US3529361A - Template for making a carpenter's trestle - Google Patents

Description

Sept. 22, 1970 H. PARSONS. JR

TEMPLATE FOR MAKIYNG A CARPENTER'S TRESTLE VINVN'I'OR. l Hownrzp PnrlsousJn.

ATTOLNEY United States Patent O 3,529,361 TEMPLATE FOR MAKING A CARPENTERS TRESTLE Howard Parsons, Jr., 157 Old New York Road, Port Republic, NJ. 08241 Filed Aug. 2, 1968, Ser. No. 749,756 Int. Cl. G01b 3/14 U.S. Cl. 33-174 2 Claims ABSTRACT OF THE DISCLOSURE A template for marking mortise grooves in a bench beam for receiving leg boards for a carpenters trestle comprises an elongated plate formed with a pair of rectangular cut-outs of different depths in opposite sides, respectively, of the plate, intermediate opposite ends thereof. Separate guide flanges are associated with each rectangular cut-out for positioning the template on the bench beam. The plate is formed with another cut-out that cooperates with some of the guide flanges for marking the leg boards for a cut to provide a wedge-lock t for the leg boards in bench beam. A pair of bracket-shaped cutting flanges, dening the rectangular cut-outs, extend from opposite faces, respectively, of the plate to mark the bench beam with initial cuts.

BACKGROUND OF INVENTION This invention relates to a novel template for marking mortise grooves in a bench beam for receiving leg boards for a carpenters trestle. The novel template is particularly useful for making an improved carpenters trestle by providing accurate markings on the bench beam for spacing, cutting, and angulating the mortise grooves, and on the leg boards for wedge-lock lits of the leg boards in the mortise grooves.

The construction of a good carpenters trestle, or carpenters horse as it is sometimes called, is usually a manual undertaking for an experienced carpenter. Unless the spacings, angles, and depths of the mortise grooves on the bench beam are correct, the resulting carpenters trestle will be unsteady and defective. It has been observed that many novice carpenters, and even some experienced ones, have diiculties in constructing stable sturdy carpenters trestles. The novel template of the present invention pro vides means for enabling almost anyone, regardless of his prior experience, to make an improved carpenters trestle with a minimum of effort and computation.

SUMMARY OF INVENTION Briefly stated, one embodiment of the novel template for marking mortise grooves in a bench beam comprises an elongated plate formed with a pair of rectangular cutouts of diierent depths in opposite sides, respectively, of the plate and intermediate opposite ends thereof. Separate guide means are associated with each of the cut-outs to position the template accurately on the bench beam for each mortise groove marking thereon. In another embodiment of the template, a pair of bracket-shaped cutting flanges define the aforementioned pair of rectangular cutouts and extend from opposite faces, respectively, of the plate for marking the bench beam with initial cuts. In still another embodiment of the template, at least one more cut-out is formed in the plate so that a linear portion of the plate that defines the latter cut-out cooperates with the guide means to mark the leg boards for cuts that will pro vide them with a wedge-shaped lit in the mortise grooves in the bench beam. At least one of the cutting flanges is formed with means to mark mortise grooves with either parallel sides or with non-parallel sides for a wedge-lock t of the leg boards therein.

3,529,361 Patented Sept. 22, 1970 ICC BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of one embodiment of the novel template;

FIG. 2 is a cross-sectional view of the template taken lalong the line 2-2 in FIG. 1 and viewed in the direction indicated by the arrows;

FIG. 3 is a cross-sectional view of the template taken along the line 3--3 in FIG. 1 and viewed in the direction indicated by the arrows;

FIG. 4 is a reduced top view of the template;

FIG. 5 is a reduced bottom view of the template;

FIG. 6 is a top View of a bench beam of a carpenters trestle showing top template markings thereon for mortise grooves;

FIG. 7 is a bottom view of the bench beam shown in FIG. 6 and illustrating bottom template markings thereon for the mortise grooves;

