US 4,394,821 A · Door lock mechanism

Abstract

A doorknob has a neck in rotational bearing engagement on a knob sleeve and has a pair of inner recesses which open inward to engage a driver lug and open axially to be engageable with the lug by axial knob movement. The sleeve has a cross slot adapted to contain a torque-releasable driver, biased outward to engage its lug in a recess, but with the lug so shaped that it will be cammed out of the recess under excess torque on the knob and hence release the knob and prevent transmission of the excess torque to the knob sleeve. Alternatively, the sleeve cross slot may contain a positive driver such as one having end lugs engaged in both recesses, or may contain no driver so that the knob is freely rotatable on the sleeve. The knob has a large end bore closed by a face closure member retained in place by a buried snap ring. The closure member has an inner cylindrical flange embraced by forward portions of the knob sleeve, and contains a key lock mechanism, preferably a key-removable lock core, which is non-rotatable in the closure member and oriented by engagement in a slot in the sleeve. The knob and face closure member form a self-contained assembly in which the closure member can rotate to receive the core in different orientations to suit doors of different hand, and which permits the knob to rotate as needed, without rotation of the spindle and core and closure member, to protect the lock from excess torque or to suit different functions of the lock.

Claims36

Dependent claims

Door-lock mechanism having a torque-releasable knob, comprising

a knob sleeve mounted for rotation on its axis and connected to retract a door bolt, means for locking the sleeve against rotation to prevent it from retracting the bolt,
a knob mounted for rotation on the axis of the sleeve and having a coaxial part surrounding a part of the sleeve,
means for normally connecting the knob to rotate the sleeve to retract the bolt, and releasable under excessive relative turning force,
said means comprising a drive lug mounted on one of said parts and movable toward the other, drive faces on one and cam faces on the other of said lug and other part, means biasing the lug in a direction to engage said drive and cam faces for transmitting limited torque from the knob to the knob sleeve for rotating the latter to retract the bolt,
said drive and cam faces being so shaped and said biasing means having such force that excessive knob-turning force will cause the lug to be yieldingly cammed to a retracted position to release the normal drive connection from the knob to the sleeve.

2 more elements

Door-lock mechanism, comprising

a knob sleeve having a generally cylindrical knob-receiving portion containing a transverse slot for receiving and supporting a knob driver having a drive lug which projects radially from said knob-receiving portion,
a knob having a handhold portion and a neck portion, said neck portion having an inner cylindrical bearing surface for supporting the knob for possible rotation on the axis of the sleeve and containing an inner lug-receiving recess open inward and axially toward the inner end of the sleeve so as to be axially engageable and disengageable with the lug of a knob driver mounted in said sleeve,
and means to secure the knob axially in place on the sleeve with the recess in position to engage a driver lug,
said mechanism being adapted to have the knob mounted on the sleeve either (a) without a knob driver in said slot so as to be freely rotatable on the sleeve, or (b) with a non-retractable driver lug in said slot so as to provide a positive drive from the knob to the sleeve, or (c) with a yieldingly retractable driver in such slot and having a lug thereon shaped to be yieldingly cammed out of engagement with said lug-receiving recess by excessive knob-turning force so as to provide a torque-releasable drive between the knob and sleeve.

1 more element

Door-lock mechanism, comprising

a generally cylindrical knob sleeve including a forward portion,
a knob having a large circular opening in its outer end and having a neck portion surrounding said sleeve and coaxial therewith,
a circular face closure member received in said knob end opening, said knob opening and face closure member having facing peripheral grooves at the circular interface therebetween, and a retaining ring contained in and bridging said grooves to secure the face closure member in said opening and rotatable therein relative to the knob,
said closure member having a rearward extending flange engaged in the forward portion of the knob sleeve for supporting the outer end of the knob.

1 more element

Dependencies are inferred from the claim text.

Door lock mechanism

Life of this patent

Door lock mechanism

Life of this patent

Abstract

Claims36