US3009347A - Latching mechanism - Google Patents

Description

N V- 21, 1961 H. F. GEORGE 3,009,347

LATCHING MECHANISM Filed April 8, 1959 4 Sheets-Sheet 1 Nov. 2T, 1961 H. F. GEORGE LATCHING MECHANISM 4 Sheets-Sheet 2 Filed April 8. 1959 Nov. 21, 1961 H. F. GEORGE LATCHING- MECHANISM Filed April 8, 1959 4 Sheets-Sheet 3 Nov. 21, 1961 H. F: GEORGE 3,009,347

- LATCHING MECHANISM Filed April 8, 1959 r 4 Sheets-Sheet '4 a; [Hill 7 1; 1 22 915 hie 3,009,347 LATCHING MECHANISM Harry F. George, Park Ridge, III. (919 N. Michigan Ave., Chicago 11, Ill.) Filed Apr. 8, 1959, 'Ser. No. 894,979 3 Claims. (Cl. 70-145) This invention relates to improved latching mechanism for doors and similar structures, and is adapted for use in doors made of metal, wood, and other suitable material.

The present invention is an improvement over those disclosed in my United States Letters Patents No. 2,764,014, granted September 25, 1956; No. 2,803,957, granted August 27, 1957; and No. 2,835,125, granted May 20, 1958.

It is very important in the latching and locking mechanism industry that such mechanism be so made that it can be applied to a door or the like readily, with a good fit between the various parts and the holes in the door, to insure economy in installing, and efficiency in operation. Of the present makes of latches and locks of the tubular type, prior to the present invention, great care is necessary in drilling the two inch hole and have it line up with the one inch .hole for the latch bolt assembly to prevent the parts from sticking and causing trouble. Also in latching mechanism as known prior to my invention herein, many other difficulties are experienced in assembling the mechanism with the door, resulting in loss of time, as well as failure of satisfactory operation during use. The above and other difiiculties I have overcome in the present invention.

Among the objects of my invention are: to provide a new and improved latching mechanism; to provide a latching mechanism that is quick and easy to apply to a door or the like, and when applied will give long and satisfactory operation; to provide a latching mechanism in which the latch bolt and pull back bar are in one complete unit, and which can be mounted onto the door surface with only one one inch hole and two three-eighth inch holes through the door, and an easily formed slot near the edge of the door; to provide a novel telescoping arrangement of the main shaft and associated parts, which simplifies installation by having outer and inner parts held together by mounting screws; to provide a novel arrangement of housings for the pull-back bar, the locking bar, and to enable a partial rotation of the inner knob for release of the lock bar in case of emergency; to provide means for preventing opening a locked door from the outside by a thin flat piece of material; to provide means for locking the door from the outside by a key, and a novel arrangement of parts on the inside of the door for unlocking and unlatching the door from the inside; and such further objects, advantages and capabilities, inherently possessed by my invention, as will later more fully appear.

My invention further resides in the combination, construction and arrangement of parts illustrated in the accompanying drawings, and while I have shown therein preferred embodiments I wish it understood that the same are susceptible of modification and change without departing from the spirit of the invention.

In the drawings:

FIG. 1 is a top plan view of a fragmentary portion of the free end of a door, showing my invention applied thereto.

FIG. 2 is a vertical edge elevation looking toward the bottom side of FIG. 1.

FIG. 3 is a horizontal section on the line 3-3 of FIG. 2, with parts being shown in elevation for the sake of clearness.

FIG. 4 is a horizontal section through the axis of retation of the rotatable par-ts, but showing a modified form of latch bolt and pull-back bar, and the lock bar, rotatable parts and escutcheon studs moved through ninety degrees, as compared with FIG. 3.

FIG. 5 is a side elevation looking toward the left hand side of FIG. 2.

FIG. 6 is a vertical section on the line 66 of FIG. 1, showing the latch bolt and pullback bar free for horizontal movement under spring bias.