FIG. 8 is a fragmentary, perspective View of one end of a bench beam showing a mortise groove, cut pursuant to the novel templates markings, and a leg board received therein, a portion of the leg board being cut away to show details of the mortise groove;

FIG. 9 is a fragmentary, perspective view of another end of a bench beam showing mortise grooves, cut pursuant to the novel templatcs markings, for receiving leg boards therein with a wedge-lock fit;

FIG. 10 is a side elevational view of a carpenters trestle showing two leg boards received in mortise grooves in a bench beam, and (right) without a wedge-lock fit and the other (left) with a wedge-lock lit;

FIG. l1 is an end elevational view of the carpenters trestle shown in FIG. 10;

FIG. 12 is a reduced, fragmentary plan view of the novel template on a leg board for marking it for a cut for a wedge-lock t in a mortise groove; and

FIG. 13 is a fragmentary cross-sectional view of the novel template, taken along the line 13-13 in FIG. 1, showing slots in a cutting flange for marking mortise grooves for wedge-lock fits of leg boards to be received in the mortise grooves.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now particularly to FIGS. l, 2, 3, 4 and 5 of the drawing, there is shown a novel template 10 comprising an elongated plate 12 of metal formed with two rectangular cut- outs 14 and 16 in opposite parallel sides 18 and 20, respectively, of the plate 12, intermediate opposite ends 22 and 24 thereof. The plate 12 is made preferably of cast iron, but it may also be made of sheet metal or even a tough unbreakable-type plastic material.

The template 10 is adapted to provide means for marking a bench beam of a typical 24 inch high carpenters trestle. Thus, the template 10 is about 13 inches long and about 2 inches wide in its widest part. The plate 12 is divided into substantially three sections 26, 38 and 30 by the cut- outs 14 and 16. The relatively wider sections 26 and 30 are substantially similar and symmetrical to each other about a center (dashed) line 32 drawn perpendicular to, and substantially bisecting, a central longitudinal (dashed) axis 34 of the plate 12. The relatively thinner section 28 is about 5 inches long and about 1% inches wide. Each of the sections 2-6 and 30 is about 4 inches long and about 2 inches wide, except for rectangular cut- outs 36 and 38 in the ends 22 and 24, respectively, both adjacent the side 20. The depths of the rectangular cut- outs 14 and 16 are 5/8 inch and 1A inch from the sides 18 and 20, respectively. Each of the rectangular cut- outs 36 and 38 is about 3A; inch from its respective end. The dimensions of the template 10 are not critical and may vary in accordance with a particular mortise groove desired.

The upper face 40 of the plate 12, as shown in FIG. 1, should preferably be marked with indicia, such as TOP CUT and arrows pointing to the side 18a of the plate 12 that defines the cut-out 14, to indicate the positioning of the template 10 on the upper surface of the bench beam f for marking the depth of the mortise groove thereon. Likewise, the lower face 42 of the plate 12, as shown in FIG. 5, should also be marked with indicia, such as BOT- TOM CUT and arrows pointing to the side 20a of the plate 12 that defines the cut-out 16, to indicate the positioning of the template 10 on the lower surface of the bench beam for marking the depth of mortise groove thereon.

The template 10, as described thus far, may be used for spacing and marking mortise grooves in a bench beam 43, as shown in FIGS. 6 and 7. Thus, by positioning the template 10 first on the upper surface 45 of the bench beam 43, adjacent an end 24a thereof, so that one square corner 47 of the template 10, including the side 18 and end 24 of the section 30, for example, coincides with a square corner 47a of the upper surface 45 of the bench beam 43, and the edge 18 of the template 10 coincides with the edge 18b of the bench beam 43, the upper surface 45 of the bench beam 43 can be marked, as by bracket-shaped marking 45a, by running a pencil along the side 18a that defines the rectangular cut-out 14. Similarly, another bracket-shaped marking 45b for the mortise groove can be made adjacent the opposite end 22a of the bench beam 43 by aligning the square corner 49 of the template 10, including the side 18 of the section 26, with the upper square corner 49a of the bench beam 43 and running a pencil along the side 18a defining the rectangular cut-out 14. Bracket-shaped markings 45C and 45d, opposite markings 45a and 45b, respectively, are made in a similar manner.

