US3713217A

US3713217A - Door latch cut-out forming

Info

Publication number: US3713217A
Authority: US
Inventors: C Frederick; H Woodrum
Original assignee: American Standard Inc
Current assignee: Trane US Inc
Priority date: 1971-04-26
Filing date: 1971-04-26
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30

Abstract

A method and apparatus for forming a cut-out in the edge of a metal door for reception of various size mortise lock latches. The method and apparatus are particularly conceived for employment at the job site or at the local door distribution point, such that the door distributor is able to stock relatively few standard doors (without latch cut-outs) instead of a larger number of similar doors having special size latch cut-outs.

Description

United States Patent [19] Frederick, Jr. et al.

11 3,713,217 1 Jan. 30,1973

[54] DOOR LATCH CUT-OUT FORMING [75] Inventors: Claud Frederick, Jr., Cincinnati; Harold L. Woodrum, Westchester, both of Ohio [73] Assignee: American Standard Inc., New York,

[22] Filed: April 26, 1971 [21] Appl. No.: 137,249

[52] US. Cl. ..30/287, 143/43, 83/54, 144/309 [51] Int. Cl. ..B26d 3/08 [58] Field of Search ..83/54, 560, 559',143/43 R, 143/43 A, 43 N; 30/286, 289, 292, 293, 294, 287; 144/309 [56] References Cited UNITED STATES PATENTS- Gragg ..30/293 X 1/196] Harian ..30/292X 5/1972 Baechle ..l43/43A Primary ExaminerAndrew R. Juhasz Assislant,Examiner--W. D. Bray Attorney-John E. McRae, Tennes l. Erstad and Robert G. Crooks 1 ABSTRACT A method and apparatus for forming a cut-out in the edge of a metal door for reception of various size mortise lock latches. The method and apparatus are particularly conceived for employment at the job site or at the local door distribution point, such that the door distributor is able to stock relatively few standard doors (without latch cut-outs) instead of a larger number of similar doors having special size latch cutouts.

5 Claims, 9 Drawing Figures PAImIEumsoma 3.713.217

sum 1 OF 2 Pic-2.9

' INVENTORS CLAUD FREDERICK,UR HARDLB L WoanRu DOOR LATCH CUT-OUT FORMING THE DRAWINGS FIG. 1 is a perspective view showing the edge of a metal door having an apparatus of this invention mounted thereon.

FIG. 2 is a view similar to FIG. 1 with a portion of the apparatus removed.

FIGS. 3 and 4 are longitudinal cross sectional views of the FIG. 1 apparatus.

FIG. 5 is a sectional view on line 55 in FIG. 4.

FIG. 6 is a reduced scale view of the FIG. 1 apparatus with a part thereof removed to illustrate a drilling step employed in the method of this invention.

FIG. 7 is an enlarged transverse sectional view on line 7-7in FIG.5.

FIG. 8 is an enlarged fragmentary view in the direction of arrow 8 in FIG. 7.

FIG. 9 is an enlarged fragmentary view on line 9-9 in FIG. 2.

GENERAL CONCEPT This invention contemplates a method and apparatus for field-formation of rectangular cut-outs in the edge areas of metal doors. The apparatus is designed so that the length and width of the cut-out can be varied to accommodate various sizes and types of mortise lock latches installed in the field.

An illustrative apparatus of this invention includes a base or guide structure clampable on the edge of a metal door to guide a saw blade carrier for movement in planes paralleling the face of the door. The saw blade carrier mounts a saw blade assembly which comprises two rotary saw blades affixed to a single drive shaft connectable to a conventional power drill. When the drill and saw blade carrier are manually moved toward the edge of the door the rotating saw blades form two parallel slots in the door edge; thereafter the saw blade carrier can be manually shifted along the guide structure to cause the saw blades to increase the lengths of the slots.

The clampable guide structure includes a rectangular opening whose end edges define straight edge surfaces for scoring or scribing bend lines between the ends of the saw-formed parallel slots; this arrangement enables the door material between the slots to be bent back and forth about the score lines to sever the door material and form a rectangular cut-out.

CLAMPABLE GUIDE STRUCTURE CONSTRUCTION As shown in FIG. 1, the clampable guide structure comprises a channel-like base 10 having a web wall 12 and two

flange walls

14 and 16 overlying the faces of a metallic door 17. FIG. 7 illustrates the door as having sheet metal faces 18 and 20 interconnected by an edgeforming wall structure 22.

Guide structure 10 may be clamped in a selected location on the edge of the door by means of two clamping screws 24 shown best in FIGS. 5 and 7. These screws are threaded into suitable nuts 26 carried by guide wall 16, so that manual rotation of each screw causes the screw to move a leaf spring 28 into clamping engagement with the door. As shown in FIG. 5, the leaf spring 28 extends the full length of guide member l0 and is secured at its midpoint to guide member flange 16 by rivets 30, such that the spring exerts a reaction force to prevent screws 24 from working out of nuts 26 during non-use periods. In use, the clampable guide structure 10 is positioned over the edge of the door, and the screws 24 are then tightened to bring spring 28 into clamping engagement with face 17 of the door. The other face of the door is engaged by an anti-scuff pad 31 carried by flange wall 14 (see FIG. 7). The contact areas of spring 28 on the door face are relatively large; hence the springs serve as flexible bearing pads to prevent marring of the door surface when screws 24 are tightened.

