US3035618A - Template for mortising doors and jambs for application of hinges - Google Patents

Description

May 22, 1962 a. J. MEN KE 3,035,618 TEMPLATE FOR MORTISING DOORS AND JAMES FOR APPLICATION OF HINGES Filed Jan. 26, 1960 3 Sheets-Sheet 1 INVENTOR.

BENJAMIN Jv MENKE ATTORNEYS May 22, 1962 B. J. MENKE 3,035,613

TEMPLATE FOR MORTISING DOORS AND JAMES FOR APPLICATION OF HINGES Filed Jan. 26, 1960 3 Sheets-Sheet 2 INVENTOR. BENJAMIN J. MENKE ATTORNEYS May 22, 19 2 B. J. MENKE 3,035,618 TEMPLATE FOR MORTISING DOORS AND JAMES FOR APPLICATION OF HINGES Filed Jan. 26, 1960 5 Sheets-Sheet 3 I 1 I96 I 1a 50 I 194 5 BENJAMIN J. MEN KE ATTORNEYS United States Patent 9 3,035,618 TED [PLATE FOR NIORTISING DOORS AND JANIBS FOR APPLICATION OF IHNGES Benjamin J. Menke, 619 Van Nostrand Place, Eigin, Ill. Filed Jan. 26, 1960, Ser. No. 4,772 4 Claims. (Cl. 144-27) My invention relates to a template for mortising doors and jarnbs for application thereto of hinges, and more particularly, to a template arrangement for properly locating, on doors and jambs, the portions thereof that are to be mortised to receive a hinge leaf.

Conventionally, carpenters, cabinet makers, and others concerned with hinging doors to jambs having to lay out on a door or jamb the portion thereof which is to be mortised to receive a hinge leaf for purposes of hinging a door to a jamb. The portion to be mortised is usually marked in pencil and made the siZe adapted to receive the hinge leaf in question, which means that the hinge leaf mortise not only has to be accurately marked out on the door or jamb, but also properly located with regard to the mortise that is to receive the companion hinge leaf. Thus, much time and effort is necessarily consumed in layout work, which materially increases the time required to hinge doors.

It is the principal object of this invention to provide a template arrangement which eliminates the need for marking the door or jamb portions to be mortised, and which may be used to automatically properly index the door and jamb portions that are to be mortised to receive companion hinge leaves of a hinge unit.

Another object of the invention is to provide a template for guiding routers, which is especially adapted for mortising door edges and jambs to receive hinge leaf elements.

Still another object of the invention is to provide a door hinge leaf mortising template device which is inexpensive of manufacture, convenient in use and adapted for application to a wide variety of door hing'ng problems.

Other objects, uses and advantages will be obvious from a consideration of the following detailed description and the application drawings.

In the drawings:

FIGURE 1 is a frontal perspective view of a preferred form of invention, on an enlarged scale;

FIGURE 2 is a rear elevational view of the device shown in FIGURE 1, on a somewhat smaller scale;

FIGURE 2a is a plan view of a removable fence forming a part of the illustrated embodiment;

FIGURE 3 is a bottom plan view of the structure shown in FIGURE 2, partially in section and showing a door edge in outline form;

FIGURE 4 is a diagrammatic perspective View, illustr-ating a mortised portion of a door jamb which may be defined by the template arrangement of my invention;

FIGURE 5 shows my invention applied to the door jamb of FIGURE 4 to define the jamb portion thereof to be mortised;

FIGURE 6 is a diagrammatic perspective view of the door edge mortised portion that may be defined by my template arrangement;

FIGURE 7 is an elevational view of the door edge shown in FIGURE 6 showing my invention applied thereto to define the mortised portion thereof, with the door being shown in outline;

FIGURE 8 is an elevational view of an indexing rod associated with my template arrangement;

FIGURE 9 is a diagrammatic sectional view illustrating a latch device that is employed for associating the indexing rod with my template arrangement;

FIGURE 10 is a diagrammatic perspective view of a "ice latch device for insuring that my template is clamped in place for mortising purposes;

FIGURE 11 is a diagrammatic perspective view illustrating a door edge having a door lock mortised portion that may be defined by employing my template arrangement;

FIGURE 12 is a small scale elevational view illustrating the manner in which my template arrangement may be employed to define the mortised portion of FIGURE 11, showing special adapter elements that are provided to define the door lock mortise;

FIGURE 12a is a side elevational view of one of the adapter elements shown in FIGURE 12; and

FIGURE 13 is a diagrammatic perspective view illustrating the manner in which my invention is employed to mortise rabbetted jambs.