FIG. 7 is a vertical section on the broken line 77 of FIG. 1. I

FIG. 8 is a vertical section on the line 8-8 of FIG. 1.

FIG. 9 is a view similar to FIG. 6, but showing the latch bolt and pull-back bar locked against rearward movement.

FIG. 10 is an exploded view showing the parts of the main shaft in separated position just before being assembled together.

FIG. 11 is an edge view of the pull-back bar.

FIG. 12 is a detail side elevation of the pull-back bar.

FIG. 13 is a vertical section on the line 1313 of FIG. 3, and FIG. 14 is a fragmentary vertical section on the line 14-14 of FIG. 4.

While my latching mechanism is, for illustrative purposes, shown herein as applied to a wooden door, it is to be understood that it may be applied to a metal door, as well as in any other connection to which it is adapted for latching and locking a movable part with relation to a stationary part.

In the form shown in the drawings my invention comprehends an outer knob or handle 1, and an inner knob or handle 2, which knobs or handles are respectively secured to the opposite ends of a composite main shaft made up of the cylindrical parts 3 and 4 connected together in telescoping relationship for rotation together as a unit upon rotation of either of the outer or inner handles 1 and 2. The outer part 3 of the main shaft is integral with, or otherwise fixed to, the outer knob 1 for rotation therewith, and the liner part 4 of the main shaft is connected to the inner knob 2 for partial rotation with relation thereto.

The door 5, at a suitable location inwardly of its free edge, is formed with a transverse cylindrical opening 6, preferably of one inch diameter, to rotatably receive the main shaft. The door 5 is also formed with a pair of transverse openings 7 and 8, each preferably of three eighths of an inch diameter, one spaced a suitable distance forwardly of the shaft hole 6, and one spaced a suitable distance to the rear thereof. Mounted on the outer face of the door, concentrically with the shaft hole 6, is an escutcheon 9, having an opening 10 to rotatably receive the outer part 3 of the main shaft. Integrally, or otherwise, fixed to the escutch-eon 9 are a pair of escutcheon studs 13 and 14, which studs extend into holes 7 and 8 respectively of the door.

Mounted against the inner surface of the door is a housing 15, formed with an opening through which the innerpart 4 of the main shaft rotatably extends. At suitable distances from the shaft part 4 are a pair of openings in housing 15, through which extend headed screw members 16 and 17 having threaded engagement with the escutcheon studs 13 and 14 respectively, so that tightening of these screw members with relation to the escuteheon studs will clamp the escutcheon 9 and the housing 15 firmly against the opposite side faces of the door. As seen in FIGS. 1-3 and 5, 6, and 9, the housingI'lS extends to the edge of the door, and as seen in FIGS. 5, 6 and 9, the end of this housing farthest away from the edge of the door is curved on a radius the center of which is on the axis of rotation of the main shaft.

Mounted against the exterior face of the housing 15,

for rotational and radial sliding movements with relation thereto, is a locking control member housing 18 having a peripheral flange in contact with housing 15, the hollow interior of housing 18 being greater in an axial direction than that of housing 15. The flat external wall of housing 18 is formed with a central opening 19, through which rotatably passes the part 4 of the main shaft, opening 19 being elongated to permit radial sliding movement of housing, to effect locking and unlocking of the main shaft as later more fully explained. This elongation of opening 19 is seen at 20 in FIG. 4.

Mounted against the exterior face of the housing 18 is a housing 21 that may be integral with, or otherwise fixed as desired, to the inner knob 2 for rotation therewith, the peripheral flange of housing 21 having rotational sliding contact with the adjacent face of housing 18.