As shown in FIG. 6, web wall 12 of guide structure 10 is provided with a rectangular opening 23 which forms

end edges

19 and 21, and

side edges

25 and 27. When structure 10 is clamped on the edge of the door the opening 23 provides space for drilling a circular hole 29 into the edge of the door. Opening 23 also permits parallel saw cuts to be formed in the edge of the door, as will be hereinafter apparent.

SAW CARRIER CONSTRUCTION As shown in FIG. 1 the saw carrier 36 comprises a box-like housing having atop wall 38,

side walls

40 and 42, and

end walls

44 and 46.

Side walls

40 and 42 extend downwardly further than

end walls

44 and 46 so that when the lower edges of

walls

44 and 46 rest on the face of guide wall 12 (as shown in FIG. 4)

walls

40 and 42 closely overlap

walls

14 and 16 of guide structure 10.

Walls

40 and 42 are spaced from one another by a distance which corresponds to the width of guide 10 as defined by

walls

14 and 16. This overlapping relationship confines housing 36 to movement in a single plane as it is moved longitudinally in the arrow 400 direction (FIG. 4). The wall overlapment relationship also provides guidance for the saw carrier as it is tiltably moved toward the edge of door 17, in the manner illustrated in FIG. 3.

SAW ASSEMBLY FIG. 7 shows a saw assembly which comprises a multipiece drive shaft rotatably positioned in

nylon bearings

52 and 54. The shaft comprises a first threaded shaft element 56 rigidly affixed to a shoulderforming nut 59, a second threaded shaft element 58 rigidly affixed to a shoulder-forming nut 62, and a spacer block 64 removably threadably connected to both shaft elements. Two

circular saw blades

66 and 68 are positioned on the shaft elements before the elements are threaded into block 64. Auxiliary spacer discs in the form of washers 70 may be strung on the RETENTION OF THE SAW ASSEMBLY IN CARRIER 36

Carrier side walls

40 and 42 are formed with indentations or slots 43. When carrier 36 is removed from guide and turned upside down it is possible to position the saw assembly within the carrier housing such that bearings 52 and 53 fit through slots 43 with their shoulder surfaces 57 (FIG. 7) frictionally gripping

walls

40 and 42; the shaft-saw unit rotates in the bearings.

Inadvertant displacement of the saw assembly out of carrier 36 is prevented by two wire retainers 55, one of which is shown in FIG. 8. One end of each wire is looped around a headed post (rivet or screw) 61. The other end portion of the wire is of V-shaped configuration (as at 63) for manual retention on a second headed post 65. The free end 67 of the wire acts as a handle to permit manipulation of the wire onto and off of post 65 In the FIG. 8 position the wire underlies the projecting portion of the bearing to retain the saw assembly in carrier 36. When the wires are looped off of the respective posts 65 the saw assembly can be removed from carrier 36.

MODE OF OPERATION Initially guide 10 is clamped on one of the longitudinal edges of a metal door at a selected location intermediate the door upper and lower edges. The guide location is chosen so that rectangular opening 23 in guide wall 12 is spaced the predetermined distance from the door lower edge which will result in the correct position of the door lock. For example, with most doors the lock would be about three feet four inches from the door lower edge.

With guide 10 suitably clamped on the edge of the door, a small circular hole 29 is drilled through the door edge wall 22, as shown in FIGS. 6 and 7. The diameter of hole 29 is chosen to be somewhat less than the width of opening 23 and the spacing of

saw blades

66 and 68. For example, if opening 23 is 1 31; inches then hole 29 might be about 1 inch in diameter. In any event, hole 29 should be drilled centrally with respect to the

lateral edges

25 and 27 of opening 23 so that hole 29 is between the slots subsequently formed by

saw blades

66 and 68, as shown in FIG. 7.

After formation of hole 29 the saw assembly is locked in carrier 36 (using retainers 55) and shaft element 56 is chucked into power drill 61. The workman grasps the drill in one hand and handle 37 in the other hand; he then positions carrier 36 in a tilted position on guide 10, as shown in FIG. 3. Handle 37 is used to manually tilt carrier 36 downwardly from the FIG. 3 position to the FIG. 4 position. During this downward tilting motion the

flanges

40 and 42 of the carrier lie closely alongside the outer surfaces of the

guide walls

14 and 16 so that the carrier is restricted to movement in a vertical plane i.e. parallel to the

faces

18 and 20 of the door. As the rotating

saw blades

66 and 68 penetrate the door edge wall 22 they form parallel slots in the wall. These slots can be lengthened by manually shifting carrier 36 in the arrow 400 directions. Such shifting movements of the carrier are limited by the angle iron stops 33 and 35 carried by guide 10. The stops are located so that the blade edges move to the

straight edges

19 and 21 formed by opening 23 without quite touching these straight edges or cutting into them. Since

blades

66 and 68 are the same diameter and are positioned on the same shaft they form parallel slots of the same or equal length.