General Description Reference numeral 10 of FIGURE 1 generally indicates a preferred embodiment of my invention which comprises a frame 12 fixedly carrying track forming members 14 and 16 which slidably mount opposed jaws 18 and 20 that are to define the area of the door jamb or door edge which is to be mortisedi The jaws 18 and 20 are located on the forward side of the frame 12; at the rearward side of the frame 12 are slidably mounted a rigid abutment forming member 22 (see FIGURE 2) and a detachable fence 24, which is coextensive with the rigid abutment forming member 22. A clamping foot 26 is fixed to the end of a rack 28 slidably secured to the frame for operation in the plane of abutment forming member 22.

In the illustrated form of the invention, the frame includes spaced bracing members 30 that extend crosswise of the track forming members 14 ant 16 and have applied thereto measuring indicia where indicated at 32 (see FIG- URE 2), the zero dimension commencing at the face 34 of track forming member 16. The measuring indicia 32 extend between the two track forming members and may be calibrated in inches -or any other standard of measurement.

The device 10 has associated therewith an indexing rod (see FIGURES 1 and 8), which as indicated in FIG- URE l, is slidably received in aligned openings 42 formed in frame members 30 and is engaged by a suitable latch device 44 for holding the template frame in desired positions of adjustment with respect to the indexing rod. The indexing rod 40 is formed with the spaced annular grooves marked 1-8 in FIGURE 8 and when the latch device 44 is applied to one of the grooves as indicated in FIGURE 9, the template frame will be properly located to define a door edge or j amb portion to be mortised.

The device also includes the special adapter members 46 of FIGURE 12 for adapting the template to form door lock face plate mortises.

Specific Description Referring now to the specific structure illustrated, frame 12 comprises spaced framing members 50 which are horizontally disposed when the device 10 is applied to a door edge or the like, and which are rigidly fixed together by spaced crosswise extending framing members 52, 54 and 54a, member 54a be ng fixed at its center to spaced framing members that are secured between member 52 and the adjacent track forming member 16. Members 52, 54, 54a and 55 may be fixed together in any suitable manner, as by screws 56. The members 54 and 54a are each formed with an upstanding flange 58 between which are fixed the track bracing members 30, the latter being notched as at 60 to receive the track forming members 14 and 16 and their slidably mounted jaws 18. The track forming members 14 and 16 may be fixed to framing members 50 in any suitable manner, as by welding or suitable screws or press fitting, etc. As indicated in FIGURES 1 and 2, track forming members 14 and 16 are formed to define slots or grooves 62 that slidably engage flanges 64 of jaws 18 and 20.

Jaws 18 and 20 in the illustrated embodiment each comprise a plate-like member 66 having fixed to the front portion thereof an angle member 68. Angle member 68 has a flange 70 fixed to the respective jaws by appropriate screws 72- and a depending flange 74 that together with the inner surfaces 34 and 35 (see FIGURE 2) of the track forming members define the perimeter of the mortising opening formed by device 11 It will be noted that this opening is a substantially closed perimeter opening and that the surfaces 34 and 35 of the track forming members as Well as surfaces 76 of the jaws are of substantially equal depths (see FIGURE 3). Track forming members 14 and 16 each include relatively wide center portions 78 (see FIGURE 1) to define the surfaces 34 and 35. 7

As best seen in FIGURE 1, the jaws 18 and 20 are each formed with an elongate slot 80, each of which is formed with spaced countersinkin chamfers 82 which preferably are spaced a measured distance apart and in a preferred form are struck on centers inch apart.

Chamfers 82 are provided to countersink indexing screws 84 that are received in slots 80 and the respective bracing members 31) for purposes of locking the jaws 13 and 20 in desired positions of adjustment.

At the rearward side of the device 10, the rigid abutment forming member 22 comprises in the illustrated embodiment an elongate bar 90 fixed at its ends, as by screws 91, to blocks 92 which are slidably received over the respective frame members 50 and carry set screws 94 for locking them into fixed relation with frame. The rigid abutment forming member 22 is recessed along its center portion as at 6 to define a channel shaped configuration that provides clearance outside of the door for the router blade to operate in and thus defines coplanar abutment surfaces 9-8 at each end of the member 22 or in the projections defined by the channel shaped configuration.