As seen in FIG. 10, the outer part 3 of the main shaft is formed with a circumferential groove 22, within which is seated a ring 23 of suflicient thickness toproject radially and be clamped between the central sleeve 24 of the escutcheon 9 and the outer face of the door 5, to hold the shaft part 3 and the outer knob 1 against axial displacement with relation to the door, as seen in FIGS. 3 and 4. The knob 1 and the shaft part 3, as far as ring 23, is formed with an axially extending bore 25 within the outer end of which is fixed a locking member 26 having a lock cylinder of the tumbler type operated by a key 27. Tumbler lock 26 is of the conventional type in which the key may be removed from the lock cylinder either in the neutral position, or from an advanced position, after the key has been turned. The locking plug of the tumbler lock is fixed to the shaft 28 which has fixed to extend inwardly therefrom the square shaft 29, these parts being rotated with the key 27 as the key rotates in the tumbler look. A ring 30 permits rotation of the shaft 28-29, but prevents the shaft and lock from having longitudinal axial movement in the bore 25.

The bore 25 in outer part 3 of the main shaft is sufiiciently larger than square shaft 29 to permit its rotation therein. Just beyond the circumferential groove 22 the bore 25 is enlarged to a larger diameter bore 31 to receive the adjacent end 32 of the part 4 in telescoping relation, as will be understood in FIGS. 3 and 4. At a portion of its cylindrical wall, bore 31 is formed with a slightly inwardly extending flattened portion 33 which engages over the complemental flattened seat 34 formed on the circumference of the inner end portion of main shaft part 4, whereby when the adjacent end of part 4 is telescoped into bore 31 of part 3, these two parts will rotate together when either the outer or inner knob is rotated, see FIG. 13.

Before assembling together parts 3 and 4 of the main shaft, a short cylindrical locking shaft 35, having an axially extending square opening 36 of a cross-sectional size to fit over the inner free end of square shaft 29, is telescopically inserted into the longitudinally extending cylindrical opening 37 in the main shaft part 4, see FIGS. 3 and 4. As seen in FIG. 10, the locking cylinder 35 is formed on its left hand end, as viewed in FIG. 10, with a narrow, fiat-faced and slightly tapering web 38, shown in cross-section in FIGS. 6 and 9, for a purpose later more fully explained. Fixed adjacent the bottom end of web 38, as viewed in FIG. 10, is a longitudinally extending eccentric pin 39 movable in a circular path as the square shaft 29 and locking shaft 35 are rotated under action of the key 27. When the locking shaft 35 is telescoped home into the adjacent end of part 4, the web 38 will be rotatably positioned in registry with the slot 40 which is formed laterally in cylindrical part 4 and extending halfway therethrough. Also formed in part 4 is a hole 41 extending laterally therethrough to slidably receive the lock bar 42 which has a recess 43 formed in its inner side to receive the eccentric pin 39. Recess 43 is larger than the diameter of eccentric pin 39 to give the necessary play for movement of this pin therein dur- 4 ing the locking and unlocking operations. The part 4 has a suitable opening between the bore 37 and the lock bar hole 41 to accommodate movement of the eccentric pin 39.

Stamped out of, or otherwise fixed to the vertical face of the housing 15, adjacent to the lock bar 42 and one on each side thereof, are a pair of cars 44 and 45, see FIG. 8, between the edges of which ears the lock bar extends when moved to locking position, the lock bar being free or" these cars when moved to unlocking position. Fixed to the interior of housing 18, see FIG. 4, is a block or lug 46 having an opening 47 extending therethrough in a direction radially of the main shaft. Through opening 47 extends a rod 48 having screw threaded engagement at its inner end with the adjacent end of lock bar 42, and having at its outer end a head 49 contacting the outer surface of the circumferential flange of housing 13. Head 49 is provided with one or more slots to be engaged by a screw driver for securing the screw threaded rod 48 to lock bar 42. It is thus seen that the housing 18 may have rotational movement with relation to the fixed housing 15 when the main shaft is rotated, and also radial movement with relation to housing 15 when the lock bar 42 is moved radially in the main shaft by the key 27 and square shaft 29 described above, or by a partial rotation of the inner knob as will be latter explained. Also this radial movement of the housing 18 enables the lock bar to be moved into and out of locking position by moving the housing 18 manually from the inside of the door. This enables the door to be locked from the outside by a key, and to be locked or unlocked from the inside of the door independently of the key.

