IMPROVEMENTS IN THE MANUFACTURE OF METALLIC DOOR AND OTHER KNOBS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Alfred Heath and Rowland Francis
Heath at the Office of the Commissioners of Patents on the 10th November
1880.
ALFRED HEATH and ROWLAND FRANCIS HEATH, both of Birmingham, in the
County of Warwick, Manufacturers. "IMPROVEMENTS IN THE MANUFACTURE OF
METALLIC DOOR AND OTHER KNOBS."
Our Invention relates principally to metallic knobs for doors, but is also applicable
to knobs for other purposes, such for example as the knobs used as terminal
ornaments in metallic bedsteads and other articles of metallic furniture.
We will describe our Invention in connection with a door knob.
In making a knob according to our Invention, we form by dies and pressure two
shells of thin sheet brass or other ductile metal or alloy, one of the said shells
having nearly the figure of the neck of the knob, and somewhat more than one
half of the body of the knob to be made. The other shell has nearly the figure of
the remaining portion of the knob to be made, and constitutes the front of the
knob. The widest end of the first described or principal shell is of somewhat
greater diameter than the front shell. In securing the two parts or shells together,
the front shell is inserted in the open wide end of the principal shell, and by
burnishing or spinning, the edge of the principal shell is turned over the edge of
the front shell. The two shells are thus securely joined together. As the part of
the knob of largest diameter is grasped by the hand in turning the knob, and as
the said part of largest diameter is part of the principal shell, that is, the part
which is secured to the spindle of the knob, the action of the knob is not interfered
with should the front shell become loose or capable of turning in the other shell, the
front shell not being gripped by the hand in turning the knob.
Or the shell forming the front of the knob may be of larger diameter than the
other shell, and the two shells may be connected by the edge of the front shell
being burnished or spun over the edge of the other shell. In this case the tendency
of the front shell to turn on the other shell is counteracted by an internal soldering
together of the two shells effected by means of a blow pipe or otherwise.
The iron or other bush having in it the square hole into which the spindle of the
knob is inserted, is fixed in the neck of the knob, either by inserting it in the open
end of the neck, and closing the extreme end of the neck upon it by pressure, either

page_text: before or after the two shells are connected, or before the two shells are connected,
the end of the neck is first turned inwards, and the bush introduced into its place
from the open wide end of the principal shell. By giving rotary motion in a lathe
to the principal shell having the bush in its neck, and applying a pressing tool to
that part of the neck where the bush is situated, the neck is pressed at that part
into a groove in the bush, and the bush thereby fixed in its place.
The front shell is afterwards fixed in the principal shell by burnishing or
spinning.
The application of our Invention to knobs other than door knobs differs in no
essential respect from its application to door knobs, as herein described.