The fence 24 comprises a bar-like member 100 having its ends suitably notched as at 102 for reception over the framing members 50 and carrying set screws 104 that are to engage the respective frame members 50 to fix the fence member 100 in a desired position of adjustment. The center portion 101 of the member 100 is disposed at one side of the fence (see FIGURE 2a) so that when it is applied to the frame 12, it provides adequate operating clearance for the router blade.

The rack 28 has foot 26 fixed thereto as by appropriate screws 110, and foot 26 is disposed in the plane of abutment forming member 22 (see FIGURE 3). The rack 28 is slidably secured to the frame 12 between framing members 55 in any suitable manner, as by being applied between plates 112 and angle members 114 on one side of member 52 (see FIGURE which are secured together by appropriate rivets or screws 119; on the other side of member 52, the rack 28 is applied between angle members 116 and 117, which are secured together by similar screws 119.

As shown in FIGURE 10, the rack 28 has formed on its outwardly facing surface with teeth 118 which are engaged by a pawl 121 pivoted to latch arm 122 as at 124. Latch arm 122 in the illustrated embodiment is pivoted between spaced upstanding flanges 126 of the respective angle members 116. A U-shaped spring guard 128, comprising a spring wire having its ends 130 fixed to the edges 132 of the respective angle members 114 acts as a retainer for pawl 12%. Obviously, when the pawl 120 is applied to teeth 118 and latch arm 122 pressed downwardly to dispose pin 124 below pin 126, the foot Will be locked in operating position.

The latch 44 that cooperates with indexing rod 40 in the illustrated form comprises a tubular block 132 fixed to the track forming member 16 in any suitable manner, as by appropriate screws 133 (see FIGURE 2). The tubular housing is proportioned to slidably receive rod 48 in its bore 134 (see FIGURE 9) and pivotally carries latch arm 136. Latch arm 136 may include flanges 138 through which pin 140 extends to pivot same to appropriate flanges 142 fixed to the member 132. The latch arm 136 includes a suitable spring 144 (see FIGURE 9) for biasing the notched end 146 thereof into engagement with indexing rod 40. The notched end 146 is formed with a semicircular groove 148 that is complementary to the respective annular grooves 1-8 of FIG- URE 8.

The special adapter members 46 of FIGURE 12 generally comprise plate- like members 150 and 150a having fixed thereto along one edge the spaced pairs of lugs 152 and 154, as by appropriate screws 156. The inner pair of lugs 154 may be integrally united to a connecting bar 153, and the outer lugs carry set screws for engagement with the frame members 50 when the latter are received between the lugs of the respective pairs of lugs 152 and 154. The adapter members 46 are of substantially identical construction, but the lugs 152 and 154 are applied to opposite edges thereof, as indicated in FIGURE 12. The adapter members 46 are applied to the device 10 with their plate-like members 150 and 15011 overlying the jaws 18 and 20, and preferably the jaws 18 and 20 are formed with measuring indicia where indicated at 162 so that the planar edges 164 of the members 46 may be properly spaced from each other and from the inner surfaces of track forming members 14 and 16.

Rod 40 ordinarily will be supplied in disconnectable sections and may assume various standard lengths, de-

" pending upon the operation to which the invention is to be applied. For instance, it may be assumed that the device 10 isto be used for hinging door heights of 7 feet and 6 feet 8 inches. Consequently, rod 40' Would therefore have a corresponding length and the annular grooves l-8 are provided for mortising the following (all measuring from the top of the door or jamb, as the case may be): For doors and jambs 7 feet in height, the annular grooves marked 1 will locate the frame 12 for mortising for the top hinge leaves of the door While the annular grooves 2 will locate the frame 12 for mortising for the bottom hinge leaves; the annular grooves marked 6 Will locate the frame 12 for mortising for the center hinges (assuming the standard hinging arrangement of three vertically spaced pairs of hinges), while the annular grooves 7 will locate the frame 12 for mortising the door lock recess and strike plate recess in the jamb shown in FIG- URE 11. The annular grooves 8 are provided for mortising rabbeted jambs, as hereinafter described more spe cifically.