The housing 21 is fixed to the inner knob 2 to rotate therewith, and has contact with the vertical face of housing 18 to permit the latter to have said rotational and radial movement. As seen in FIG. 4, inner knob 2 is mounted on the inner end of the main shaft part 4, and held thereon for partial rotation with relation thereto. Knob 2 extends radially inwardly over the adjacent end of main shaft part 4, where it is provided with a central opening 50 having a counterbore 51 for the reception of a head 52 of a cap screw 53 threadably engaging complemental threads in an axially extending hole 54 centrally formed in that portion of the main shaft part 4 from its inner end to the transverse lock bar hole 41. A cap 55, having spring fingers, is pushed into the counterbore 51 to cover the head 52 of the cap screw 53.

Before the inner knob is secured to the main shaft part 4 by the cap screw 53, a ball 56 is inserted into the hole 54, which hole decreases in diameter as it approaches the lock bar 42 its diameter at the side of the lock bar being only enough larger than the ball to permit the ball to be movable therein axially of the main shaft. The adjacent face of the lock bar 42 is formed with a pair of spaced transverse grooves 57 and 53, as seen in FIGS. 4 and 8, which grooves may be shorter in length than shown, or merely recesses, if desired. Behind the ball is inserted a coil spring 59 which is held under compression against the ball by a screw plug 69 threaded to the desired position in the screw threaded hole 54. The knob 2 is then applied to the main shaft part 4 by the cap screw 53. It is thus seen that the ball 56 serves as a detent to be yieldably urged into one or the other of the grooves or depressions 57 or 58 when opposite the same, to yieldably hold the lock bar 42 in locked or unlocked position without danger of slipping out of such position until moved intentionally during operation. The ball 56 enters groove or depression 57 when the lock bar is in unlocked position, see FIG. 8, and groove or depression 58 when in locked position.

The vertical wall of housing 18, below the main shaft part 4 as viewed in FIG. 4, has fixed thereto to extend outwardly into the hollow interior of the housing 21, a lug or screw head 61. Housing 21 is formed on its interior with a thickened portion 62 having a central bore 63 for partial rotation on the main shaft part 4-. Thickened portion 62 is formed with a depression 64 the bottom edges of which are beveled upwardly and outwardly in opposite directions from the middle, to form two cam surfaces 65 and 66 against and over which the head 61 of housing 18 rides when the lock bar 42 is in locked position and the inner knob 2 and housing 21 are rotated a limited amount on the main shaft part 4. With lock bar 42 in locked position, and the detent ball 56 in depression 58, the head 61 will be in midposition at the lowest portions of the two cam surfaces 65 and 66. Rotation of the inner knob 2 and housing 21 a restricted amount in either direction with relation to the main shaft part 4, will cause one or the other of the two cam surfaces 65 or 66, depending upon the direction of rotation, to push upwardly against the head 61 and move the locking control housing It; and the lock bar 42 into unlocked position.

To limit or restrict the amount of rotation of the inner knob and housing 21 with relation to the main shaft part 4, the inner end of the latter is formed with a cut-away portion extending laterally inwardly not quite to the axial hole 54 in part 4, and longitudinally a short distance into part 4, to form a recess 67, sidewise in which swings a projection 68 fixed to the inner knob and extending radially into recess 67. To urge said projection 63 to normally stand in midposition in recess 67, main shaft part 4 is formed on the two sides of recess 67 and projection 68 with a pair of laterally and circumferentially extending slots 69-10 to receive compression coil springs 71- 72 respectively, each of which coil springs bears at its rear end against the bottom end of its slot and at its for- Ward end against projection 68. This structure enables the door to be instantly unlocked from the inside, in case of fire or other emergency, merely by grasping the inner knob and turning it in either direction, even though the door had been locked from the outside by a key. It will also be understood that when the inner knob has been rotated in either direction to the limit of its restricted rotation with relation to the main shaft, continued rotation of the inner knob in that direction will cause rotation of the main shaft, for unlatching the door, by reason of the projection 68 contacting one or the other side of the recess 67.