The bracket- shaped markings 51a, 5117, 51C, and 51d for the depth and spacings of the mortise groove can be made by aligning the corners 53 and 5S of the template 10, including the side 20, with corresponding corners 53a, 55a, 5312 and 55b, respectively, of the lower surface 51 of the bench beam 43 and running a pencil along the side 20a defining the rectangular cut-out 16.

Although the template 10 may be used in the manner described above, its manipulation and accuracy can be improved by providing it with guide means for aligning it with the square corners of the bench beam 43. To this end, guide flanges 50 and 52 adjacent the side 18 of the section 30 extend perpendicularly and downwardly from the lower face 42 of the plate 12, and a guide flange 54, adapted to cooperate with the guide flanges 0 and 52, extends perpendicularly and downwardly from the lower face 42 adjacent the end 24. Thus, the top marking 45a, for example, for the mortise groove on the upper surface 45 of the bench beam 43, adjacent the end 24a thereof, can be marked accurately by engaging the square corner 47a of the bench beam 43 with the guide flanges 50, 52 and 54. The top marking 45b for the mortise groove on the opposite end 22a of the bench beam 43 can be marked accurately by engaging the square corner 49a of the bench beam 43 with guide flanges 56, 58 and 60, depending downwardly from the lower face 42 of the section 26. The bracket-shaped markings 45e and 45d opposite the markings 45a and 45h, respectively, are marked in a similar manner, with the template rotated 180 degrees in its plane.

Guide flanges are also provided for positioning the ternplate on the lower surface 51 of the bench beam 43 for accurately spacing and marking the mortise groove with respect to the side and ends of the bench beam. To this end, guide flanges 62 and 64 extend perpendicularly upwardly from the upper face 40, adjacent the side of the section 30, and a guide flange 66, adapted to cooperate with the guide flanges 60 and 62, extends perpendicularly and upwardly from the edge defining the cutout portion 38. A set of guide flanges 68, 70 and 72, substantially symmetrical disposed to the guide flanges 62,

4 64 and 66, respectively, extend upwardly and perpendicularly from the upper face 40 of the section 26 adjacent the sides 20 and 27, the latter side defining a portion of the cut-out 36.

In accordance with another embodiment of the present invention, means are provided in the template 10 to obviate the necessity of marking the spacings and depths of the mortise grooves with a pencil. To this end, means are provided to mark the spacings and depths of the mortise grooves with initial cuts. Thus, a bracket-shaped cutting flange '76 (FIGS. 2 and 13) extends perpendicularly and downwardly from the lower face 42 of the plate 12, adjacent the bracket-shaped side 18a that defines the rectangular cut-out 14. The cutting flange '76 comprises an inner wall 78 and an outer wall 80, and the cutting edge of the flange 76 is formed by a bevel edge 82, wherein the cutting edge 84 is provided by the inner wall 78 in cooperation with the bevel 82. With this arrangement, the cutting flange 76 can always be sharpened without changing the location of the cutting edge 84 with respect to the guide flanges 50, 52, 54, 56, 58 and 60. The guide flanges 50, 52, 54, 56, 58 and 60 extend further from the lower face v42 of the plate 12 than does the bracketshaped cutting flange 76.

A bracket-shaped cutting flange (FIGS. 1 and 2) substantially similar in construction to the cutting flange 76, except for the length of its short sides, extends perpendicularly upwardly from the upper face 40 of the plate 12, adjacent the bracket-shaped edge 20a that defines the rectangular cut-out 16. The bracket-shaped cutting flange 90 has an inner wall 92 that forms a cutting edge 94 with a bevel 96 that extends between an outer wall 98 and the inner wall 92, as shown in FIG. 2. The guide flanges 62, 64, 66, 68, 70 and 72 extend further from the upper face 40 of the plate 12 than does the bracket-shaped cutting flange 90.