In the embodiment illustrated, rod 40 may be also employed for mortising 6'foot 8 inch doors and jambs. Thus, the grooves 1 may be used to locate the frame 12 for mortising the top and bottom hinge leaf recesses, while the annular groove 3 may be employed to mortise for the center hinge leaf recesses; groove 4 will locate the frame 12 for mortising the door lock openings and the corresponding strike plate mortises in the jamb While annular recesses 8 are again especially adapted for use with rabbeted jambs.

Rod 49 in its illustrated form has the notches 2-8 symmetrically disposed on either side of the center notch 3 so that either end of the rod 40 may be used with equal facility.

In accordance with this invention, the rod 40 has secured to each end thereof, as by appropriate screw 180, a foot 182 which forms an abutment member for the end of the rod 41}. The foot 182 preferably includes a pointed arm 184 that may be driven into the jamb to support frame 12, When frame 12 is applied to a jamb, as hereinafter described, and a. laterally directed seating flange 185.

Manner of Using Invention When employing the device to mortised door edges and jambs to receive hinges, the special adapter members 46 are left oft", while the abutment forming members 22 and fence 24 are applied to the positions best shown in FIGURES 2 and 3.

The jaws 18 and 20 are then positioned as about to be described to conform to the size of the hinge leaf of the hinge unit for which the mortising operation is to be performed. As the surface 34 of track member 16 starts the zero measurement of scales 32, the hinge is placed within the mortising opening 25 and against the surface 34, after which the respective screws 84 are loosened to permit the jaws 1'8 and 20 to be set against the hinge ends and preferably an equal distance on either side of a center position marked by the spaced lines 170 (see FIG- URE 1) on the outwardly facing surfaces 171 of the track forming members 14 and 16. Alternately, one may appropriately space jaws 18 and 20 by measuring one half the hinge leaf length from center notching lines 170.

The surface 172 (see FIGURE 2) of the fence 24 is then set at the point on scales 32 which indicates the width of the hinge leaf for which the mortising operation is required. Set screws 104 of the fence are then set against frame members 59 to lock it in position and rigid abutment forming member 22 is drawn up against the fence 24 and fixed in place by its set screws 94. Abutment forming member 22 acts as a backstop for fence 24.

Rod 40 may then be applied to its mounting body 132, which is done by inserting a section of same through body 132 and the aligned openings 42 of bracing members 30.

When rod 40 has been applied to latching device 44, the latch arm 136 is applied to the appropriate annular groove of rod 40 to dispose the frame 12 in the desired position to locate a hinge leaf recess, for instance, the hinge leaf recess 190 of FIGURE 6, shown formed in edge 192 of door 194. It may be assumed that the door 194 is a 7 foot door and that recess 190 is for the top hinge, and thus annular groove 1 would be engaged by latch arm 136 to properly position the frame 12 with re spect to the door. The outwardly extending end 195 of foot 182 of rod 40 then may be applied over the top 196 of the door to temporarily suspend the frame from the top of the door, with the rearward side of the frame being placed in abutting relation with the edge 192 of the door and between the fence 24 and foot 26, with the door side surface 198 abutting against surface 172 of fence 24. Rack member 28 is then moved in the direction of the door to bring foot 26 into engagement with the other side surface of the door, after which the latching device of FIGURE 10 is operated to clamp the door between foot 26 and fence 24.

The template is now in position for routing out of the hinge recess, and this may be done by a suitable router applied to the mortising opening 25 defined by the jaws 18 and 20 and track forming members 14 and 16.

When the corresponding hinge leaf recess of the door jamb is to be formed, the template is removed from the door and then the foot 182 of the rod 40 is placed in engagement with the undersurface 200 of the door frame header member 202, as indicated in FIGURE 5, with the pointed arm 184 beating against the jamb and flange 185 at right angles to the jamb; the frame 12 may be temporarily suspended in position by tapping the edge 187 of flange 182 to drive arm 184 into the jamb. Of course, the edge 204 of the jamb 206 must be placed in engagement with the surface 172 of the fence 24 and then foot 26 applied to edge 208 as before described. The hinge recess 210 of the door jamb may then be routed out by applying a suitable router to the jamb.

It will be apparent that the center and bottom hinge mortises may be formed by employing the device 10 in a similar manner, rod 40 being employed to measure all distances from the door header. The center hinge mortises can be formed by indexing the frame 12 from either the top or the bottom of the doorway.

