US2759747A - Door latch - Google Patents

Description

Aug. 21, 1956 F. J. MccoNNELL DooR LATCH Filed' oct. 21,'1952 I N V EN TOR. /PAW/f /Vc' (ff/NIM BY I I7 7 TOPI/EK United States Patent O DOOR LATCH Frank J.- McConnell, New Britain, Conn., assigner to The American Hardware Corporation, New Britain, Conn., a corporation of Connecticut Application October 21, 1952, Serial No. 315,928 Claims. (Cl. 292-169) This invention relates to a door latch and is embodied 1n a latch unit that is particularly adapted for use with a cylindrical door lock.

An object of this invention is to provide a latch unit having novel dogging means therein for preventing depression of the latch bolt from the exterior of the door, by means of a tool, when the said door is closed and the latch bolt of said unit is in engagement with the strike.

A further object of this invention is to provide such a unit with a latch bolt dogging mechanism that is simple in construction, inexpensive to manufacture and is composed of relatively few parts.

Further objects and advantages of this invention will be more clearly understood from the following description and the accompanying drawings in which:

Fig. 1 is a sectional side view of a cylindrical door lock illustrating the manner in which the latch unit, shown in elevation, is secured thereto.

Fig. 2 is a front elevational view of the latch unit.

Fig. 3 is a rear elevational view thereof.

Fig. 4 is a plan View of the latch unit, partially in central horizontal section, illustrating the dogging mechanism in undogging position.

Fig. 5 is a similar view further illustrating the construction of said mechanism.

Fig. 6 is a side view of the latch unit, partially in central vertical section.

Fig. 7 is a view similar to Fig. 5, but showing the dogging mechanism in dogging position.

Fig. 8 is a sectional end view of the latch unit, taken on line 8-8 of Fig. 6, illustrating the position of the dogging member employed in said clogging mechanism when in undogging position.

Fig. 9 is a similar View illustrating the clogging member when in clogging position.

Fig. 10 is an exploded isometric view of some of the parts of the clogging mechanism illustrating the respective positions which they occupy in the latch unit.

My improved door latch unit includes an elongated casing 5 which is circular in cross-section and is provided, at its outer end, with an annular flange 6 that is secured between a face plate 7 and a clamping plate 7-a which is fastened to the face plate in a manner well-known to those skilled in the art and supports the casing relatively thereto; said plates being provided with holes 8 8 therein which receive screws for fastening the latch unit to the door.

A latch bolt 9 is slidably mounted within the outer end of the casing and is provided with a flat side 10 having spaced stop shoulders 10-1-10-:1 at the inner end thereof which engage the inner surface of the face plate 7 adjacent an opening 1li-b therein, similar to the shape of the bolt, through which a portion of the bolt projects.

Said bolt has a slot 11 extending diametrically across its inner end which receives the outer end of a flat retractor har 12 having an opening 13 therein which extends into the slot 11. The bar 12 is rigidly secured to the bolt 9 by peening the material of the bolt into the ICC opening 13 and over its outer edge as illustrated in Figs. S and 10. The retractor bar 12 extends through the casing 5 and is provided, at its inner end, with retractor lugs 12-a12-a.

The casing 5 carries a supporting plate 14 having ears 15-15 extending perpendicularly from the sides thereof which are received in diametrically opposed slots 16--16 in the wall of the casing and engage the ends of said slots to locate the supporting plate in proper position. Said supporting plate is also provided with ears 15-a-15-a which project perpendicularly from the upper and the lower edges of said plate.

A cup-shaped retainer 17 is telescopically received within the inner end of the casing and abuts the ends of the ears 15*15 and 15-a-15-a on said supporting plate which space the end wall 17-a of the retainer from the rear surface of said plate. The retainer 17 has a cover plate 18 supported against its annular edge and the said supporting plate, retainer and cover plate are held in assembled position by means of prongs 19 which project fliom the end of the casing 5 and are bent over said cover p ate.

The intermediate section of the retractor bar 12 extends through and is slidably supported in an opening 20 in the supporting plate 14- and a similar opening 21 in the end wall of the cup-shaped retainer 17. The narrow inner end portion of the retractor bar projects through an opening 22 in the cover plate 18 that is similar to the openings 20 and 21.

The latch unit further includes a camming bar 23 which extends parallel to the retractor bar 12 through the openings 20, 21 and 22 above mentioned. The narrow inner end portion of the camming bar is provided with a longitudinally extending rib 24 which is slidably received in a notch 25 formed in an ear 26 extending into the opening 22 in the cover plate 18 to provide a guide for the inner end of the camming bar and also retain it adjacent the retractor bar as illustrated in the drawings.