In order to provide a horizontal slot in the inner face of the door to receive the latch bolt 73, two one inch holes are drilled in the door inner face to slightly overlap each other laterally and extend approximately half way through the thickness of the door. By using a knife, or other cutting tool, the top and bottom of the slot can be evened up to form a straight sided slot 74, see FIG. 3. Fixed in slot 74 is a latch bolt housing of sheet metal or the like, and having a back wall 75, top and bottom walls 76 and 77, and an inner end wall 78 spaced a slight distance from the adjacent anchor stud 14, see FIGS. 3, 6 and 9. The latch bolt 73 is slidably mounted in the outer end of the latch bolt housing and is provided with an inner abutment member79 against which seats the outer end of each of a pair of compression coil springs 8i and 31, the inner ends of which coil springs seat against the latch bolt housing inner end wall 78, to normally urge the latch bolt into projected position.

Fixed to the latch bolt to extend laterally therethrough is a pin 82 flush with the exterior face of the latch bolt at one end, and extending a short distance beyond the opposite face of the latch bolt at the other end, see FIG. 3. Fixed by riveting, or otherwise as desired, to the projecting end of the pin 82, is the forward end of the pullback bar 33 which is slidably mounted in the housing 15 between its vertical wall and the inner surface of the door, see FIGS. 3, 6 and 9. Pull-back bar 83 is widened at its rear end or main portion, and of a width approximately that of the adjacent side of the latch bolt housing at its forward end.

The widened rear end of the pull-back bar 33 is formed with an elongated slot 84 of a width at its rear end just enough greater than the diameter of the main shaft part 4 to freely slide thereover, and narrower at its forward end to afford reciprocation of the pull-back bar with relation to the anchor bolt 17. Pull-back bar 83 at its rear end is formed with a slot 85 to allow sufiicient reciprocation of the pullback bar with relation to the anchor bolt 16. A pair of lugs 86S7, one on each side of the widened end of the pull-back bar and carried by either the vertical wall of housing 15 or the inner surface of the door, as desired, afford means to guide the pull-back bar in its reciprocal movement, see FIG. 9.

Referring to FIG. 10, it will be seen that the main shaft part 4 is formed, adjacent the lock bar hole 41, with the laterally extending slot 40, referred to earlier herein, within which the web 38 of the locking shaft 35 swings during rotation of the locking shaft by means of square shaft 29 under action of the key 27. Slot 40 extending half way through main shaft 4 results in the production of the two roll-back noses 88 and 89, one on each side of the bore 37 in part 4, see FIG. 6. At the rear end of the enlarged part of the pull-back bar slot 84 is formed, one on each edge, a pair of shoulders and 91, each of which engages one of the roll-back noses 8S and 89 so that rotation of the main shaft in either direction will cause one or the other of these roll-back noses to push rearwardly on its respective shoulder 90 or 91 to move the pull-back bar and its attached latch bolt inwardly for unlatching purposes. Release of such turning force will cause return of the pull-back bar and the latch bolt to latching position under action of the coil springs 80 and 81.

As seen in FIG. 12 the enlarged part of the pull-back bar slot 84 is extended rearwardly a short distance to form a fan-shaped recess 92 having on its two side edges a pair of inwardly projecting abutment tongues 93-94. The free swinging edge of the web 38 of the locking shaft swings back and forth in the fan-shaped recess 92 under action of the key 27 in the outer knob 1, until it strikes one or the other of the abutment tongues 9394, depending on the direction of rotation. When the key is pulled out of the lock in neutral position, the web 38 will stand in midposition in the fan-shaped recess 92 as seen in FIG. 6. FIG. 9 shows the web in contact with abutment tongue 93, the key having been removed from the lock in advanced position, to prevent the opening of a locked door by inserting a strip of thin fiat material between the edge of the door and the frame.

