now to FIGURE 1, a pair of parallel vertical stationary guide bars 114 and 116 are disposed near the center and left end of the jig pad respectively and provide an adjustable mounting for a horizontal 1/ 4 point movable guide bar 118. The left end of the movable guide bar 118 is attached to a connector plate 120 by a pin 122 received in a slot 124 in the connector plate. The connector plate itself is slidably secured to the guide bar 116 by means of flanged strips of the same type illustrated in connection with the splice reaction pad 30 in FIGURE 3, and a slot 126 is provided in the connector plate 120 to view a tape 128 carried by the vertical stationary guide bar 116. The right end of the movable guide bar 118 is pivotably secured to a second connector plate 130 by a pin 132. The connector plate 130 is slidably mounted on the vertical guide bar 114 in the same manner as the plate 120 and is also provided with a viewing slot (not shown) for positioning the connector plate 130 relative to a tape 134 in the vertical guide bar 114.

The construction of the 1/4 point guide bar 118 with the slotted connection at the left end and the pivoted connection at the right end permits easy movement of the bar by one man. That is to say, the connector plates 120 and 130 may be separately moved without resulting in binding and without the necessity of one man at each connector plate.

A 1/4 point reaction pad 136 is slidably mounted on the movable 1/4 point guide bar 118 in the same manner that the splice reaction pad is aflixed to the 1/3 point guide bar as illustrated in FIG. 3. The l/ 4 point reaction pad 136 carries a lumber positioning pin 138 and a locking device 140 similar to the locking device 64 on the splice reaction pad. The 1/3 point reaction pad 28 mounted on the l/3 point guide bar 24 carries no cam but has a lumber positioning pin 142 mounted thereon. The heel reaction pad 26 and the 1/ 3 point reaction pad 28 are provided with angles 144 and 146 similar to the angle 54 on the splice reaction pad 30.

The heel reaction pad 26 is also provided with a locking device 148 while the peak reaction pad 16 is provided with a pair of locking devices 150 and 152. The peak reaction pad also contains a series of lumber positioning pins 154. The splice reaction pad 30 contains, in addition to the locking device 64, a second locking device 156.

The jig of this invention is intended for use in the manufacture of monoplane roof trusses joined with structural butt joints of the type described in US. Patent No. 2,877,520. These particular joints are formed from butted wooden members held together by unitary connector plates which serve as the sole stress transmitting elements between the butted wooden members. Two such plates are shown in cross section in FIGURE 3. As will he been, these plates consist of bases 153 and 160 from which are struck a series of slender elongated and naillike teeth 162 and 164 which serve the dual function of transmitting shear stress, while at the same time providing necessary withdrawal resistance to hold the plate in position on the wooden members.

In utilizing the jig of the invention, a series of plates of this type are spotted on the reaction pads on the jig pad with the teeth extending upwardly prior to setting the wooden members on the reaction pads. The wooden members are then disposed on top of the teeth of the plates, as on top of the teeth 164, and a second set of connector plates is then laid on top of the wooden members with the teeth directed downwardly so that a single pressing operation is effective to completely form the roof truss.

Referring to FIGURE 1, the jig is shown as being set up to produce a gable type truss consisting of bottom or tie chords 62 and 166, top chords 168 and 170, and web members 172, 174 and 176, the righthand end of the truss being a mirror image of the left side of the truss. In setting up the jig assembly to produce a gable type truss of this type, the following steps are taken.

With the desired dimensions of the truss known, the various reaction pads are properly positioned along the guide bars according to previously recorded data by simply aligning the pointers on the respective reaction pads with the appropriate indicia on the underlying tape. The heel reaction pad 26 is placed at a point representing the end of the bottom chord or tie beam 62 and the U3 point reaction pad is positioned at approximately one-third the length down the bottom chord at the point where the web members 172 and 174 meet the bottom chord 62. The splice reaction pad is positioned to hold together the two pieces of lumber which form the bottom chord. The peak reaction pad 16 is positioned so as to hold together the top chords 168 and 170 and the web members 174 and 176.

