Claims:
Having fully described an operative embodiment of this invention, I now claim
1. An apparatus for making large wood trusses and the like devices formed of elongated spaced apart coplanar chords interconnected by web members whose ends are abutted against and joined to the respective chord members by metal fastener plates positioned over the joints and having struck-out teeth embedded into the portions of the chord and web members at said joints comprising:
2. An apparatus as defined in claim 1, and said table being formed of numerous closely spaced rollers extending transversely of the table for roller supporting the plate for endwise sliding from one end of the table to the other.
3. An apparatus as defined in claim 1, and including a lower press roller mounted beneath and in parallel alignment with the first mentioned press roller, with the uppermost edge of the lower press roller being substantially in the uppermost plane defining the top surface of the table, whereby the plate, chord and web members and fastener plates are squeezed together as a unit between the two press rollers for embedding the teeth of the fastener plate into said members.
4. An apparatus for making large wood truss-like devices formed of elongated spaced apart, coplanar wood chord members interconnected by web members, with the adjacent ends of said members being abutted and fastened together by metal fastener plates laid over the abutted joints in face to face relationship therewith and secured to the members by fastener plate struck-out teeth which are embedded into the adjacent member portions, comprising:
5. An apparatus as defined in claim 4, and including a lower press roller mounted beneath and in parallel alignment with the first mentioned roller, with the uppermost edge of the lower press roller being substantially in the uppermost plane defining the surface of the table, whereby the plate, chord and web members and fastener plates are squeezed together as a unit between the two press rollers for embedding the teeth of the fastener plates into said members.
6. A method for making large wood trusses and the like devices formed of elongated, spaced apart coplanar chords interconnected by web members whose ends are abutted against and joined to the respective chords by toothed metal fastener plates positioned over the opposite faces of each of the joints with their teeth embedded in the adjacent chord and web member portions, comprising:
7. A method as defined in claim 6 and wherein said plate is arranged upon an elonated table whose top is formed of numerous rollers arranged for supporting the plate for endwise sliding movement, with the table top transversely extending beyond both sides of the axis of the roller press and including the step of sliding the plate endwise upon said table top rollers through the roller press.
Description:
BACKGROUND OF INVENTION
The apparatus and method herein relates to the fabrication of wood trusses, of various shapes and sizes, used as trusses or joists in building construction, such as for roof, deck and floor supports. Such trusses are made of elongated wood chord members which are interconnected by wood web members, with the chords and web members fastened together at abutted joints by means of toothed metal connector or fastener plates applied to the opposite faces of the joints with their teeth embedded in the wood. An example of this type of truss construction is disclosed in my U.S. Pat. No. 3,651,612 issued Mar. 28, 1972. An example of suitable connector or fastener plates is disclosed in my U.S. Pat. No. 3,633,454 granted Jan. 11, 1972.
The fabrication of such type trusses whether of the parallel chord joist type or the intersecting chord, V-shape roof truss type, requires considerable hand labor and considerable time in assembly and particularly in the embedding of the connector plates into the wood members. Thus, the invention herein relates to an improved system and apparatus for more rapidly and efficiently fabricating such trusses and particularly securing the connector plates thereto, which system employs relatively simple apparatus which reduces labor requirements considerably.
SUMMARY OF INVENTION
The invention herein comtemplates forming wood trusses upon a large metal support plate on which pre-cut truss members are properly aligned and including loosely positioning connector plates over the joints upon one face of the assembled truss members, and then sliding the plate endwise upon a low friction support table through a roller type press to embed the connector plates and thereafter turning the partially assembled truss upside down, positioning connector plates upon the opposite joint faces and running the plate with the truss back through the truss for embedding plates into the opposite joint faces.
The support plate is of double truss width and at least as long as a single truss. Thus, four table positions are provided upon the apparatus, namely, (1) a first loading position where the truss members are assembled and clamped upon one side of the support plate and the connector plates are located upon the joints, (2) a second position at the opposite end of the table beyond the press from which second position the truss may be removed and turned upside down into (3) a third position on the opposite side of the support plate and table so that while plates are positioned manually over the opposite faces of the joints, another truss may be assembled upon the support plate at the second position, duplicating the operation of the first position, and thereafter, the plate may be run back through the press to the opposite end of the table where the now completed truss is removed from (4) the fourth position and the partially assembled truss at the first position is inverted and placed into the fourth position where the cycle is repeated.
With the foregoing system, several workmen located at one long side of the table are able to load truss members onto the support plate at either position one or position two and workmen located at the opposite side of the table can unload completed trusses as well as position connector plates over the inverted trusses to overlap the opposite faces of the joints. As can be seen, one long side of the table has two loading positions and the other long side has two unloading positions, with a press located between the opposite ends of the table for embedding the plates between the various positions.
The foregoing system and apparatus simplifies the handling of the raw materials, namely, the pre-cut chord and web members and also simplifies the removal of completed trusses, considerably reduces labor and handling in the fabrication and thus speeds up the fabrication of trusses as well as substantially reducing the costs thereof.
These and other objects and advantages will become apparent upon reading the following disclosure, of which the attached drawings form a part.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of the apparatus herein, with the support plate located at one end of the table and truss members loaded upon one side of the support plate.
FIG. 2 is a schematic plan view of the system and the various work stations thereof.
