US2185863A - Knob and spindle mechanism for door latches - Google Patents

Description

Jan. 2, 1940. J. MILLER vKNOB AND SPINDLE MEGHANISM FOR DOOR LATGHES Filed July 7, 1938:

INVENTOR Uu ATTORNEY Patented Jan. 2, 1940 KNOB AND SPINDLE MECHANISM LATCHES Julius Miller,

Fon Doon Application July 7, 1938, SerialNo. 217,862

1 Claim.

This invention relates to knob and spindle mechanism for door latches of the type in which a spring-projected latch bolt automatically engages a latch plate on a door jamb adjacent thev l `rendered valternately operative and inoperative by manipulation of the spindle, such manipulation being normally possible the door. y

Aiurther object of the invention is to provide a door knob and plate combined as a unit whereby the knob cannot be removed from the spindle without removing the plate from the door, in combination with means for'securing the plate to the-door, which means is invisible at the outside of the door when the plate is in position thereon.

Other objects and advantages of the invention will appear as the description proceeds.

In the accompanying drawing,

Fig. 1 is a longitudinal sectional view of a knob and spindle mechanism constructed in accordance with the present invention, attached to a portion of a door, both knobs being shown in operative engagement with the spindle;

Fig. 2 is a View similar to Fig. 1, but showing the spindle out of operative engagement with one of the knobs; i

Fig. 3 is an end view of the knob shown at the left in Fig. 2, said knob being detached from its door plate; and

Fig. 4 is a perspective view of the spindle assembly with the permanentlyv operative knob attached thereto. l

Referring to the drawing, I designates a portion of a door which may be assumed to be hinged at one edge to the door frame and at its opposite edge provided with an automatically acting spring latch, the latch bolt of which (not shown) is actuated by a cam follower 2, through which passes a spindle 3 oi generally square shape in cross-section, whereby rotary motion of the spindle will serve to rotate the cam 2 thereby to only at one side of retract the latch against the tension of its spring. f

At oneend of the spindle a knob 4 is secured thereto in the usual manner, name1y,the corners (Cl. l0-149) of the square-spindle 'are threaded for engagement with an interiorly vthreadedbore in the shank of the knob t therebyto permit adjustment of the operative length of the spindle l:for

use with doors of different'thicknesses, the usual set screw 5 passing radially through the shank of the knob into engagement with one of the at sides of the spindle for maintaining the knob in its adjusted position on the spindle. The shank of the knob Il is provided at the end thereof adjacent the door with a cylindrical portion 4@ of smaller diameter than the rest oi the shank,

said portion being adapted to pass freely through a central opening-ina door plate 6. .The said portion la has formed therein an annular groove in which is mounted a split ring l' preferably made of spring wire of round cross section.

' At the opposite or outer side of thedoor, a

plate 8 is provided in which is mounted for free rotation'the shank of a knob 9, the end of the Aknob shank beingv flanged over at the inner side of the plate to prevent separation of the knob and plate, so that these two members constitute a unit.l The plate Bis 'preferably provided at its inner side with a plurality of interiorly threaded Uli sleeves l0 seated in bores extending through the wood o the door,y each of said sleeves being engaged by a screw Il extending through the plate 6 at vthe other side of the door. .This arrangement makes it .impossible-to yremove the knobcarrying plate 8, or tolocate the screws holding said plate,"ex cept from the inside. The knob 9 is provided with an opening l2 therethrough, said opening being squaref'or the ygreater portion ofv its length, while the spindle 3v is provided at the end thereof with a cylindrical portion 3a, immediately adjacent to the square portion.

Secured on the spindle, and dispose'd'within an opening iormed'in the door, is a stop washer I4, which may either be threaded on to the spindle or merely provided.- with a square opening for the passage of the spindle therethrough, and in either case a set screw l5 passes radially through the washer and impinges on the spindle, thereby maintaining the washer at a fixed posif tion. As will be -noted in Figs. l, 2 and 4, the

washer is secured on the spindle at such a p oint portion 3b into and out of engagement with the l square opening I2 of the knob 9.