The slot length can be increased to a value greater than the spacing between

straight edges

19 and 21 by repositioning and reclamping guide 10 at different locations along the edge of the door. For example, assume that opening 23 is sized so that

straight edges

19 and 21 are spaced apart about 2 if; inches, and it is desired to form a cut-out in the edge of the door 3 inches long; guide 10 would be clamped in a first position, saw carrier 36 would be operated a first time to form slots 2 36 inches long, guide 10 would be reclamped in a new location displaced five-eighths inches, and the saw-carrier would be operated a second time to form the desired length slots.

The door edge material between hole 29 and the saw-formed slots can be severed by chizzling away the space between hole 29 and the slots, preferably at points 15 where the separating material is of minimum width (see FIG. 6). The drilling and chizzling operations serve to subdivide the door material into two separate tabs, one of which is shown at 80 in FIG. 2. Tabs 80 can be separated from the door by bending them around the

straight edges

19 and 21, as shown best in FIG. 9. Prior to the actual bending operations the door material is preferably scored or scribed along the straight edge (19 or 21) by a sharp cutting tool such as a hardened scratch awl. The drilled hole 29 allows a pliers or other similar tool to be used to grip tab 80 and bend it back and forth to accomplish the severing operation. During this operation the guide 10 is continued to be clamped on the door so that the guide wall areas 12 adjacent the straight edges act as immobilizing devices to prevent such deflections or movements of the subjacent wall areas 82 as might tend to form jagged edges at the severing joint. In practice, the severed edge is usually straight and non-jagged. The rectangular cut-out formed in the door by the saw slots and bending operations serves to accommodate a conventional lock set, not shown.

Steel doors commonly are built in two general thicknesses, l 56 inches or 1 inches. The lock cut-out width for l inches doors is usually less than the cutout width for the -I 34 inch doors. For example a common cut-out width for 1 inches doors is 1 1/32 inches, whereas a common cut-out width for 1 34 inch doors is about 1 5/32 inches. The blade spacing shown in FIG. 7 would be suitable for the wider cut-out widths used on 1 )2 inch doors, whereas a narrower blade spacing would be required for the 1 3% inch doors; such narrower spacing can be obtained by repositioning the spacer washers against the outer faces of the blades, as previously outlined.

When the apparatus is used with narrower doors, for example I it; inch doors, it is necessary that the clamping screws 24 be further tightened in the nuts 26 so as to bring the springs 28 snug against the door face. It will be understood that screws 24 should have sufficient length and travel to provide the necessary clamping action on both wide and narrow doors.

The illustrated apparatus uses two saw

blades

66 and 68 on a single drive shaft so that two slots are formed simultaneously in the edge of the door. It is believed possible to utilize an apparatus having only one rotary saw blade The blade would form one slot, after which the carrier 36 would be turned end for end so that the single blade could be used to form a second slot adjacent the other face of the door. The employment of two spaced blades on a common drive shaft is however believed preferable because the slot spacing and parallelism are accurately maintained, the time required to form two slots is lessened, and the lengths of the slots are automatically controlled to the same given value.

We claim:

1. A tool for forming a cut-out in the edge of a door comprising first means for positioning two rotary saw blades in line with the edge of the door so that the blade planes parallel the door face; second means for manually forcing the blades into the door edge to form slots and then shifting the blades along the door edge in the direction of the slots thereby increasing the length of the slots; and third means for maintaining the blades in planes paralleling the face of the door during the forcing and shifting periods.

2. The tool of claim 1 which further comprises a straight edged plate locatable on the edge of the door to span the spaces between the ends of the slots so that door material between the slots can be scored along the straight edge and subsequently moved back and forth about the score line in a material-severing operation.

3. The tool of claim 1 wherein the positioning means comprises a channel-like base having its web wall positionable over the door edge with its flanges paralleling the door face, and a saw carrier having wing-like guide walls adapted to closely overlap the outer surfaces of said flanges; said manual forcing means comprising a handle arranged on the carrier so that the carrier can be forced down onto the base and then shifted therealong in a plane paralleling the door face.

4. The tool of claim 1 wherein the wing-like guide walls are provided with slots for removable reception of saw blade bearings.

5. The tool of claim 3 wherein the web wall of the base is provided with an opening which forms parallel straight edges extending normal to the face of the door when the base is in its installed position; said base being provided with stops for limiting the shifting movement of the saw carrier such that the saw blade can move up to the straight edge without actually striking it, whereby the straight edge can thereafter be used as a scoring and bending apparatus to sever material from the edge of the door.