Improvements in the Construction of Mica Lamp Chimneys and the like.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Construction of Mica Lamp Chimneys
and the like.
I, THOMAS REDMAN of Rose Mount, Bradford, in the County of Yorkshire,
Gas Engineer, do hereby declare the nature of this invention to be as follows:-
Instead of building the mica chimney up in the usual way, which is fixed
together by a means of rivets and metallic binders, and now in common use,
1 construct the frame by a novel arrangement of parts forming same, in such a
manner that the said sections or combination of sections as regards the transparent
material, may be readily fitted therein or equally readily removed for cleaning,
renewal, or other purposes, and which is accomplished as follows.
At the bottom of the frame I form a suitable ring of metal to which is attached
two or more ribs standing upright, and at the upper ends of which is attached
another suitable ring of metal, the ribs are provided with suitable groves in
which the sections of mica or glass are recived and held in position.
Dated this 2nd day of August 1895.
THOMAS REDMAN.
Improvements in the Construction of Mica Lamp Chimneys
and the like.
1, THOMAS REDMAN, of Rose Mount, Bradford in the County of York, Gas
Engineer 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 :-
The object of my invention is to construct the frame for supporting the mica or
other suitable material forming the transparent portion of a lamp chimney, by a
novel combination of parts so arranged that, the rivets and binders as hitherto
formed are dispensed with, and in lieu thereof to so arrange the frame, that any
section of the transparent material may be readily placed in the lamp chimney or
removed therefrom for cleaning or other purposes; and to so form the framework
that, it is more durable, not so liable to become distorted by the heat from the gas
or other flame, and less costly to manufacture than is the case with chimney frames
of the ordinary construction.
In describing my invention in detail, reference is made to the accompanying
drawings forming part of this specification, in which
Fig. 1 represents an elevation of a lamp chimney formed according to my
invention, a portion of the bottom part is cut away to show the interior.
Fig. 2 is a section through line a. b. with the mica or other transparent material
removed, and
Fig. 3 is a section through line c. d. showing the mica or other transparent
material in position.
In carrying out my invention, I form a metallic ring A for the base or bottom
portion of the lamp chimney frame, which may be flanged at B to give rigidity to
[Price 8d.]

page_text: the base, also an internal flange C may be formed by compressing the material
into the interior, or separate pieces may be inserted for the purpose as
hereinafter described.
The top of the lamp chimney frame is formed by a ring D. preferably provided
with an external flange E. the top and bottom rings D. and A. being attached
together by two or more ribs F. provided with internal flanges, thereby when fixed
in position forming a groove between the flanges F¹ of the ribs F for the reception
of the mica or the like G. which when placed in the said grooves between the said
flanges F¹, rests upon the base flange C or other suitable support formed or placed
in the base ring A.
The flanges F¹ materially strengthen the respective ribs F. so that they are not
so easily bent by the heat from the gas or other flame, or by other causes, and the
said ribs may be attached to the rings by passing the bottom ends through holes
formed in the ting A. and bending the ends over as shown at H in Fig. 1. the top
ends of the said ribs are secured by passing portions of the same through holes in
ring D and bending the ends over the external flange of the top ring D.
The ribs F may also be attached or sufficiently secured to the ring A. for the
purpose, by inserting the ribs F in the ring A. and compressing between each pair
of ribs, a curved and loose piece J shown in detail plan view Fig. 4 and section
Fig. 5 through line e. f. the pieces J being of suitable length are bent to a curve
of greater radius so that, when compressed between the flanges F¹ of ribs F. within
the base ring A. they hold the ribs F in position.
The top ring D may be attached to the ribs F. by forming projections or lugs K
on the ring somewhat as shown by detail Fig. 6. and bending them around the ribs
as shown by Fig. 7. in any case, a groove is formed in the interior of the lamp
chimney between the internal flanges F¹ of the ribs F. so that the sheets of mica or
the like can be inserted or withdrawn from the frame for cleaning, renewal or other
purposes, by sliding them within the lamp chimney and between the flanges F¹ or
the like, without any alteration to the lamp chimney frame.
It will be obvious that the sheets of mica may be secured within the lamp
chimney frame by dispensing with the flanges F¹ on the ribs F. and substituting
therefor, similar but shorter flanges within the top and bottom rings D. and A.
but in that case, the mica or the like will only be secured top and bottom, instead
of the entire length, and in addition the strength of the frame is reduced.
Having now particularly described and ascertained the nature of this my inven
tion, and in what manner the same is to be performed, I declare that what I
claim is.
The construction of a lamp chimney frame by the rings A. and D connected
together by ribs F the whole being so arranged that the transparent material may
be inserted or removed from the frame without any alteration thereto substantially
in the manner as hereinbefore described and illustrated.
Dated this 2nd day of May 1896
THOS. REDMAN.