IMPROVEMENTS IN THE MEANS EMPLOYED FOR SECURING DOOR KNOBS TO THEIR SPINDLES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by John Thom at the Office of the
Commissioners of Patents on the 21st March 1882.
JOHN THOM, of Wolverhampton in the County of Stafford,
"IMPROVEMENTS
IN THE MEANS EMPLOYED FOR SECURING DOOR KNOBS TO THEIR SPINDLES
"
The object of this invention is to produce a cheap and simple method of securing
door knobs to their spindles by which the common and troublesome set screw may
be dispensed with and a more accurate adjustment of the position of the knob upon
the spindle obtained, besides ensuring that the knob will not work loose in ordinary
use, and yet be capable of being readily removed when desired.
I am aware that there are several inventions for securing door knobs to their
spindles, which dispense with the need for the common set-screw, but I claim that
my invention combines simplicity and efficiency in a manner not attained by
previous inventions having the same object.
I use preferably a square spindle with a screw-thread run upon the angles
thereof. A collar or nut runs first upon the screwed spindle and the said collar or
nut has a screwed concentric plug projecting from it on the side towards the knob.
The knob has a hole down its axis which is square for a part of its length to fit
the spindle as in the ordinary manner, but the hole is circular and of an enlarged
diameter for a short distance from the inner face of the knob and the circular part
is screwed to receive the screwed plug on the collar or nut aforesaid. The screw
on the spindle is right-handed and that on the plug left-handed (or vice-versa).
The knob is secured on the spindle in the following manner; the collar or nut is
screwed up along the spindle to within, or nearly within, the same distance of the
rose or lock case as the thickness of the plug, and the knob is then pushed up
against the plug and the collar or nut screwed up along the spindle towards the
rose or lock case by which means the plug on the collar or uut is screwed into the
screwed part of the hole in the axis of the knob as the collar or nut is screwed
along the spindle, and the knob is thus brought up against the outer face of the
collar or nut as the inner face of the collar or nut is brought up, or as nearly so as
may be desired, against the rose or lock case.
The screw threads on the spindle and on the plug respectively are preferably of
the same pitch; if otherwise the distance of the collar or nut from the rose or lock

page_text: case as the knob is about to be fixed must vary according to the difference in the
pitches of the respective screws. The edge of the collar or nut is preferably milled
to give a better hold for the fingers in screwing it. A moderate pressure or force
exerted around the edge of the collar or nut is sufficient to tighten the knob firmly
to the collar or nut and consequently to the spindle.
Instead of a screwed plug upon the collar or nut and a correspondingly screwed
hole in the knob, the collar or nut may be formed with a female screw to screw
over a male screw at the inner end of the knob
As the knob has a square hole down part of its axis and is mounted on a square
spindle the strain in turning the spindle passes direct from the knob thereto, the collar
or nut simply turning slightly on the screwed part of the spindle if there is any
looseness of the knob upon the spindle, and there is therefor no tendency for the
collar or nut and knob to become disconnected. The collar or nut cannot of course
unscrew along the spindle so long as the knob is tightly held to the face of the
collar or nut.
The spindle is not necessarily round, as any shape in section will answer the
purpose of this invention if such shape will admit of a screw-thread being run upon
the spindle and will also prevent the knob from turning thereon when a part of
the hole down the axis of the knob is of the same shape and size in cross section as
the spindle.
As a rule one of a pair of knobs only is fixed in the manner herein-before
described, the other knob being fixed permanently in any manner now employed
for that purpose.