The l/ 3 point reaction pad 136 is moved both vertically (by moving the connector plates and along guide bars 116 and 114) and horizontally (by movement of the reaction pad 136 along the movable guide bar 113) to the position where the web member 172 abuts the top chord 168. Each of the reaction pads are then secured in place on their respective guide bars by tightening their various locking screws or bolts.

Suitable connector plates are then dropped onto the various reaction pads where they are positioned by any suitable locating means such as that illustrated in copending application Serial No. 228,662.

The various chord and web members used to form the truss are then placed on the jig over these plates and are secured in position by lock-ing the various locking devices 64, 140, 148, 150, 152 and 156. This is accomplished by moving the handles 102 on the locking devices from the position shown in solid lines in FIGURE 2 to the position shown in dashed lines in that figure. This moves the arcuate plate 76 on the ends of the pressure plungers 72 from the broken line position shown in FIGURE 2 to the solid line position to hold the lumber in the desired relationship.

As the handle 102 reaches the broken line position shown in FIGURE 2, the locking plunger 82 (FIGURES 3 and 4) snaps into the aperture 86 in the barrel 66 thereby loeking the plunger block 78 in its rightmost position (FIGURE 3) and forcing the pressure plunvgers against the lumber to hold the lumber in position. The handle 102 is now moved from the broken line position shown in FIGURE 2 to the solid line position to ready the locking devices for automatic unlocking.

The truss is now jigged and ready for pressing and may be placed between the platens 178 and 180 of any suitable press, as is seen in FIGURE 3. As the platen 178 descends it presses the teeth 162 and 164 of the connector plates into the wooden member 62 to form the desired butt joints. At the very termination of the press stroke, the platen 17 8 engages the end of the release spring 88 on the locking device thereby forcing the dimple 92 into the aperture 86 to depress the locking plunger 82 and release the plunger block '78. The plunger block 78 thereby springs to the unlocked position under the influence of the plunger spring 104 and the now completed truss is ready for removal from the jig immediately upon its withdrawal from the press.

It will be apparent from the foregoing that the jig and locking devices of this invention greatly facilitate the unloading of completed trusses from the jig assembly and thereby speed the rate of truss production. The locking devices are simple in construction and are rugged and durable in nature so as to require practically no maintenance. As a result, the jig assembly and locking devices of the invention provide for the more rapid economical production of roof trusses or any other monoplane prefabricated structural elements.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrict-ive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States letters Patent is:

1. A jig assembly for holding wooden members in predetermined positions during a pressing operation carried out by a press having a pressing member movable in a first direction, said jig assembly including a jig pad and a locking means on said pad, said locking means comprising a fixed member against which a first wooden member may be abutted, and a movable member movable in a second direction different than said first direction into engagement with a second wooden member to lock it aganst the reaction of said fixed member, actuating means for said movable member to move it into locking position, and release means for releasing said movable member in response to movement of said press in said first direction whereby, upon release, said movable member is free to move in a direction opposite to said second direction.

2. A jig assembly for holding wooden members in predetermined positions during a pressing operation carried out by a press, including a jig pad and at least one locking means on said pad, said locking means comprising a member fixed to said pad against which a wooden member may be abutted, and a movable member movable into engagement with a wooden member to lock it against the reaction of said fixed member, actuating means associated with said movable member to move it into locking position, a press for acting on said wooden member and release means for releasing said movable member when said release means is engaged by said press.

3. A jig assembly for holding wooden member-s in predetermined positions during a pressing operation, including a jig pad and a plurality of locking means on said pad, at least a plurality of said locking means being mounted for sliding motion over said pad, each said locking means comprising a reaction pad, a stop member atfixed to said reaction pad against which a wooden member may be abutted, and a movable member on said reaction pad movable into engagement with a wooden member to lock '3 it against the reaction of said stop member, actuating means for said movable member to move it into locking position, a press for acting on said wooden member, and release means for said movable member for releasing said movable member in response to movement of the press accomplishing said pressing operation.

4. A jig assembly as set out in claim 3 including elongated guide bars secured to said jig pad, said reaction pads mounted for sliding motion over said jig pad being slidably mounted on said guide bars.