The camming bar contains a slot 27 that extends into the outer portion of the bar which is offset relatively to the inner end to provide cam surfaces 28-28 thereon which lead up to elongated platforms 29-29. The said outer end of the camming bar is supported in spaced relation to the retractor bar by a perpendicular extension having shoulders 15d-30 which engage the side of the retractor bar and a finger Sil-a of reduced width which extends into the opening 13 and is engaged by the outer end of a spring 31 contained in said opening and positioned therein by a finger 32 which projects into the opposite end of the spring. The inner end of the camming bar has retractor lugs 33-33 thereon similar to the lugs on the retractor bar, but the camming bar is shorter than the retractor har and said lugs 33-33 are located forwardly of the lugs 12-a-12-a when the latch is in normal projected position. It will be understood that the spring 31 urges the perpendicular extension on the camming bar into contact with the end of the latch bolt 9, but permits movement of said camming bar relatively to the retractor bar, the nger 3GP-a thereby moving in a direction towards the end of the slot 13 and the linger 32 which constitute an abutment means.

The latch bolt 9, the retractor bar 12 and the camming bar 23 are retained in normal extended position, wherein the stop shoulders 1li-a are in engagement with the inner surface of the face plate 7, by means of a spring 34 which has its outer end contained within an opening 35 in the bolt and its inner end in engagement with the supporting plate 14 and is positioned thereon by a pin 36 which is secured to said plate. l

An auxiliary latch bolt 37 is provided in the latch unit and said auxiliary bolt has a semi-cylindrical outer end portion 3S that projects through and is slidably supported in a semi-circular notch 39 in the face plate 7 with its llat side adjacent the at side of the latch bolt. The auxiliary bolt has a cylindrical shank 40 projecting therefrom into the casing which is of a smaller diameter than the end portion 38 providing a shoulder 4l thereon. The inner end of said shank is slidably supported in an opening 42 in the supporting plate 14 and the auxiliary bolt is urged into normal extended position by a spring 43 which surrounds the shank and has its outer end in engagement with the shoulder 41 and its inner end abutting the supporting plate 14. The auxiliary bolt is positioned relatively to the latch bolt 9 by a shoulder 44, provided at the outer end of the shank, which engages the rear surface of the bolt 9. The said shank 40 has a notch 45 in one side thereof having a cam Surface 45 at its inner end.

A dogging plate 47 is contained in the space between the end wall ll7-a of the retainer and the supporting plate 14 and is supported for lateral movement therein by means of the ears llS-a-lS-a, which project rearwardly from the upper and the lower edges of said supporting plate, as illustrated in Fig. 6. Said dogging plate has an opening 49 therein through which the retractor bar 12 and camming bar 23 extend. A dogging nger 50 projects into the opening 49 from the side thereof and extends through the slot 27 in the camming bar 23. Spaced abutment surfaces 51--51 are provided at the edge of the opening 49 adjacent the dogging linger 59 and said abutment surfaces lie in alignment with the platforms 29-29 on the camming bar. When the latch bolt is in normal extended position, the dogging nger is aligned with an opening 52 extending through the intermediate portion of the retractor bar 12.

The dogging plate has a notch 53 in its side edge which receives the end portion of the shank `46 of the auxiliary bolt and the bottom of said notch provides an abutment surface 53-a which is urged into engagement with the periphery of said shank by a U-shaped spring 54 positioned between the side of a notch 55 in said plate and the adjacent ear project-ing from the supporting plate.

When the latch bolt and the auxiliary latch bolt are in normal extended position, the shank 40 of said auxiliary bolt will be engaged by the abutment surface S3-a on the dogging plate to retain the said plate in the position illustrated in Fig. 5 wherein the dogging linger 50 is removed from the opening 52 in the retractor bar 12.

The latch unit above described is particularly adapted for use with a cylindrical door latch operating mechanism such as that illustrated in Fig. l. Said mechanism generally includes a cylindrical casing 56 having a retractor 57 slidably mounted therein which includes fingers SS-S that extend through a notch in the wall of the cylindrical casing 56. Said retractor is actuated by rotatable rollback means, generally indicated at 59, which are operated by inner and outer rotatable spindles carried by the latch operating unit. Said mechanism is usually provided with suitable dogging means, not shown, which are operable from the inner operating member to dog the outer operating member against operation, and with key operated means in the outer operating member for retracting the retractor when the said outer operating member is dogged.

