Doorknob Construction

Mortise locks have experienced problems with the attachment of operating trim including knobs and levers to the locks. In a mortise lock installation, the mortise chassis is slid into an edge pocket in the door and it is secured and operated by a transverse square spindle inserted into the chassis. Operating members slide onto the spindle and are retained there by two flanges commonly called roses which are bolted together through the door. These roses carrying the knobs or levers. The knobs or levers must rotate freely independent of the rose, but they must be prevented from escaping axially from the rose.

In the past, the knobs or levers have been retained by snap rings, truarc rings, pins or set screws, none of which have proven to be entirely reliable, or adjustable for tolerance or wear.

The object of this invention is to provide a secure means for attaching knobs and levers to mortise locks.

A further object of the invention is to provide a simple and reliable means for attaching the knob or lever to the mortise lock rose which further provides for axial adjustment of the clearance between the retaining flange and the operating lever.

Yet a further object is to provide a doorknob construction which is inexpensive to manufacture, easy to assembly and yet provides a more secure installation than presently obtained. These and other objects are obtained in a doorknob construction comprising: a rotating hand operator threaded about its centerline of rotation at one end, a non-circular bore in the operator along the centerline of rotation; an adjustment bushing in threaded engagement with the thread on the hand operator, the adjustment bushing having a shoulder provided at one end opposite the hand operator and a journal bearing surface concentric about the centerline of rotation intermediate the shoulder and the opposite end of the adjustment bushing, a hand operator mounting means disposed about the journal bearing surface, the adjustment bushing being further provided with an indexing non-circular hole at the one end disposed concentrically about the centerline of rotation, and a spindle of non-circular cross section inserted into the non-circular bore of said hand operator and said indexing non-circular hole in the adjusting bushing and cooperating with each to rotate the spindle and prevent rotation of the adjustment bushing relative to the hand operator once the spindle is inserted.

FIG. 1 is an iosmetric exploded assembly view of the doorknob construction according to this invention.

FIG. 1 shows an exploded assembly view of a doorknob assembly wherein the hand operator or lever or handle has a threaded male journal 2 provided at one end. For purposes of the embodiment herein described, the male journal is provided with an external thread 3. The handle is further provided with a square recess 4 which extends into the handle or lever for approximately 3 to 6 or more times the width of the square recess.

An adjustment bushing 5 is provided with a hollow bore 6 at one end. The hollow bore 6 is in turn provided with an internal thread 7 which on assembly cooperates with external thread 3 on the handle. The other end of the adjustment bushing is further provided with a star-shaped hole 9 in the face of its other end. The star-shaped hole is concentric about the centerline of the bushing and extends through the face of the bushing 10 into the hollow bore 6.

A mortise lock rose 20 on assembly is interspaced between the handle and the shoulder 8 of the adjustment bushing. The cylindrical outer surface 11 of the bushing forms a journal about which the rose 20 may rotate. The rose in turn is provided with a journal bearing 21 which may be formed as an integral part of the rose or which may be press-fit into a bore in the rose plate. A mounting plate 25 is shown disposed about the journal bearing 21 and an internal bore 27 of the mounting plate cooperates with the journal bearing to allow rotation of the mounting plate relative to the rose.

A rolled edge 26 of the journal bearing 21 serves to retain the mounting plate 25 in the rose. The mounting plate is shown assembled in a hollow bore or recess 28. The mounting plate 25 is essentially a washer-shaped plate having its internal bore 27 cooperating with the journal bearing 21. One face of the mounting plate bears on the face of the internal recess 28 of the rose 20.

The internal recess 28 extends for approximately 1/2 the thickness of the rose. The thickness of the mounting plate 25 is less than the depth of the recess such that when the rolled edge 26 is completed, the mounting plate will not extend beyond the face of the rose. The mounting plate is provided with two mounting screw bosses 29 which are used to assemble the rose to the mortise lock, as is common practice in the industry.

Interspaced between the shoulder of the adjustment bushing and the face of the journal bearing 21 is a spacer 30 which may be made of a plastic material such as nylon. A second spacer 31 is interspaced between the face of the rose and the handle.

On assembly, the adjustment bushing is inserted through the inner bore of journal bearing 21 and the male journal of the handle is then threaded into the internal thread of the adjustment bushing. The adjustment bushing 5 is tightened until the desired clearance is obtained between the shoulder 8, the journal bearing 21 of the rose 20 and the handle including the spacers 30 and 31. The bushing is adjusted to zero clearance, then backed off until the first set of flats in the star hole align with the flats of the square recess.

The spindle 15 is then inserted through the star hole into the square hole of the handle. Serrations 16 provided on the spindle provide edge upset interference to cooperate with the square recess 4 to retain the spindle in the square recess. In addition, the square recess in the handle, the square spindle and the flats of the star hole cooperate to prevent the adjustment bushing 5 from further rotation after assembly. The shoulder 8 of the adjustment bushing nut securely holds the handle to the mounting rose.

It can be appreciated by one skilled in the art that a secure and novel doorknob construction has been described. It should be obvious to one skilled in the art that the male journal, alternatively, may be internally bored and threaded to accept an adjustment bushing which is externally threaded to accomplish the same invention. In addition, the rose and the mounting plate may be one piece construction. Numerous other variations are possible within the scope of the invention, and I do not wish to be limited in the scope of my invention except as claimed.