' Means are provided to accurately position and to substantially fix the template 10 on the bench beam for marking it for the mortise groove. To this end, a pair of pins 100 and 102 (FIGS. 3 and 5) extend downwardly from lower face 42 of the sections 26 and 30, respectively, preferably for 'a distance greater than that of the bracket-shaped cutting flange 76 but less than that of the guide flanges 50, 52, 54, 56, 58 and 60. A substantially similar pair of pins 104 and 106 extend upwardly from the sections 26 and 30. The pins 100, 102, 104 and 106 serve to anchor the template 10 on the bench beam 43 by digging into the bench beam 43 when the template 10 is placed thereon, thereby preventing lateral movement of the template 10.

In operation, the template 10 is first aligned with the bench beam 43 by means of its guide flanges, as explained supra. The mortise groove markings (similar to the markings 45a, for example), are made by lightly tapping the center section 28 of the plate 12 with a hammer so that the cutting edge (e.g. 84) of the bracket-shaped cutting flange (e.g. 76) digs into the bench beam 43, thereby marking it with an initial cut for subsequent chiseling. During this marking operation, the pins 100 and 102 tend to-keep the template from moving laterally on the bench beam.

In still another embodiment of the present invention, the template 10 thus far described is provided with wedgelock marking means that cooperate with at least one set of guide flanges to mark the leg boards for the carpenters trestle with cuts that will provide them with wedge-lock fits in mortise grooves of the type provided by the novel template 10. The wedge-lock marking means comprise a right triangular cut-out in the section 30 of the plate 12. A straight edge 112 of the plate 12 that defines the hypotenuse of the triangular cut-out 110` forms an angle of about 13 degrees with the side 18. The straight edge 112 cooperates with the guide flanges 50, 52 and 54 to mark a leg board 113 (FIG. l2) whose squared corner is positioned between the guide flanges 50, 52, and S4.

When so positioned, the leg board 113 can be marked by running a pencil along the edge 112. When the marked corner of the end of the leg board is sawed olf, the end of the leg board 113 can be wedge-locked into the special mortise groove, hereinafter to be described, for a strong, steady, relatively non-slip joint, as shown by the left leg board 113 of the carpenters trestle 115 in FIG. 10. Another triangular cut-out 111, similar and symmetrical to the cut-out 110, is formed in the section 26 and adapted to cooperate with the guide anges 56, 58, and 60 for cutting an opposite corner from the leg board 113.

The bracket-shaped mortise markings 45a-45d`on the upper surface 45 on the bench beam 43, and their mating markings Sla-51d on the lower surface 51 of the bench ibeam 43 outline the positions, depths, and angulations of the mortise grooves to be chiseled, as illustrated by mortise groove 118 (FIG. 8) adjacent ton end 22a of the bench beam 43. The mortise groove 118 is a typical mortise groove with parallel sides for receiving a leg board 1.13 therein. When mortise grooves with parallel sides are used, the leg board 113 should iit snugly therein to provide a good, steady support for the trestle 115. A typical leg board 113 is usually a 1 x 6 inch board. These leg boards, however, have dimensions which vary over a relatively wide range so that leg boards provided by different suppliers may have different dimensions.