My improved latch unit is secured to the casing 56 of the latch operating unit by means of rearwardly extending legs 6ft-60 which are bent from the upper and the lower edges of the cover plate 18 and are provided, at their end portions, with suitable means for engaging the edge of the slot in the casing as illustrated in Fig. l. When in position thereon, it will be noted that the retractor fingers 58-53 will engage the retractor lugs 3.3-33 on the camming bar while the lugs 12-1--12-1 on the retractor bar 12 will be disposed therebehind. It will also be understood that the camming bar and retractor bar are allowed to move rearwardly independently of the retractor.

ln describing the operation of the latch unit, let it be assumed that the door is open and the mechanisms of the latch unit and the latch operating unit are in the positions illustrated in Figs. 1 through 5. As the door is moved into closed position, the latch bolt will engage the strike, indicated at 61, and be depressed thereby and the auxiliary bolt 37, the retractor bar 12 and the camming bar 23 will move rearwardly independently of the retractor. The dogging plate 47 will be retained in undogging position by the platforms 29-29 on the camming bar which will have moved into the path of the abutment surfaces 51-51 on the dogging plate before the cam surface 46 on the shank 40 of the auxiliary bolt has reached the abutment surface 53-a in said dogging plate and interference of the dogging finger with the retractor bar will be prevented.

When the door has fully closed, the latch bolt is projected into the opening in the strike by the spring 34, but the auxiliary bolt will be retained in depressed position by engagement with the surface of the strike, `as illustrated in Fig. 7. As the latch bolt moves outwardly into said opening, the spring 31 will cause the camming bar 23 to move therewith and, as the platforms 29-29 move out of engagement with the abutments 51--51 on the dogging plate, the spring 54 will urge the dogging plate laterally into the notch in the shank of the auxiliary bolt to thereby position the dogging nger in the opening 52 in the retractor bar 12 and prevent rearward movement of the latch bolt.

When the inner or the outer operating member of the latch operating unit is rotated, or the key operated means is actuated, the retractor will be retracted and will first move the camming bar independently of the retractor bar against the spring 31 until the fingers on the retractor engage the lugs 12-a--12-a on the retractor bar, after which further movement of the retractor will move the retractor bar and camming bar in unison. However, during independent movement of the camming bar, the cam surfaces 2S-28 thereon are brought into engagement with the abutments 51-51 on the dogging plate and, when the rearward movement of the retractor bar is started, said cam surfaces will urge the dogging plate laterally, against the spring 54, to withdraw the dogging finger 50 from the opening 52 in the retractor bar before the forward edge of said opening engages the finger 50 to thereby prevent any interference between the retractor bar and the dogging finger.

When the door is opened and the latch operating unit is returned to normal position by the spring means contained therein, the springs 34 and 43 will urge the latch bolt and the auxiliary latch bolt into normal extended position wherein the shank of said auxiliary bolt will, through engagement thereof with the abutment surface 53-a in the dogging plate, retain said dogging plate out of dogging position, as illustrated in Figs. 5 and 8.

I claim:

l. In a latch unit, a casing, a latch bolt slidable in said casing and normally projecting from one end thereof, means for connecting the inner end of said latch bolt to a retractor, an auxiliary bolt slidable in said casing from a projected to a retracted position, supporting means fastened to said casing, a dogging member slidable upon said supporting means and movable transversely of said latch bolt from a first position clear of said latch bolt to a dogging position wherein inward movement of the latch bolt by pressure on the outer end thereof is prevented, said auxiliary bolt having cam means thereon engageable with said dogging member when said auxiliary bolt is in projected position to force said dogging member out of dogging position, separate cam means adjacent to and movable with said latch bolt and engaged at its inner end by said retractor, outer stop means on said latch bolt engaged with said separate cam means when said latch bolt is in projected position whereby said separate cam means will be moved inwardly if pressure is applied to the outer end of said latch bolt to cam said dogging means out of dogging position when said auxiliary bolt is in projected position, and inner abutment means on said latch bolt spaced from said outer stop means and permitting limited movement of said separate cam means inwardly relatively to said latch bolt to cam said dogging means out of dogging position if said retractor is operated when said auxiliary bolt is held in retracted position by a strike.

2. In a latch unit, a casing, a latch bolt slidable in said casing and normally projecting from one end thereof, means for connecting the inner end of said latch bolt to a retractor, an auxiliary bolt slidable in said casing from a projected to a retracted position, supporting means fastened to said casing, a dogging member slidable upon said supporting means and movable transversely of said latch bolt from a iirst position clear of said latch bolt to a dogging position wherein inward movement of the latch bolt by pressure on the outer end thereof is prevented, said auxiliary bolt having cam means thereon engageable with said dogging member when said auxiliary bolt is in projected position to force said dogging member out of dogging position, separate cam means adjacent to and movable with said latch bolt and engaged at its inner end by said retractor, said cam means having a cam shoulder and an elongated straight portion engageable with said dogging member, outer stop means on said latch bolt engaged with said separate cam means when said latch bolt is in projected position, whereby said separate cam means will be moved inwardly if pressure is applied to the outer end of said 'latch bolt to cam said dogging means out of dogging position when said auxiliary bolt is in projected position, and inner abutment means on said latch bolt spaced from said outer stop means permitting limited movement of said separate cam means inwardly relatively to said latch bolt to cam said dogging means out of dogging position if said retractor is operated when said auxiliary bolt is held in retracted position by a strike.

