Adjustable locator for assembly of trusses

A locator for locating and holding a structural member in engagement with an adjacent structural member at a predetermined position of an assembly apparatus during a truss assembly operation. The locator includes a cylindric sleeve having an outer wall configured for engaging the structural member and a bore extending through the sleeve defining an inner wall sized for placement around a stop of the assembly apparatus. The bore is eccentrically positioned in the sleeve. The sleeve is portable, may be secured to the apparatus free from fixed connection, and is rotatable about the stop for adjusting a magnitude of force applied by the sleeve to the structural member.

BACKGROUND OF THE INVENTION

This invention relates generally to the assembly of trusses, and in particular to a locator for holding a structural member at a predetermined position on an assembly apparatus.

Pre-manufactured structural frameworks, such as trusses, are widely used in the construction industry for forming a roof, wall panel, floor, or other building component. Each truss includes a collection of structural members, typically in the form of wooden timbers, held together by connectors, such as connector (“nailing”) plates pressed into the timbers. The truss is assembled to the correct specifications at a factory and then shipped to a construction site. A gantry press apparatus is frequently used to facilitate efficient assembly of the truss. It features a table on which the timbers and connector plates are placed at desired relative positions to form the particular truss configuration.

Conventionally, the table has cylindrically-shaped stops (often referred to as “pucks”) for setting positions of timbers. The stops are slidable along spaced opening channels in the table and are locked at predetermined positions in the channels dependent upon the shape of the truss which is required. The timbers are then located against the stops to define the shape of the truss. Connector plates are placed at locations where adjacent timbers intersect. A motorized roller apparatus (i.e., the gantry) then travels along the table to press integral teeth of the connector plates into the timbers thereby joining them together.

Ideally, each timber should be in tight abutment against adjacent timbers when placed on the table so that the assembled truss will be strong and loads will be effectively transferred between the timbers making up the truss. Unfortunately, some timbers have imperfections, non-linearities, or warp which form one or more gaps between adjacent structural members or between a stop and a structural member. If not eliminated, these gaps would substantially degrade the strength of the assembled truss.

Typically, an operator visually inspects an assembly of structural members prior to activating the roller apparatus. Upon discovering a gap, the operator inserts a wooden wedge between a stop and timber to press the timber into firm engagement with an adjacent timber. Unfortunately, these actions are detrimental to an efficient assembly process and can cause substantial downtime. Wedges are prone to slip or break during installation, fall to the floor at a location from which retrieval is difficult, or be inadvertently nailed into assembly with the truss.

Consequently, some systems of the prior art have featured devices for pressing timbers against adjacent timbers to eliminate gaps. However, these devices have been complex or have been fixedly attached to the apparatus such that it is time consuming to move the device to a second location where gapping occurs, or to another, similar apparatus.

SUMMARY OF THE INVENTION

Among the several objects and features of the present invention may be noted the provision of a locator for pressing a structural member into engagement with an adjacent structural member; the provision of such a locator which is adjustable for applying a pressing force of variable magnitude; the provision of such an apparatus which is readily portable for use at a second location; the provision of such a locator which fits upon existing equipment; and the provision of such a locator which is inexpensive to manufacture.

In general, a portable locator according to the present invention locates and holds a structural member in a predetermined position on a worksurface of an assembly apparatus during an assembly operation wherein at least one fastener is installed to connect the structural member to another structural member. The locator comprises a body configured for securement to the assembly apparatus free from fixed connection thereto at a first installed position from which the body may engage the structural member to press against the structural member for use in holding the structural member at its predetermined position on the worksurface. The body is adapted to be freely removed from the first installed position without releasing any fixed connection for movement to a second installed position on the assembly apparatus for ready securement thereto free from fixed connection.

In another aspect, an extender according to the present invention is for a stop of an assembly apparatus. The extender presses a structural member into engagement with an adjacent structural member at a predetermined position on a worksurface of the assembly apparatus during an assembly operation wherein at least one fastener is installed to connect the structural members at the predetermined position. The stops project above the worksurface for guiding positions of the structural members. The extender comprises a sleeve sized and shaped for placement at an installed position generally around one of the stops and extending a lateral reach of the stop. The sleeve has an inner wall for engaging the stop and an outer wall for engaging the structural member and applying force thereto. The sleeve defines a radial thickness disposed between the inner and outer walls. The inner wall is eccentrically positioned relative to the outer wall such that the radial thickness varies in a circumferential direction around the sleeve. The sleeve is rotatable about the stop such that rotation of the sleeve alters the radial thickness of sleeve positioned between the stop and structural member to thereby adjust a magnitude of force applied by the sleeve to the structural member.

Corresponding reference characters indicate corresponding parts throughout the views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and in particular toFIG. 1, a truss assembly apparatus according to the present invention is indicated generally at10. The apparatus10includes a truss table12on which structural members14and connector plates16may be positioned at a desired configuration for assembly to form a truss. Outer rails18are provided for guiding movement of a roller assembly20relative to the truss table12to press connector plates16into the structural members14to connect the structural members.

In the illustrated embodiment, the structural members14are wooden timbers, but they could be made of other materials (e.g., plastic, steel, etc.) without departing from the scope of the present invention.

The truss table12has a plurality of parallel, elongate panels22providing a worksurface for placement of timbers14. A slot24is left between adjacent pairs of panels22suitable for placement of conventional positioning stops30. Each stop is slidable in translation along the slot24and is capable of being fixed along the slot for correct location and placement of timbers14on the worksurface to form a truss. The stops30project above the worksurface for guiding positions of the timbers14. Typically, each stop30has a cylindric shape.

