US2941484A

US2941484A - Trussed rafter

Info

Publication number: US2941484A
Application number: US502599A
Authority: US
Inventors: Marsh Fayette Elam
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-04-20
Filing date: 1955-04-20
Publication date: 1960-06-21
Anticipated expiration: 1977-06-21

Description

June 21, 1960 F. E. MARSH 2,941,484

' 'TRUSSED RAFTER Filed April 20, 1955 2 Sheets-Sheet 1 INVENTOR. 541 5775 ELAM MflPJ/ ATTOR/YEK F. E. MARSH TRUSSED RAFTER June 21, 1960 2 Sheets-Sheet 2 Filed April 20, 1955 INVENTOR. FAYETTE .ELAM MARSH ATTOIPNEL/ United States Patent TRUSSED RAFTER Fayette Elam Marsh, 1025 N. Lincoln Street,

Hastings, Nebr.

Filed Apr. 20, 1955, Set. N0. 502,599

3 Claims. (Cl. 108-23) This invention relates to a trussed rafter and more particularly with one fabricated of wood and adapted to be folded into a relatively small area to facilitate easy handling and shipment.

In the building trade there is an increasing appreciation of the many advantages of the trussed rafter for the roof structure, particularly in the smaller frame buildings, such as an individual residence or farm buildings.

However, one of the disadvantages encountered in this type of rafter is the fact that they land themselves most economically to mass production in a centrally located factory, but they are extremely hard to handle and expensive to ship, particularly if any great distance is involved.

There are two ways in which the manufacture or assembly of trussed rafters are traditionally handled. One, of course, is the previously mentioned factory assembly and shipment as a complete unit. Another method has been to precut the various sections and provide the builder with the jig, which might be used on the building site to guide the construction workers in the assembly of the unit.

- .The last method, while overcoming the objection of bulk, which is the disadvantage encountered in shipment, places an extra burden upon the builder and reduces the advantages of mass production and the consequent economy.

It is therefore an object of my invention to provide a trussed rafter which may be mass produced in a centrally located factory, and yet shipped in small, compact bundles to the building site where it will be finally connected.

It is yet another object of my invention to provide a trussed rafter which employs a plurality of pivotal joints.

It is a still further object of my invention to provide a device of the type described in which provision is made for bracing members adapted to provide a small margin of adjustment.

Still another object of my invention is to provide a trussed rafter in which the lower chord may be spliced at the building site while the balance of the rafter is already connected.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and following specifications, wherein is disclosed a single exemplary embodiment of the invention, with the understanding, however, that such changes may be made therein as fall within the scope of the appended claims, without departing fiom the spirit of the invention.

In said drawings:

- Figure l is a side view of a trussed rafter constructed Figure 5 is a side view of the rafter, partially folded and disconnected at points provided for that purpose.

Figure 6 is a view in perspective of the crown plate showing the pivotal point within the plate in dotted lines. Figure 7 is a view in perspective of the splicing saddle in enlarged view, and

Figure 8 is a side view of the diagonal brace used for downwardly and outwardly to connect to the lower chord 10 by means of bolts .16 and 17. Twoadditional diagonal braces 18 and 19 are nailed in an outward position to the previously mentioned diagonal braces 13 and 14, and extend to the upper chord where they are nailed in position.

The lower chord consists of two sections 20 and 21.- These are separate, but are spliced together at their joining points by the steel saddle member 31.

The upper and lower chords are connected at their outer extremities by-

bolts

22 and 23. The inner ends of the upper chords are connected to the crown plate by

bolts

24 and 25.

It is appropriate to indicate here that the lower chord 10 is formed of a single thickness of timber, while the upper chords 11 and 12 .are formed of two spaced-apart planks, such as 26 and 27 of Figure 3.

While an ordinary bolt connection could be used at

joints

22, 23, 24 and 25, I prefer to use ring connectors as well as bolts, such as are shown at 28 and 29 of Figure 4. It will be noted that these are positioned between two adjoining planks in a recess cut for that pur-' pose. Of course the pivotal movement of two boards so connected is much easier and, at the same time, the loading is distributed over a wider area; therefore the strength of the joint is increased.

Referring now to Figure 5; it will be seen that a rafter constructed according to my invention is capable of being folded, using the crown plate 15 as the pivot point around which the entire motion of the various parts is centered.

The two lower chords, such as 21, being pivotally mounted on the bolt 23, and comprising only one thickness of lumber, can be folded upwardly between the two planks of the upper chord. The brace 13, which is also pivotally mounted'on the crown plate, may be folded inwardly and will lie along the edge of the folded upper and lower chords. This makes a complete folded assembly, such as is shown generally at 30. These two halves may then be brought together to make one small bundle.

The diagonal braces 18 and 19 may be packaged separately as well as the saddle member 31.

The diagonal braces are not incorporated in the structure by a pivotal joint for a particular reason. It is a well known fact that in cutting lumber, there should be a fairly large permissible tolerance. As a result, the truss, when fully assembled, may not be quite as rigid or in the exact form as would be desired. These two short braces can then be nailed into position, providing thereby a form of adjustment and giving absolute rigidity to the entire structure.

