Woodworking – Shaping machine – Pattern
Reexamination Certificate
1998-12-09
2001-01-23
Bray, W. Donald (Department: 3725)
Woodworking
Shaping machine
Pattern
C144S144100, C144S371000, C409S130000, C033S638000
Reexamination Certificate
active
06176281
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a frame guide which enables a hand-held router to be used to rout various sizes and shapes of square, rectangular and parallelogram shaped grooves or recesses, in a controlled and precise manner, and on any size of workpiece.
BACKGROUND OF THE INVENTION
In order to rout various sizes of square and rectangular grooves and recesses, various designs for adjustable rectangular guides have been proposed. Examples of these designs are found in the literature including Spielman, P.,
The New Router Handbook
(New York: Sterling Publishing Co., 1993) at pp. 211-212; and Spielman, P.,
Router Jigs and Techniques
(New York: Sterling Publishing Co., 1988) at pp. 220-223. While these prior art designs teach an adjustable four-sided frame for guiding a router, they suffer from a number of limitations including the requirement of having to adjust each corner of the frame in order to set the desired length and width. In addition, these prior art framing guides are designed so that the router base rides on top of the frame guide members rather than the router base being contained within the frame guide members, thus requiring the router operator to hold the router partly on and partly off a supporting base. Furthermore, the rectangular frame guides found in the prior art do not allow any flexibility in routing grooves or recesses which are somewhat off-square, i.e. a parallelogram, or which do not have any parallel sides, i.e. a trapezoid. In addition, it is not possible or practical to use the prior art frame guides on surfaces which are vertical or angled.
SUMMARY OF THE INVENTION
The present invention provides a frame guide for use in conjunction with a hand-held router to form various sizes and shapes of square and rectangular grooves or recesses, and which is intended to overcome the limitations of prior art devices as identified above.
In a first aspect, the present invention provides an adjustable frame guide, defining a quadrilateral, having a first pair of sides and a second pair of sides with each second side extending between the first sides, the quadrilateral being for guiding a router having a base for sliding movement relative to the frame guide, the frame guide comprising:
a pair of first frame members extending along the first sides of the quadrilateral, each first frame member having first and second ends;
a pair of second frame members extending along second sides of the quadrilateral and each second frame member having first and second ends;
a joint formed between the first end of one first frame member and the first end of one second frame member, a joint formed between the first end of the other first frame member and the first end of the other second frame member, a joint formed between the second end of one first frame member and the second end of the other second frame member and a joint formed between the second end of the other first frame member and the second end of the one second frame member, the first and second frame members overlapping at the joints; and
a connection means provided at each joint, wherein the connection means include slots in each of said frame members at respective second ends thereof, each of said slots forming an elongate aperture through one of said frame members at said respective second ends, said slots overlapping and intersecting at said joints formed at said second ends and, wherein, said connection means enable the frame members to be rigidly secured together and enable at least the length of each side of the quadrilateral to be adjusted.
Preferably, the first and second frame members of the adjustable frame guide includes a hole at respective first ends thereof, whereby there is one pair of joints with overlapping slots and another pair of joints with overlapping holes, the overlapping holes providing an inextendable joint, and the overlapping slots providing an adjustable joint enabling simultaneous adjustment of the length of all sides of the adjustable frame guide.
More preferably, the connection means, at each joint, includes an elongate shaft and clamping means for clamping overlapping ends of the first and second frame members together, the elongate shafts extending through the holes and the slots, to align the first and second frame members.
The elongate shafts can comprise screw shafts, wherein the clamping means comprises, for each joint, a screw head at one end of a corresponding screw shaft and a threaded fastening member rotatably mounted on the screw shaft at the other end thereof.
Conveniently, the second frame members extend over the top of the first frame members. However, it will be appreciated that each frame member could include one lower end and one upper end, with each joint then having one upper end on top of one lower end. In this manner, the first and second frame members do not obstruct one another, and enable free angular movement between the first and second frame members.
Preferably, the first frame members are generally elongate and include lower surfaces for abutting a workpiece and are of substantially uniform cross-section, and the second frame members are generally elongate and of substantially uniform cross-section and extend above the first frame members and wherein a guide block is mounted below each second frame member and has a lower surface generally coplanar with the lower surfaces of first frame members. The guide blocks also have an inner vertical surface generally coplanar with the inner vertical surface of each corresponding second frame members.
This arrangement provides the possibility of sometimes limiting pivotal movement at some of the corners, so as to ensure that corners are square. Thus, where two joints are formed solely by holes in the frame members, there is no possibility of extension. Then, when the guide blocks abut closely against the first frame members, a perpendicular end surface on the guide blocks will keep the frame members square. An adjustment in size of the rectangle defined by the frame guide will then occur at the other two joints. This is convenient, as it is then necessary to loosen only two joints to adjust the frame guide.
It will also be appreciated that for some applications, it is desirable to be able to pivot the frame members to angles other than square. Thus, the connection means provided at each joint can enable the first and second frame members to pivot relative to each other to enable the first and second frame members to form the sides of a parallelogram or trapezoid.
REFERENCES:
patent: 3985168 (1976-10-01), Lundquist
patent: 4281694 (1981-08-01), Gorman
patent: 4294297 (1981-10-01), Kieffer
patent: 4373562 (1983-02-01), Vernon
patent: 4434824 (1984-03-01), Bussey
patent: 4718468 (1988-01-01), Cowman
patent: 4913206 (1990-04-01), Altinbasak
patent: 5040581 (1991-08-01), Takashima
patent: 5048580 (1991-09-01), Smith
patent: 5052454 (1991-10-01), Meinhardt
patent: 5203389 (1993-04-01), Goodwin
patent: 5383503 (1995-01-01), Johnson
Bereskin & Parr
Bray W. Donald
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