From the foregoing it will be obvious that the knob 4 is at all times secured to the spindle so that the latter will turn with-the knob and thus impart rotary motion to the cam follower 2 thereby to retract the latch bolt whenever the knob ll is turned. With the spindle in the position shown in Fig. 1, the knob 9 is also operative to turn the spindle because the square portion 3b of the latter is within the square opening I2 oi the knob. However, assuming that the knob 9 is at the outer side of the door and it is desired to prevent operation of the latch bolt from that side, this is accomplished by exerting a slight pull on the inside knob 4 to withdraw the square portion 3b from its square seat in the knob 9, as shown in Fig. 2, in which position the knob 9 may be freely rotated around the cylindrical portion 3a of the spindle but is entirely ineilective to rotate the spindle. The longitudinal move- `ments of the spindle in opposite directions are limited by the abutment or" the washer i4 against the cam follower 2 on one side and against the shank knob 9 and its plate 3 on the other side. The split ring 'I in its expanded condition is of ySlightly larger diameter than the opening in the plate 6 so that when the spindle is in engagement with knob 9 the ring abutsl against the inner side of plate 5 and offers sufficient resistance to the movement of the spindle to prevent accidental disengagement from said knob Sl. On the other hand, owing to the cylindrical form of the stock from which the ring is made. a pull on the knob l causes the ring to contract sufficiently to enter the plate opening as. shown in Fig. 2, the movement of the spindle being stopped by abutment el the washer Ill against the latch follower 2 before the ring passes completely out of the plate opening.

It will thus be readily seen that, with the parts in the position shown in Fig. l, the latch bolt may be operated by turning either knob, but in the position shown in Fig. 2, only the knob 4 is effective to rotate the spindle and thereby withdraw the latch bolt, and that the spindle can be replaced in operative engagement with knob 9 only by pushing on the knob l and, if necessary, turing the latter slightly to carry the square end of the spindle into register with the opening I2 in the shank of knob 9. However, means is provided whereby a person who has accidentally locked himself out by closing the door after him with the parts in the position shown in Fig. 2, may operate the spindle to withdraw the latch bolt. In the example shown in the drawing, the knob 9 is provided with a bore I5 in axial alinement with the square opening I2 and with .the cylindrical portion 3'au of the spindle which is provided at its end with an interiorly threaded bore or socket I6 for engagement with the threaded end of a key Il', whereby one iinding himself locked out may thread the key into the socket and pull the spindle into operative engagement with knob 9, or by rotating the key until it will go no further without turning the spindle and thus withdrawing the latch bolt. While a screw engagement between the spindle and key is shown herein, it will be readily seen that some other form of connection, such for instance as a slot and pin, may be devised to make it dicult for unauthorized persons to operate the spindle from outside the door without having the implement designed for that purpose.

Having thus described my invention, what I claim is: v

In a door latch having an automatically projected latch bolt and rockable means for retracting the same, an actuating spindle in slidable engagement with said retracting means and op erative to a-ctuate the same in all positions of the spindle, a knob secured to the spindle at one end thereof for manually rocking and sliding the spindle, a washer secured to said spindle for limiting the sliding movement of the spindle in opposite directions, a second knob mounted for free rotation in alignment with the opposite end of the spindle and provided with an opening for the reception of a portion of the spindle, said opening and spindle portion being of cooperating form in cross-section whereby when the spindle is slid in one direction it will be operatively engaged by said knob and when slid in the opposite direction the knob willbe free to rotate Without eect on the spindle, a door plate having an opening in which a shank portion of said rst knob is mounted for rotation and sliding movement, said shank portion having a circumferential groove therein, and a split ring of resilient material mounted in said groove and presenting flexible resistance to sliding movement of the shank portion of the knob in said door plate. v

JULIUS MILLER.

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