Improvements in Door Chains.
Year: 1893

page_text: Date of Application, 20th Jan., 1893
Complete Specification Left, 18th Oct., 1893-Accepted, 18th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in Door Chains.
I PERCY GEORGE ALLDAY trading as P. G. Allday & Co. of Northwood
Street in the City of Birmingham Cabinet and General Brassfounder do hereby
declare the nature of this invention to be as follows:-
This invention has for its object the construction of an adjustable door chain and
consists in a chain bolt in two or more parts consisting of a frame with a straight
slot rounded at one end inside of which on both sides is a strip of metal tapering
from one end to the other.
A knob is fitted on a screw piece to which a chain is attached and on the bottom
of the screw piece is a loose nut with pummel attached thereto, to prevent the nut from
turning round when placed in the slot. The knob when placed in the frame will be
secure in any position along the slot according as the screw is lengthened or
shortened by the turning of the said knob. When adjusted to the required position
the knob will bind against the inclined flange or strips of metal at the back of the
slot.
This invention allows a door to be set open and secured to any distance required
up to the full length of chain and the greater the pressure on the door from the
outside the tighter shall the knob bind against the edges of the slot.
I do not wish to confine myself to the precise form described for the knob or
screw head, the nut, or the opening at the end of the slot, as these may be varied
without altering the object of this my invention.
Dated the 19th day of January 1893.
PERCY GEORGE ALLDAY.
COMPLETE SPECIFICATION.
Improvements in Door Chains.
I, PERCY GEORGE ALLDAY, trading as P. G. Allday & Co. of Northwood
Street in the City of Birmingham, Cabinet and General Brassfounders, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying drawings:
This invention relates to a new and improved form of adjustable door chain and
consists in a chain bolt formed of the following parts, namely:-A frame with a
longitudinal opening or slot in its front plate with an enlarged opening at
the one end to allow of the insertion of a bolt on the end of a chain. At
the back or inner edges of this slot the metal is raised so as to form an incline
on both edges from one end to the other. A knob is fitted on a screw-piece
to which a chain is attached and on the bottom of the screw piece is a loose nut with
a pummel upon it to prevent the nut turning round when placed in the slot in the
frame.
When that end of the screw knob which carries the nut is inserted into the
opening at the end of the slot the screw knob may be secured at any point along
the slot according as the screw is lengthened or shortened by turning the knob.
When adjusted to the required position the knob will bind against the inclined
flanges on the edges of the slot.
Referring to the drawings, .

page_text: Fig. 2 is a longitudinal section of the slotted frame, Fig. 3 a transverse section
of the same on line to and Fig. 4 a side view of the screw knoh or bolt.
Similar letters on the various figures relate to similar parts. (a) is the front of
the frame in which is the longitudinal slot (6) with the enlarged opening (c) to
allow of the insertion of the bolt (d) which is attached to the door jamb by the
chain (e) in the usual way. (f) shews the inclined sides of the slot (b).
(d) Fig. 4 is the knob of the bolt fitted on the screw piece (g) upon which is the
loose nut (h) with the pummel (i).
To fasten the bolt the nut portion (/) is passed through the opening (c) and the
knob (d) having been more or less screwed down, the bolt with the punimel (i) lying
in the slot is slid along until it reaches a point where the nut (h) will become
wedged against the inclined flanges (/) of the slot as shewn in enlarged sectional
view Fig. 5. The point at which the wedging takes place being determined by the
distance that has been set between the knob (d) and the nut (h) thus regulating the
extent to which the door may be opened when the chain is fastened and the greater
the pressure put upon the door from the outside the tighter will the knob or bolt
bind against the edges of the slot.
The knob head may be of any desired design and the enlarged opening at the
end of the slot of any desired outline the nut in each case being made of a suitable
shape for inserting therein.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
A door chain which is made adjustable by means of an inclined surface within or
upon the slot through which the bolt at the end of the chain passes, together with
a bolt to slide within the slot, made adjustable substantially as herein set forth and
illustrated.
יזי
HENRY F. TALBOT,
7, Cherry Street, Birmingham, Agent for the Applicant.