It will be noted that the saddle member servesas a splice means for the two lower chords and have at 11131111:

Patented J une 21, 1960 aged trusses can be shipped in a single truck or freight car than could be shipped were they fully assembled and nailed together, as is the conventional practice. It is also apparent that they are much easier to assemble on the building site and much more accurate than they would be were they comprised of simply precut lengths of lumber..

Although I have described a specific embodiment of my invention, it is apparent that modifications thereof may be made by those skilled in the art. Such modifications may be made without departing from the spirit.

and scope of my invention. as set forth in the appended claims.

I claim as my invention:

'1. In a foldable trussed rafter of the type described, a substantially rectangular crown plate comprising a single thickness of material, a pair of upper chord members pivotally attached to said crown plate and rotatable inwardly and outwardly from each other, said chord members each comprising a pair of planks positioned one on each side of said crown plate, the pivotal mounting points of said chord members being spaced apart on centers substantially twice the width of one of said chord members, a: pair of brace members pivotally mounted on said crown plate at a point below and rnid way of the aforesaid pivotal. mounting position of said chord members, said brace members being positioned one to each side of said crown plate and of a widthnot greater than the width of one of said chord planks to permitsaid brace members to lie therebetween and parallel thereto in the same plane as the adjacent planks of the adjacent chord members; a lower chord member comprising a co-linear plank in two sections; each section thereof being pivotally joined at an end of each to the outer end of'said respective upper chord members andbeing of a lesser length than said upper chord members, each section of said lower chord member being positioned 'to' befolded coextensive with and in between the opposed planks of said upper chordmembers, and splice means for connecting the two sections of said lower chord member, the positioning of said upper and lower chord members and brace members as aforesaid being such that when folded, the pairs of planks formingthe upper chord members and brace members on either face ofthe crown plate will lie in substantially the same plane parallel to each other and the sections lower chord member willlie between the separate planks of' their respective upper chord member and in substantially the plane of the single thickness of the crown plate.

2. In a device of the type described, a crown plate, upper" right and left chord members, each comprising a pair of spaced-apart planks positioned on either side of said crown plate and pivotally'attached'thereto in spaced relation to permit them to be pivoted inwardly to a spaced apart and parallel positon thereby leaving a measured space therebetween, avlower chord member comprising a co-linear plank in two sections, each section thereof being pivotally joined to the outer end' of said upper chord members and between said planks thereof, each section of the lower-"chord member being of slight- 1y lesser length than the adjacent upper chord'member,

whereby said sections of the lower chord member may be folded into said respective upper chord members, and brace means pivotally attached respectively against front and rear faces of said crown plate between the pivoted attachments of said upper chord members thereto and adapted to be secured to said lower chord memher, said pivotally mounted brace means being so positioned that they may be folded into positon to occupy said measured space between said pivoted upper right and left chord members, and splice means for joining the free ends of said two sections of co-line'ar plank constituting the lower chord member.

3. An article of manufacture of the type described comprising in combination an elongated crown plate of generally rectangular shape and of a thickness from front to back of substantially less than its length or height, a pair of right hand chord members attached pivotally at one end to one end of the crown plate and disposed one against the front and one against the back of said crown plate, a pair of left hand chord members attached pivotally at one end to the other end of the crown plate and likewise disposed one against the front and one against the 7 back of said crown plate, said right and left hand pairs of chord members extending parallel to each other and being spaced apart in their pivotal connections to said crown plate so as to leave a measured space therebetween said parallel extending chord members, a right hand lower chord member of lesser length than the right hand chord members and pivotaliy connected at one end to the other end of said right hand chord members and lying sandwiched therebetween and of substantially the same width as said right hand chord members, a left hand lower chord member of lesser length than the left hand chord members and pivotally connected at one end to the other end of said left hand chord members and lying sandwiched therebetween and of substantially the same width as said left hand chord members, a first brace member having one end lying adjacent the front of said crown plate, a second brace member having one end lying adjacent the rear of said crown plate, a common pivot connecting said ends of the first and second brace members to the crown plate at a point lying be tween said pivotal connections of said right and left hand chord members to the crown plate and spaced from a line joining the pivotal connections of said right and left hand chord members in a direction toward the other ends of said right and left hand chord members, said brace members occupying throughout their length a portion of said measured space between said right and'left hand chord members and being parallel to and each lying in a separate common plane with their respectively adjacent right and left hand chord members.

References-Cited in the file of this patent UNITED STATES PATENTS 457,418 Hodges Aug. 11, 1891 765,382 Fleming July 19, 1904 949,394 Daly Feb. 15, 1910 1,048,704 King Dec. 31, 1912 2,604,060 Hanson July 22, 1952' FOREIGN PATENTS 661,609 France 1929' OTHER REFERENCES Manual of Timber Connector Construction, page 2', 1939, by Timber Engineering Co.

Modern Timber Roof Trusses, 1940, page 2,Timb er Engineering Co.