5. A jig assembly as set out in claim 3 wherein said locking means are adjust-ably mounted on said reaction pads.

6. A jig assembly for holding wooden members in predetermined positions during a pressing operation carried out by a press having a pressing member movable in a first direction, including, a jig pad, a reaction pad adjustably mounted on said jig pad for movement in at least one direction perpendicular to said first direction, a fixed member mounted on said reaction pad and adapted to have a first wooden member butted against it, a movable member movable into engagement with a second wooden member to lock it against the reaction of said fixed member, said movable member moving in a second direction different than said first direction, cam means associated with said movable member to tense a spring to lock said movable member, and release means for releasing the tension of said spring and unlocking said movable member when said release means is engaged and moved by said press whereby said movable member is free to move in a direction opposite to said second direction.

-7. A jig assembly as set out in claim 6 wherein said movable member comprises a wood engaging plate attached to a slide, said slide matingly engaging a mounting member, a block slidably mounted in said mounting member, a spring between said block and plate unging said block and plate in different directions, said cam member being eifective to tense said spring.

8. A jig assembly as set out in claim 6 wherein said movable member comprises a wood engaging plate attached to one end of a tube, a barrel slidably receiving the other end of said tube, a plunger block slidably mounted in the other end of said barrel, a spring in said tube and abutting said plunger block to urge said plate and block in different directions, said cam engaging said block to move it into said barrel to tense said spring.

9. A jig assembly as set out in claim 8 wherein said release means comprises a locking plunger slidably mounted in said block and spring urged into engagement with the inside of said barrel, said barrel having an aperture therein through which said locking plunger is moved when said spring is tensed to lock said block in position, said release means including means for moving said locking plunger back out of said aperture on operation of said press to release said block.

10. A jig assembly as set out in claim 9 wherein said last named means comprises an elongated spring attached to said barrel and overlying said aperture, said spring having a projection overlying said aperture and adapted to enter said aperture to move said locking plunger out of said aperture.

11. A reaction pad for a jig assembly comprising a fixed member adapted to have a wooden member butted against it, a movable member movable into engagement with a wooden member to lock it against the reaction of said fixed member, cam means associated with said movable member to tense a spring to lock said movable member, and release means for releasing the tension of said spring and unlocking said movable member when said release means is caused to move.

12. A reaction pad as set out in claim 11 wherein said movable member comprises a wood engaging plate attached to a slide, said slide matingly engaging a mounting member, a block slidably mounted in said mounting member, a spring between said block and plate urging said block and plate in different directions, said cam member being effective to tense said spring.

13. A reaction pad as set out in claim 11 wherein said movable member comprises a wood engaging plate attached to one end of a tube, a barrel slidably receiving the other end of said tube, a plunger block slidably mounted in the other end of said barrel, a spring in said tube and abutting said plunger block to urge said plate and block in different directions, said cam engaging said block to move it into said barrel to tense said spring.

14. A reaction pad as set out in claim 13 wherein said release means comprises a locking plunger slidably mounted in said block and spring urged into engagement with the inside of said barrel, said barrel having an aperture therein through which said locking plunger is moved when said spring is tensed to lock said block in position, said release means including means for moving said locking plunger back out of said aperture to release said block.

15. A reaction pad as set out in claim 14 wherein said last named means comprises an elongated spring attached to said barrel and overlying said aperture, said spring having a projection overlying said aperture and adapted to enter said aperture to move said locking plunger out of said aperture.

References Cited by the Examiner UNITED STATES PATENTS 814,200 3/1906 Gibson 83-384 1,430,226 9/1922 Goodreau 269208 X 2,983,292 5/1961 McKinley 144288 WILLIAM W. DYER, JR., Primary Examiner.

ROBERT C. RIORDON, Examiner.

Claims (1)

1. 2. A JIG ASSEMBLY FOR HOLDING WOODEN MEMBERS IN PREDETERMINED POSITIONS DURING A PRESSING OPERATION CARRIED OUT BY A PRESS, INCLUDING A JIG PAD AND AT LEAST ONE LOCKING MEANS ON SAID PAD, SAID LOCKING MEANS COMPRISING A MEMBER FIXED TO SAID PAD AGAINST WHICH A WOODEN MEMBER MAY BE ABUTTED, AND A MOVABLE MEMBER MOVABLE INTO ENGAGEMENT WITH A WOODEN MEMBER TO LOCK IT AGAINST THE REA-

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