3. In a latch unit, a casing, a latch bolt slidable in said casing and normally projecting from one end thereof, means for connecting the inner end of said latch bolt to a retractor, an auxiliary bolt slidable in said casing from a projected to a retracted position, supporting means fastened to said casing, a dogging member slidable upon said supporting means and movable transversely of said latch bolt from a rst position clear of said latch bolt to a dogging position wherein inward movement of the latch bolt by pressure on the outer end thereof is prevented, spring means biasing said dogging means into dogging position, said auxiliary bolt having cam means thereon engageable with said dogging member when said auxiliary bolt is in projected position to force said dogging member out of dogging position, separate cam means adjacent to and movable with said latch bolt and engaged at its inner end by said retractor, outer stop means on said latch bolt engaged with said separate cam means when said latch bolt is in projected position whereby said separate cam means will be moved inwardly if pressure is applied to the outer end of said latch bolt to cam said dogging means out of dogging position when said auxiliary bolt is in projected position, spring means biasing said separate cam means against said stop means, and inner abutment means on said bolt spaced from said outer stop means permitting limited movement of said separate cam means inwardly relatively to said latch bolt to cam said dogging means out of dogging position if said retractor is operated when said auxiliary bolt is held in retracted position by a strike.

4. In a latch unit, a casing, a latch bolt slidable in said casing and normally projecting from one end thereof, means for connecting the inner end of said latch bolt to a retractor, an auxiliary bolt slidable in said casing from a projected to a retracted position, supporting means fastened to said casing, a dogging member slidable upon said supporting means and movably transversely of said latch bolt from a iirst position clear of said latch bolt to a dogging position wherein inward movement of the latch bolt by pressure on the outer end thereof is prevented, spring means biasing said dogging member into dogging position, said auxiliary bolt having cam means thereon engageable with said dogging member when said auxiliary bolt is in projected position to force said dogging member out of dogging position, separate cam means adjacent to and movable with said latch bolt and engaged at its inner end by said retractor, said separate cam means having a cam shoulder engageable with said dogging member, an elongated straight portion extending from said shoulder, and a hooked outer end extending through an elongated aperture formed in said latch bolt, a compression spring positioned within said aperture between said bolt and said hooked end for biasing said separate cam means outwardly relative to said latch bolt, said hooked end normally engaging the bolt, the inner end of said separate cam means when the hooked outer end is against said bolt terminating inwardly of the inner end of said latch bolt.

5. In a latch unit, a casing, a latch bolt slidable in said casing and normally projecting from one end thereof, means for connecting the inner end of said latch bolt to a retractor, an auxiliary bolt slidable in said casing from a projected to a retracted position, a supporting plate extending across said casing, a retaining member extending across said casing adjacent said supporting plate, means spacing said plates apart, a dogging plate slidably mounted between said supporting and retaining plates, spring means urging said dogging plate into dogging position, said supporting plate, retaining plate and dogging plate having normally aligned openings therethrough receiving said latch bolt and said auxiliary bolt, said auxiliary bolt having cam means thereon engageable with said dogging plate when said auxiliary bolt is in projected position to force said dogging plate out of dogging position, separate cam means adjacent to and movable with said latch bolt having its inner end extending through said supporting plate, retaining member and said dogging plate and engaged with said retractor, outer stop means on said latch bolt engaged with said separate cam means when said latch bolt is in projected position whereby said separate cam means will be moved inwardly if pressure is applied to the outer end of said latch bolt to cam said dogging means out of dogging position when said auxiliary bolt is in projected position, and inner abutment means on said latch bolt spaced from said outer stop means and permitting limited movement of said separate cam means inwardly relatively to said latch bolt to cam said dogging means out of dogging position if said retractor is operated when said auxiliary bolt is held in retracted position by a strike.

References Cited in the tile of this patent UNITED STATES PATENTS 1,876,081 Schlage Sept. 6, 1932 2,576,648 Smith Nov. 27, 1951 2,591,647 Welch Apr. 1, 1952 2,636,376 McConnell Apr. 28, 1953 2,644,706 McConnell July 7, 1953

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