AN IMPROVED CONSTRUCTION OF RACK FOR MECHANICAL PURPOSES
Year: 1881

page_text: LETTERS PATENT to William Prowett, of Birmingham, in the County of
Warwick, Gentleman, for an Invention of "AN IMPROVED CONSTRUCTION
OF RACK FOR MECHANICAL PURPOSES."
PROVISIONAL SPECIFICATION left by the said William Prowett at the
Office of the Commissioners of Patents on the 7th January 1881.
WILLIAM PROWETT, of Birmingham, in the County of Warwick, Gentleman.
"AN IMPROVED CONSTRUCTION OF RACK FOR MECHANICAL PURPOSES."
This Invention consists in constructing racks with loose teeth, that is, with
teeth pivotted or otherwise jointed to the rack, these teeth being so formed that
when the rack has a forward motion imparted to it they will stand rigidly in
position and work into the cogs of any wheels desired to be set in motion; but
when the motion of the rack is reversed the teeth will be closed up and out of use.
Thus each forward movement of the rack will set the teeth in action, the reverse
movement withdrawing them ready for the next stroke.
"
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Prowett in the Great Seal Patent Office on the 6th July
1881.
WILLIAM PROWETT, of Birmingham, in the County of Warwick, Gentleman._
AN IMPROVED CONSTRUCTION OF RACK FOR MECHANICAL PURPOSES."
This Invention consists in constructing racks with loose teeth, that is, with teeth
pivotted or otherwise jointed to the rack.

page_text: These teeth being so formed that when the rack has a forward motion imparted
to it they will stand rigidly in position and work into the coge of any wheels
desired to be set in motion; but when the motion of the rack is reversed the teeth
will be closed up and out of use.
Thus each forward movement of the rack will set the teeth in action, the reverse
movement withdrawing them ready for the next stroke.
I will now proceed to describe my Invention more fully in detail with the
assistance of the Drawings hereunto annexed; as already stated it refers to the
construction of an improved form of toothed rack intended to gear into a pinion or
toothed wheel, which it is either to drive or to be driven by, as the case may be,
and it consists in attaching the teeth to the frame or bar of the rack in such manner
that they will gear into the pinion or wheel in one only of its alternating motions,
and be free or out of gear in the contrary motion.
to it they will stand rigidly in position anu WULK
desired to be set in motion; but when the motion of the rack is reversed the teeth
will be closed up and out of use.
Thus each forward movement of the rack will set the teeth in action, the reverse
movement withdrawing them ready for the next stroke.
I will now proceed to describe my Invention more fully in detail with the
assistance of the Drawings hereunto annexed; as already stated it refers to the
construction of an improved form of toothed rack intended to gear into a pinion or
toothed wheel, which it is either to drive or to be driven by, as the case may be,
and it consists in attaching the teeth to the frame or bar of the rack in such manner
that they will gear into the pinion or wheel in one only of its alternating motions,
and be free or out of gear in the contrary motion.
DESCRIPTION OF THE DRAWINGS.
Figure 1 represents the rack in gear.
Figure 2
Figure 3
Figure 4
the same out of gear.
"
"
a modified form of the rack in gear.
the same out of gear.
"
In the Drawings (a, Figures 1 and 2) shew the frame or bar of the rack; (b) the
teeth, which are pinned or pivotted at the top end of each to the frame or bar in
such manner that they will be rigid to gear into the teeth of the pinion (c) in one
direction only of the rack's traverse, as shewn in (Figure 1), whilst they will be
free from the pinion and out of gear with it when travelling in a reverse direction,
as seen in (Figure 2).
(Figures 3 and 4) represent a modification of the rack in which the entire series
of teeth are so arranged upon a frame or bar (d) that the toothed piece (e) is brought
into or out of gear with the pinion (f) by means of the oblique action of short
levers (g) pinned to a second bar (h), the operation of these parts will be readily
understood on reference to the Drawings which shew the several parts in and out
of gear.
Having thus described the nature of the said Invention, and the manner in
which the same is to be performed, I claim,—
The improved construction of toothed rack, in which the teeth of such rack are
out of gear with those of the pinion or toothed wheel in one direction of its traverse,
as herein more fully set forth and specified.
In witness whereof, I, the said William Prowett, have hereunto set my hand
and seal, this Fourth day of July, in the year of our Lord One thousand
eight hundred and eighty-one.
Witness,
H. C. SCOLLICK,
19, Villa Road,
Brixton,
Cashier, Bank of England,
London.
WILLIAM PROWETT. (L.S.)