IMPROVEMENTS IN RACKS FOR TRANSMITTING MOTIVE POWER
Year: 1884

page_text: I BENJAMIN DODD of Bearpark in the County of Durham Colliery Official
do hereby declare the nature of said Invention for "IMPROVEMENTS IN RACKS
FOR TRANSMITTING MOTIVE POWER" to be as follows:-
My Invention has for its object to provide racks (such as are used in connection
with furnaces ovens and retorts or for other purposes) so that they will require less
room for their movement than do the racks as at present constructed.
According to my Invention I make the rack in longitudinal parts capable of
sliding one within or beside the other so that the one part is first moved out by
the operating pinion and then interlocked with the other or second part so that the
parts form virtually one long rack. In withdrawing the rack the operating pinion
first draws in the second and first parts until the second part is out of gear with
the pinion when the unlocking of the parts is effected and the pinion draws the
first part into or beside the second part thus necessitating much less room at the
rear of the arrangement than is necessary with racks as at present used.
The locking device may consist of a wedge and stop piece on the one part of the
rack coming against a correspondingly shaped portion on the other part of the rack
when a catch piece engages behind the wedge piece-The releasing may be effected
by a projection on the rack carrier against which a lever strikes to turn the catch
and release it.
The motion of the rack may be eased by antifriction rollers.

page_text: I BENJAMIN DODD of Bearpark in the County of Durham Mining Engineer do
hereby declare the nature of my invention for "IMPROVEMENTS IN RACKS FOR
TRANSMITTING MOTIVE POWER" and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
My Invention has for its object to provide racks (such as are used in connection
with furnaces ovens and retorts or for other purposes) so that they will require less
room for their movement than do the racks as at present constructed.
According to my Invention I make the rack in longitudinal parts capable of
sliding one within or beside the other, so that the one part is first moved forward
or extended from the other part by the operating pinion, and then interlocked with
the other or second part, which is then in its turn moved forward by the pinion,
the parts forming virtually one long rack when so locked together and operated. In
withdrawing the rack the operating pinion first withdraws the parts together (one
part bringing 'the other with it) until one of the parts is out of gear with the
pinion, when (the unlocking of the parts having been effected just before the
pinion ceases to engage with; the part first withdrawn), the pinion draws, the other
part into or beside the part which is out of gear with the pinion, thus necessitating
much less room at the rear of the arrangement than is necessary with racks as at
present used.
"
The locking device may consist of a stop piece on the one part of the rack
coming against a correspondingly shaped portion on the other part of the rack
when a catch piece engages behind the stop piece. The releasing may be effected
by a projection on the rack carrier, against which a lever strikes to turn the catch
and release it.
The notion of the rack may be eased by antifriction rollers.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of Drawings the same letters of reference
indicating corresponding parts in all the figures. The arrangement illustrated is
one in which the rack is in two longitudinal parts only; as that is the arrangement
by which the action can be best described, racks with more than two longitudinal
parts being merely provided with duplications of the arrangements, now to be
described.
Figure 1 represents a portion of a rack constructed according to my Invention
in the position when the two lengths of rack A and B are interlocked the part A
having been moved by the pinion D and extended from the other part B. Figure 2
is a similar view,but with the parts A and B in the position they assume when
they are unlocked and the pinion has withdrawn the part B of the rack and
is about to withdraw the part 'A' to within the part B. Figures 3 and 4 are insido
views of the interlocking ends of the parts A and B respectively. Figure 5 is a 4
transverse section on the line 1-2 Figure 1.
The rack is made in two longitudinal parts A and B, the part A being capable
of sliding on, against, or between the sides of the part B, its movement being
facilitated by antifriction rollers a, upon which it runs. The part B is with the
same object mounted upon antifriction rollers b, carried by the bed plate C of the 4
apparatus. This bed plate carries bearings c for a pinion D, wide enough to

page_text: engage with the teeth of both parts of the rack. Upon an axis e is fixed a
wedging piece E, situated between the sides of the part B, of the rack in such
a position that it can be either turned up so as to form a lock or stop for the part A
(as in Figure 1) or be turned down clear of the said part A (as in Figure 2.) The
movements of the piece E, for these purposes are effected by a double armed
lever F, F, one or the other of which arms comes into contact with a pin or stud
piece (carried by a projection from the bed plate C) in accordance with the
direction in which the rack is being traversed. The said lever F, F, and pin or
stud piece may be in duplicate one on each side of the rack if desired.
The action of the apparatus is as follows. In protruding the rack or moving it
forward the pinion at starting is engaged only with the part A which is free
to slide in the part B. The pinion therefore moves out the part A until its end
projections bear upon corresponding projections g on the end of the part B and
the piece E is raised into the position, Figure 1 so as to lock the parts together the
said movement of the part E to turn it up into the said position being effected by
the arm which was raised coming into contact with the stud e² and being
depressed by it. The pinion therefore after it is out of gear with the part A.
continues to move it outwards through the intervention of the part B with which
the pinion now gears, the parts A and B now forming virtually one long rack. On
the return motion the pinion by engaging with the part B draws back this part
and with it the part A until it gears also with the said part A. Just before the
pinion ceases to gear with the part B of the rack the part F2 of the lever F, F2,
comes against the stud e³ and is depressed thereby and the piece E turned down
clear of the end of the part A of the rack so that when the pinion D engages with
this alone (after having drawn back all of the part B) the said part A. is drawn into
the part B so as to lie parallel therewith.
Gis a raised piece in the part B for the part A to run on and give a space in
which the piece E can be clear of the end of the part A. The parts A and B are
shewn as being made girder fashion but they can be made in any other way, and
the projecting and recessed portions ƒ and g of the parts A and B where they
engage together may be inclined as shewn, or straight as desired.
His a friction roller carried on levers I and counterbalanced so as to support the
racks A and B and maintain them in gear with the pinion D the front of the
part B being inclined to depress the said roller from out of the path of the said
part B.
The roller H is not essential. It may be replaced by a roller fixed on the bed
plate C or carried by the end of the rack B. Although I have described with
reference to the accompanying drawings a rack made in two longitudinal portions
only yet it is to be understood that a rack may be similarly made in more than two
longitudinal portions by simply duplicating the parts so that after the first and
second parts are operated as described the second part is locked with a third part
and if required this third part with a fourth part and so on, and on the return of
the rack the parts will be released and telescoped into or caused to lie side by side
of each other in substantially the same manner as that described with regard to the
locking, unlocking, extention, and telescoping of the two portions.
In racks thus made in more than two longitudinal parts the pins or stud pieces
for working the levers of the piece E of the first portions may be carried by
projections from the latter portions of the rack the projections supporting the pin
or stud for operating the first and second parts being carried by the third and that
for operating the second and third being carried by the fourth part and so on for
as many lengths as there may be.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is.
First Forming racks for transmitting motive power, in longitudinal parts
capable of being operated so that a part or parts is or are moved into or beside the

page_text: other part or parts and is or are protruded therefrom, the said parts being capable
of being locked together and released from each other substantially as and for the
purpose described.
Second. The arrangement and combination of parts constituting the rack as
herein before described and illustrated by the accompanying Drawings.
Dated this 6th day of November 1884.