In the instance where the hinge is to be applied to a rabbeted jamb, as in the showing of FIGURE 13, the frame 12 is set at the number 8 groove to define the upper and center hinge mortising areas, and then the foot 182 is placed in engagement with the lower surface 220 of header member 222. The device is then operated as before described to locate and rout out the recess for the hinge. The location of the corresponding hinge on the door edge is made by moving the frame 12 down to the adjacent groove 1 and then proceeding as before described.

It may be mentioned that the need for groove 8 is necessitated by the recess 224 which is formed in the edge of rabbeted jamb 226 and gives the jamb its name. The recess 224 complements like recesses 227 formed in the header member and opposing jamb to recess the door within the door frame when the door is in its closed position. This arrangement is frequently found at the exterior side of dwelling entrances. Thus, groove 8 of rod 40 is spaced from groove 1 a distance corresponding to the depth of recess 227 of the header.

Door lock openings, such as that shown at 230 in FIGURE 11, may be properly located by applying the adapter devices 46 to the frame 12 in the manner indicated in FIGURE 12 and spacing them as indicated by the scales 1 62, after which set screws 160 are tightened against the respective track bracing members 30. The zero reading of these scales commences at surface 34 of track forming member 16 which may be set at the edge of the door by setting fence 24 to the door thickness on scales 32, and since door lock openings 230 are normally centered with respect to the thickness of the door 232, the edges 164 of adapter members 46 may be appropriately spaced from each other and from surface 34 (to define the side edges of the lock mortise) by considering the Width of the door lock opening 230 and the distance that its sides 234 are to be spaced from the side surfaces 236 of the door. Jaws 18 and 20 are set to define the upper and lower edges of the lock mortise.

Another way of locating the door lock mortise is to set jaws 18 and 20 as above indicated and to set the fence 24 on scales 32 at a distance equivalent to the width of the door lock mortise required plus its spacing from the sides of the door. When the frame 12 is applied to the door, this automatically locates surface 34 at one side edge of the desired door mortise, and the other side edge may be located by setting edge 164 of member a from surface 34 a distance equal to the width of the door mortise. In this instance, member 150 is disposed to the right of surface 34 in the showing of FIGURE 12, but aids in providing a level support for the routing tool, as members 150 and 15th; are of equal thicknesses (the tool base resting on or being pressed against members 150 and 150a during operation of same). Another reason for using the device in this manner is that member 150 is positioned out of the Way of lock 44, which permits an indexing rod location change without having to change the positioning of members 150 and 150a.

Member 151) in the illustrated embodiment is made sufficiently narrow so that its edge 164 may be set back of surface 34 (to the right of FEGURE 12).

The mortises for lock bolt strike plates may be located by using the same fence setting made for the door lock mortise, removing members 150 and 150a and applying frame 12 to the jamb at the same setting on index rod 40.

The indexing rod 40 may be employed to properly locate frame 12 for forming the door lock mortise, and in the case of the illustrated embodiment, frame 12 is set at either of grooves number 7 and 4, depending on the door height (measuring from the top of the door).

I have found that fence 24 may be employed with device in all instances of use except when applying the device to cased jambs with 4 inch recessed margins and that when used, its depth increases the'bracing action provided. In the instance of said cased jambs, the fence 24 should be removed from the device, and the surfaces 98 (see FIGURE 2) of abutment forming member 22 employed to clamp frame 12 in place on the jamb.

It will therefore be appreciated that I have provided a template device for mortising doors and jambs which materially facilitates the installation of doors. The device completely eliminates the need for laying out hinge locations on doors and jambs and in effect puts the mortising operation on a mass production basis. The device may be set to locate standard hinge positions and rapidly applied to and removed from doors and jambs during the mortising process. The arrangement of the device is such that after the hinge leaves have been applied, and assembled by the usual pivot, the door will be true with its opening.

The disclosed devicecan be used for mortising hinges from sizes 1 inch to 5 inch or doors of from inch to 2%. inch in thickness and jambs of from 1 inch to 5% inch in width. In addition to the aforementioned uses, the device may be used to mortise for flush stay bolts in doors.

The foregoing description and the drawings are given merely to explain and illustrate my invention and'the invention is not to be limited thereto, except insofar as :he appendedclaims are so limited, since those skilled in the art who have my disclosure before them will be able ;0 make modifications and variations therein without departing from the scope of the invention.