As seen from the above, I have provided a novel arrangement of latching mechanism, and latch bolt assembly, which can be quickly and easily applied to the door, it only being necessary to form in the door a one inch hole to receive the main shaft, two holes three eighths of an inch in diameter to receive the anchor bolts to clamp the outer par-ts of the main shaft to the inner parts thereof, and an easily formed open slot or recess in the inner face of the door to receive the latch bolt which is fixed as a unitary part to the pull-back bar slidably mounted in the housing 15.

In FIGS. 4 and i4 is shown a modified arrangement for mounting the latch bolt in the door, in which the latch bolt is mounted in the center of the door. In this form a hole 95 is bored, or cut, into the edge of the door centrally thereof, but preferably a little short of the lateral hole 6 in which the main shaft is mounted, as seen in FIG. 4. At the inner end of the hole 95, to extend inwardly from this hole to the inner surface of the door, is a slot 96 of a length and size to permit movement therein of the pin 82, connected between the pull-back bar 83' and the latch bolt 73, during movement of the latch bolt and pull-back bar. The latch bolt 73 is slid ably mounted in a latch bolt housing 75' stationarily fixed in the outer end of the hole 95. Latch bolt 73 ha fixed thereto, by a pin 97 or otherwise as desired, a latch bolt bar 98 having at its rear end a vertically extending slot 99, see FIG. 14, through which the pin 82' of the pullaccess? back bar 83' extends. Coiled around the latch bolt bar 98, between the inner end wall 78' of the latch bolt housing 75 and the latch bolt 73, is a compression spring 100 to normally urge the latch bolt to projected position. As will be understood, inner end wall 78 has an opening to permit the latch bolt bar 98 to have sliding movement therethrough during retraction of the latch bolt. Also, as will be understood, the pull- back bar 83 and 83, will slide in its housing 15 when the latch bolt 73 and 73 is moved in its housing in the door. Both the latch bolt and the pull-back bar will be prevented from movement, when the key 27 is pulled out of the lock in advanced position, by reason of the web 38 of the locking shaft 35 being in contact with one or the other of the abutment tongues 93 or 94 to prevent opening a locked door from the outside by a strip of thin material, as stated earlier herein.

As seen in FIG. 3, when the latch bolt recess 74 is formed to open into the inner face of the door, the two anchor studs 13 and 14 are located in a horizontal plane on opposite sides of the main shaft, with the lock bar 42 moving up and down vertically during its operation. When the latch bolt is located centrally of the thickness of the door as in FIGS. 4 and 14, the hole 95 for receiving the latch bolt 73 is somewhat longer to afford room for movement of the inner end of the latch bolt bar 98, and to afford such extra room the anchor studs 13 and 14 are rotated ninety degrees to be located in a vertical plane on opposite sides of the main shaft, so that they will not interfere with the end of the latch bolt bar 98, as will be understood in FIG. 4. The lock bar 42 may then move in a horizontal path.

In the form shown in FIGS. 1, 3 and 6, the pull-back bar housing 15 will be of semicircular contour on the inner side of the main shaft, and from there it extends with parallel side edges to the free edge of the door where it is bent at right angles to extend across the free edge of the door to be secured by screws or the like as desired, see FIGS. 1, 2, and 6. In the form. shown in FIG. 4 the pull-back bar housing 15 is fully round in contour, because of the shorter length of the pullback bar 83'.

The provision of the vertically extending slot 99 in the inner end portion of the latch bolt bar 98, see FIG. 14, enables an amount of automatic vertical adjustment of the latch bolt with relation to the pin 82 of the pullback bar 83, to take care of improper machining of the door.