FIG. 3 is an enlarged, cross-sectional view taken generally in the direction of arrows 3--3 of FIG. 1.
FIG. 4 is an enlarged elevational view of one truss joint.
DETAILED DESCRIPTION
Referring to FIG. 1, the apparatus 10 is formed of an elongated, relatively narrow table 11 formed of two end to end arranged table halves 12 and 13 respectively. Preferably the tables are formed of a large number of rollers 14 arranged side by side and rollingly secured to and supported by a suitable frame 15 in turn supported above ground level by legs 16.
A roller press 17 is located at roughly the middle of the table 11 and consists of an upper roller 18 and a lower roller 19, each arranged transversely of the table, with one roller spaced apart a short distance above the other. The press rollers are supported by suitable support legs 20 which permit the rollers to rotate. Preferably, at least one of the rollers is motor driven by a suitable motor and connection 21 (shown schematically in FIGS. 1 and 2).
An elongated, flat support plate 24, preferably formed of a thin but relatively rigid sheet of metal is supported upon one of the halves of the table. The support plate is at least as long as the truss to be fabricated and double the width of such trusses. The support plate is divided into two elongated parts, namely, a load side or part 25 and an opposite unload side or part 26. Such plate may be made of a single sheet of suitable length and width or alternatively where the size is too great, it can be made of two long, parallel sheets which are coplanar and interconnected at their centers in some suitable way to form a single sheet unit of double truss width.
In operation, as shown schematically in FIG. 2, the support plate 24 is arranged upon one of the two table halves. The table itself is divided into four stations, namely, load stations one and two located along one edge and the opposite ends of the table, and unload stations three and four similarly located on opposite ends of the table relative to the press.
Two piles 30 and 30a of pre-cut chord members 32 and web members 33 are arranged at the load stations, that is, at the opposite sides of the press alongside of the one edge of the table.
Workmen operating the apparatus lift from the pile 30 at station one the required number of chord members and web members and place them upon the load side 25 of the support plate 24. Locator means formed upon the plate guide the location of the members. Thus, the plate is provided with a central guide bar 34 extending its length to function as a locator for one long chord member. A second guide bar 35 is loosely positioned upon the upper surface of the plate at a distance from the central guide bar 34. Suitable mechanical clamps 36, of any conventional construction, are arranged to clamp the movable guide bar 35 towards the fixed central guide bar 34. Thus, a first chord may be positioned against the fixed guide bar 34, a second chord member against the movable guide bar 35, with the web members 33 located between to form abutting types of joints. With this arrangement, the wood members which are typically formed of conventional so-called 2×4's strips of lumber may be arranged with their wider cross-sectional edge upwards as illustrated in FIG. 3.
Once the chord members 32 and the web members 33 are properly abutted, the clamps 36 may be applied to shove the movable guide bar 35 towards the fixed guide bar 34 and thereby tightly hold the parts in place. Other suitable clamping means may be used. Also, the guide bar may be changed in shape or angularity, that is, for example, being V-shaped to accommodate a V-shaped truss as opposed to a parallel chord truss described above.
At this point, the workmen lay over each of the abutted joints a metal truss connector plate 39 which comprises a flat sheet of metal having struck-out teeth 40. The teeth rest upon the upper surfaces of the wood members.
Next, the entire plate 24 is slid endwise to the opposite half of the table so as to pass between the upper and lower press rollers 18 and 19 which are spaced apart a sufficient distance to accommodate and squeeze together the plate 24, the truss members and the connector plates. As the plate and truss passes between the two rollers, the connector plates are squeezed downwardly so that their teeth 40 embed in their wood members.
At this point, as shown in dotted lines in FIG. 2, the plate is now located at stations 2 and 3. The workmen unclamp the truss and turn it upside down so as to flip it from station 2 into station 3 where it may be reclamped. At that point, workmen located at station 3 position connector or fastener plates over each of the now exposed joint faces while simultaneously workmen in station 2 load a new truss into position by taking chord members 32 and web members 33 from pile 30a. Likewise, they position connector plates over the joints. The same workmen from station 1 normally walk to station 2 to perform the loading operation.
After the truss is loaded at station 2 and the exposed joint faces are covered with plates at station 3, the plate 24 is again rolled endwise back through the press so that it now is aligned with stations 1 and 4. The workmen now return from stations 2 and 3 to stations 1 and 4.
At that point, the workmen at station 4 remove the completed truss 38 and put it in a pile in back of them, while simultaneously the workmen in station 1 release the truss at that position, and flip it over into station 4. Again a new truss is assembled at station 1, plates are applied to the exposed joint faces at station 4, and the support plate is again rolled back through the press to repeat the cycle.
Since a typical joist type truss, as illustrated in the drawings may run in the order of 16 to 32 feet in length, the table is of considerable length as is the plate 24. A single crew of three workmen at station 1 is sufficient to handle the loading at both station 1 and station 2 while a crew of two workmen at station 3 can handle both stations 3 and 4. Of course, a separate crew may be used at each of the stations. However, it has been found that using only one crew at each of the two sides of the tables, each crew to handle two stations, walking back and forth between them, actually expedites the work, avoiding boredom and helping control and improve quality as the workmen remain more alert due to the movement back and forth.