The novel template 10 has means for marking wedgereceiving mortise grooves for receiving boards 113, each with a sawed-off corner, wedged snugly therein even though the widths of the leg boards may vary somewhat. To this end, the cutting flange 76 is provided with means to mark one surface, usually the upper surface 45, of the bench beam with an indication for making a wedgereceiving groove with non parallel sides, as shown by the wedge-receiving mortise groove 12 (-FIG. 9) adjacent one end 24a of the bench beam 43. In the wedge-receiving mortise groove 120, its opposite sides 122 and 124 are not parallel so that the leg board 113, whose corner has been sawed olf, as explained supra, can be received therein in a wedge-lock t. The flange cutting flange 76 is formed with two narrow slots 126 and 128, as shown in FIG. 13. The slots 126 and i128 are spaced along the cutting ange 76 so that the provide small discontinuities, breaks 12611 and 128a (FIG. 6), respectively, in the mortise groove markings 45u-45d that indicate the (shortened) length of the top markings 45u-45d for the wedge-receiving mortise grooves. For example, to form the wedge-receiving mortise groove 120 (FIG. 9), the length of the mortise groove on the upper surface 45 of the bench beam 43 is extended only as far as the break 126a of the top marking 45C. The breaks 12611 and 128a are positioned to make the side 124 of the wedge-receiving mortise groove 120 substantially perpendicular to the upper and lower surfaces 45 and 51 of the bench beam 43. Thus, the non-parallel opposite sides 122 and 124 of the wedge-receiving mortise grooves 120 are disposed to receive a wedge-shaped board, such as the leg board i113 with its corner sawed off, snugly therein. The wedge-receiving mortise groove can snugly receive leg boards whose widths vary over a relatively wide range.

When the leg boards 113 are inserted into the mortise grooves in the bench fbeam 43 and nailed therein, as shown in FIG. l0, an apron board 130 is nailed across each pair of adjacent leg boards 113 to complete the carpenters trestle 115.

While there have been described herein a few embodiments of the novel mortise marking template, it will be understood that the combination of novel features and principles of this invention may be embodied in other specic forms without departing from the spirit thereof.

It is, therefore, desired that the present embodiments be considered merely illustrative of the present invention and not in a limiting sense.

What is claimed is:

1. A template for marking a mortise groove in a bench beam of rectangular cross-section for receiving a leg board for a carpenters trestle, said template comprising an elongated plate having upper and lower faces, a pair of opposite sides, and a pair of opposite ends,

a first rectangular cut-out formed in one of said opposite sides intermediate said opposite ends,

a second rectangular cut-out formed in the other of said opposite sides intermediate said opposite ends,

first guide means for positioning said template on one surface of said beam for marking it, and

second guide means for positioning said template on an opposite surface to said one surface of said beam for marking it,

said irst guide means comprising first guide anges extending downwardly from said lower face, adjacent said one side and said opposite ends, and said second guide means comprising second guide flanges extending upwardly from said upper face, adjacent said other side and said opposite ends,

a first bracket-shaped cutting flange deiining said iirst cut-out and extending downwardly from said lower face,

a second bracket-shaped cutting ange defining said second cut-out and extending upwardly from said upper face, each of said cutting ilanges having a cutting edge that lies a separate plane,

an opening in said plate adjacent said one side and one of said opposite ends,

a portion of said plate dening said opening comprising a straight edge disposed at an angle to said rst bracket-shaped cutting flange to cooperate with said iirst guide flanges for marking said leg board for a cut, whereby said leg board, when cut, provides a wedge-lock t in said mortise groove, and

one of said cutting flanges being formed with means to mark the length of the mortise groove along one surface of said bench beam for a mortise groove, either with substantially parallel sides to receive a leg board with parallel sides, or with non-parallel sides for a wedge-lock t of a leg board having nonparallel sides adjacent an end thereof.

2. A template as described in claim 1 wherein said means to mark the length of the mortise groove along one surface of said bench beam comprises at least one slot in said rst bracket-shaped cutting ange.

References Cited UNITED STATES PATENTS 2,927,378 3/1960 Godfrey 33-197 3,184,859 5/1965 Patrick 33 197 3,222,792. 12/1965 Eshom. 3,435,531 4/1969 Morris.

FOREIGN PATENTS 19,330 4/1929 Australia.

LEONARD FORMAN, Primary Examiner D. A. DEARING, Assistant Examiner U.S. Cl. X.R. 33-197

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