Having described my invention, I claim:

1. Door latching mechanism, comprising, a.two-part main shaft having an outer cylindrical part and a separate inner cylindrical part, each of said cylindrical parts having a turning member, the outer cylindrical part having a longitudinally extending axial bore for the greater part of its length which bore at its inner end opens into a concentric enlarged bore which extends to and through the inner end of the outer cylindrical part, said inner cylindrical part having an axial bore open at the inner end thereof, a short locking shaft rotatably mounted in the axial bore of the inner cylindrical part and entirely confined therein, the inner end of the inner cylindrical part being telescopically inserted into the enlarged bore of the outer cylindrical part, means in the telescoping portions of said inner and outer cylindrical parts to fix them for rotation together when telescoped and be separable longitudinally, said locking shaft having a noncircular axial opening extending into its inner end, a key-operated shaft rotatably mounted in said first men tioned longitudinal axial bore of the outer cylindrical part and having a complemental noncircular end to slidably and removably fit into the noncircular opening of the locking shaft for rotating the locking shaft With relation to the main shaft, 21 first housing adapted to be secured against the inner face of a door, a spring-biased latch bolt reciprocally movable at right angles to the main shaft, a pull-back bar connected to the latch bolt and mounted in the first housing for sliding movement between the inner face of the housing and inner face of the door, a second housing in slidable contact with the adjacent face of the first housing, a lock bar in said inner cylindrical part for sliding movement transversely therein, said lock bar being fixed to the second housing for movement therewith, a third housing in slidable contact with the second housing and fixed to rotate with the inner turning member, and means in the third housing for enabling partial rotation of the inner turning member with relation to the main shaft.

2. Door latching mechanism, comprising, a main shaft adapted to be mounted to extend transversely through a door, the main shaft having an outer cylindrical part and a separate inner cylindnical part, the outer cylindrical part having a longitudinally extending axial bore which at its inner end opens into an enlarged bore formed axially in the inner end of the outer cylindrical part, said enlarged bore opening through said last mentioned inner end, said inner cylindrical part having its and adjacent the inner end of the outer cylindrical part telescoped into said enlarged bore, means in said telescoping parts fixing the outer and inner cylindrical parts for rotation together when telescoped and be longitudinally separable one from the other, said inner cylindrical part having a bore open to its inner end, a short locking shaft rotatable in the last mentioned bore, a key-operated shaft rotatably mounted in the first mentioned longitudinal axial bore of the outer cylindrical part, said key-operated shaft being separably connected to the locking shaft for rotation thereof, a spring-biased latch bolt reciprocally movable at right angles to the main shaft, a pull-back bar connected to the latch bolt, a first housing adapted to be secured against the inner face of a door, said pull-back bar being mounted in the first housing for sliding flatwise against the inner face of a door and being operable by rotation of the inner cylindrical part, a second housing positioned against said first housing, a lock bar transversely slidable in the inner cylindrical part, means in the second housing connected to the lock bar, and means connecting the lock bar with the locking shaft, whereby the lock bar may be operated by either the locking shaft or the second housing.

3. Door latching mechanism as claimed in claim 2, the connection between the pull-back bar and the latch bolt having a latch bolt bar fixed to the latch bolt and formed in its rear end with a vertical slot, and a laterally extending pin fixed to the pull-back bar and extending through said vertical slot in the latch 'bolt bar to enable an amount of automatic vertical adjustment between the latch bolt and the pull-back bar to compensate during installation for improper machining of the door.

References Cited in the file of this patent UNITED STATES PATENTS 186,018 Ransom Jan. 9, 1877 431,845 Hope July 8, 1890 858,396 Issleib July 2, 1907 1,060,413 Augenbraun Apr. 29, 1913 1,653,512 Schlage Dec. 20, 1921 1,791,029 Hurd Feb. 3, 1931 2,596,949 Welch et al. May 13, 1952 2,803,957 George Apr. 27, 1957 FOREIGN PATENTS 1,996 Sweden Dec. 21, 1889 371,660 Germany Mar. 21, 1923

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