Because the truss assembly apparatus10is conventional, it will not be described in further detail. Reference is made to co-pending U.S. patent application Ser. No. 10/233,034, filed Aug. 30, 2002 and entitled “Truss Assembly Apparatus,” which is hereby incorporated by reference, and to the following U.S. Patents for further background regarding truss assembly systems, each of which is also hereby incorporated by reference:

A portable locator according to the present invention, indicated generally at40, is used with the truss assembly apparatus10for locating and holding a timber14in engagement with an adjacent timber. Referring toFIGS. 4and5, the locator40has a low-profile cylindric sleeve42(broadly, a “body”) and a handle44secured to the sleeve for manually raising, lowering, and rotating the sleeve. The sleeve42has an outer wall46for engaging the timber and a first central axis48associated with the sleeve and the outer wall. The first central axis48extends along the axis of rotation of a cylinder defined by the outer wall46.

An opening50extends through the sleeve42which is eccentrically positioned relative to the outer wall46of the sleeve. The opening50is defined by a cylindric bore forming an inner wall52. The opening50and inner wall52are associated with a second central axis54extending along the axis of rotation of a cylinder defined by the inner wall. The opening50has a size and shape corresponding with one of the stops30such that the sleeve42may be secured at an installed position (FIG. 2) on the apparatus10by lowering the sleeve and placing it around the stop with the stop being received in the opening of the sleeve. The inner wall52of the sleeve is adjacent to the stop30(either engaging or closely spaced with the stop). For example, for use with a conventional cylindric stop with an external diameter of 2.00 inches, the opening50is defined by a cylindric bore having a diameter of 2.01 inches. The slightly larger diameter of the bore facilitates slidable movement of the inner wall52relative to the stop30while still maintaining the sleeve42firmly secured to the stop. Preferably, the sleeve42and opening50have heights which are approximately the same as the height of a stop30(1.14 inches in the preferred embodiment) to completely cover the stop. However, the heights of the sleeve and stop may be different from each other. The opening50extends completely through an entirety of the sleeve42, although it is understood that a sleeve with an opening which extends only partially through the sleeve, or has a non-circular inner or outer wall, does not depart from the scope of this invention.

The first and second axes48,54are parallel and non-coincident such that the opening50is eccentrically positioned in the sleeve42relative to a center of the sleeve and the outer wall46. Consequently, the sleeve42has a radial thickness T (FIG. 4) between the inner and outer walls52,46which varies in a circumferential direction around the sleeve. Although in the preferred embodiment, the opening50is enclosed within the sleeve42(i.e., positioned within the outer wall46), the opening could be positioned such that it removes a portion of the outer wall and forms an open crescent-shaped notch (not shown) in one side of the sleeve.

At the installed position (FIGS.2and3), the sleeve42generally encircles the stop30and the radial thickness is disposed between the stop and the timber14. The sleeve42is rotatable relative to the apparatus10with a center of rotation defined by the second axis54. As shown inFIG. 2, a gap60is formed between a timber14and an adjacent timber. The gap may have any size, including a very small size, and may be found between edges of timbers which are parallel (as inFIG. 2) or non-parallel. The stop30with sleeve42may be slid along its slot24for proper positioning, if needed, and secured at a different location. Rotation of the sleeve42adjusts the radial thickness of the sleeve positioned between the stop30and the timber14to thereby adjust the magnitude of force with which the sleeve presses the timber against the adjacent timber. After rotation (FIG.3), a portion of the sleeve42having a greater radial thickness is positioned between the stop30and timber14and consequently the gap60is eliminated. Thus the locator40functions as a cam for guiding positions of timbers. The angle of rotation corresponds with a magnitude of force applied to the timber14and the distance the timber is moved. Accordingly, the sleeve42is rotated until the timber14firmly abuts the adjacent timber. It is understood that locators which are not rotatable do not depart from the scope of this invention.

Significantly, the sleeve42may be secured to the apparatus10free from fixed connection. Thus the locator is fully portable and may be quickly installed and used by placing it on a stop30. Subsequent to the assembly operation, the sleeve42may be freely removed from the installed position without releasing any fixed connector for movement to a second installed position on the apparatus or to a second assembly apparatus for ready securement thereto free from fixed connection.

The locator40is formed of a suitable strong and rigid material. In the preferred embodiment, the locator is made of cold rolled, AISI-SAE 1018 steel, although other materials, including non-metallic materials, do not depart from the scope of this invention. The locator40is manufactured by slicing a segment from a solid round shaft. That shaft segment forms the sleeve42, and a hole is drilled through the segment forming the opening50. A lathe or a CNC milling machine may be used to improve the circularity of the sleeve42and opening50and any sharp corners may be rounded. The handle44is a solid rod of length suitable for gripping and is secured to the sleeve42such as by welding. For ease of use, the handle44is preferably attached in a radial direction relative to the sleeve42and at a slight upward angle of inclination in a direction moving away from the sleeve, such as four degrees. Other handle orientations and sleeves without handles do not depart from the scope of this invention.

In an alternate embodiment (not shown), the sleeve42may be more permanently secured to a stop30for repeated uses therewith. The inner wall52is modified to include an engagement surface (not shown) such as an annular, vertically-facing shoulder or lip. The stop30is modified with a corresponding engagement surface such as a circumferential shoulder or groove. The locator and stop may be joined together into an assembled unit with the corresponding surfaces in engagement. The assembled unit may then be slid along channels in the table or locked at a predetermined position for repeated use in assembling trusses. The engaging surfaces do not impede rotation of the sleeve relative to the stop. Other systems for securing the sleeve and stop do not depart from the scope of this invention.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results obtained. The locator40may be used with existing equipment of a truss assembly apparatus to press a structural member into engagement with an adjacent structural member. The locator is adjustable for applying a pressing force of variable magnitude. The locator is portable, may be secured to the apparatus without fixed attachment, and is reliable in operation.