Iclaim:

1. A template for guiding a routing tool while mori-ising doors and jambs to receive hinges, said template :omprising a frame defined by two spaced apart frame members secured together by spaced apart crosswise ex- .ending members, a pair of track forming members sezured in parallel relation'between the two first menioned members, a pair of opposed jaws slidably mount- :d between said track forming members, whereby said aws and said track forming members define a closed :erimeter mortising opening, said jaws and said track orming members presenting planar unbroken guiding urfaces of substantially equivalent depths about the permeter of said opening, said jaws being at the forward ide of said frame and comprising plate-like members hat extend oppositely of each other and away from said )pening, said plate-like members of said jaws each beng formed with a slot extending parallel to the path of movement of said jaws, said slots each having spaced ountersinking chamfers formed therealong, screw means arried by said frame in association with each jaw slot or engaging in the respective countersinking chamfers o fix said jaws in desired spaced relation, means for lamping said frame against a surface to be mortised /ith the rearward side of said frame abutting said surace, said clamping means comprising an elongate rigid iember adjustably secured to the rearward side of said tame for movement transversely of said track forming lembers, a clamping foot adjustably secured to the rearard side of said frame and movable transversely of said ack forming members and toward and away from said .gid member, said rigid member being disposed between aid track forming members and said foot being disosed to one side of said track forming members and djacent one of said track forming members, said foot nd said rigid member being in coplanar relation in a lane that is parallel to the plane of said frame and dening abutment surfaces extending parallel to said track )rming members and normally of the plane of said frame,

latch device for clamping said foot against a door or Lmb applied between said surfaces of said foot and lid rigid member, means for releasably securing said gid member in a desired position of adjustment between lid. track forming members, and measuring indicia applied to said frame between said track forming members and commencing with zero measurement at said one of said track forming members. i

2. The template set forth in claim 1 wherein said frame slidably receives an indexing rod that extends crosswise thereof, said rod being formed with indicia means for locking the template with respect to a door or jamb to mortise same, wherein said frame includes means for releasably latching said template to said rod at said indicia means, and wherein said rod includes a laterally extending foot for placement adjacent the end of a door or jamb to index said frame with respect to the door or jamb, said foot of said indexing rod including a pointed finger adapted to be driven into a jamb to suspend said frame in indexed position.

3. A template for guiding a routing tool while mortising doors and jambs to receive hinges, said template comprising a generally planar frame, a pair of track forming members secured in parallel relation to said frame, a pair of opposed jaws slidably mounted between said track forming members, whereby said jaws and said track forming member define a closed perimeter mortising opening, said jaws and said track forming members presenting planar unbroken guiding surfaces of substantially equivalent depths about the perimeter of said opening, means associated with the front side of the frame for adjustably securing said jaws in desired spaced relation,

means for clamping said frame against a surface to be mortised with the rearward side of saidframe abutting said surface, said clamping means comprising an elongate rigid member adjustably secured to the rearward side of said frame for movement transversely of said track forming members, a clamping foot adjustably secured to the rearward side of said frame and movable transversely of said track forming members and toward and away from said rigid member, said rigid member being disposed between said track forming members and said foot being disposed to one side of said track forming members and adjacent one of said track forming members, said foot and said rigid member being in coplanar relation in a plane that is parallel to the plane of said frame and defining abutment surfaces extending parallel to said track forming members and normally of the plane of said frame, said rigid member comprisingtan elongate element defining a channel shaped configuration with its abutment surfaces being formed in the projections of said channel shaped configuration, said abutment surfaces of said rigid member being in coplanar relation, a latch device for clamping said foot against a door or jamb applied between said surfaces of said foot and said n'gid member, means for releasably securing said rigid member in a desired position of adjustment between said track forming members, and measuring indicia applied to said frame between said track forming members and commencing with zero measurement at said one of said track forming members.

4. The template set forth in claim 3 wherein a removable fence is slidably secured to said frame between said foot and said rigid member, said fence'projecting rearwardly of said rigid member and comprising a planar element of channel shaped configuration having the projections defined by said channel shaped configuration slidably secured to said frame, said fence increasing the stability of the clamping action provided by said foot.

References Cited in the file of this patent UNITED STATES PATENTS 636,661 Guest Nov. 7, 1899 1,524,234 Carter Jan. 27, 1925 1,679,074 Carter July 31, 1928 1,788,256 Sherwin Jan. 6, 1931 2,629,937 Tubbs Mar. 3, 1953 2,660,803 Sacrey Dec. 1, 1953 2,674,280 Pierce Apr. 6, 1954

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