Improvements in and relating to Rack and Pinion Gearing.
Year: 1890

page_text: Date of Application, 22nd Aug., 1890-Accepted, 27th Sept., 1890
COMPLETE SPECIFICATION.
Improvements in and relating to Rack and Pinion Gearing.
A communication to me from abroad by JAMES MOAT LOCKEY, of Faulkton, in the
State of South Dakota, one of the United States of America, Mechanic.
I, EDMUND EDWARDS, of the firm of Edwards and Co., Patent Agents and Engineers,
of 35, Southampton Buildings, Chancery Lane in the County of Middlesex, do hereby
declare the nature of the invention and in what manner the same is to be performed.
to be particularly described and ascertained in and by the following statement and
accompanying drawing, that is to say :—
My invention is an improved pitman which has continual draft at extreme distances
from the centre, and is always in full power, as it has no dead centre, and is therefore
always ready to start by one cylinder or piston-rod, and the invention consists in certain
novel construction and combination of parts, as will be hereinafter described and
mentioned in the claims specified.
Figure 1, is a longitudinal vertical section of my improved pitman at the "
position.
Figure 2, is a like view at the "push" position.
Figure 3, a top view or plan of pitman and connection.
Figure 4, is a section of the same on line 4 4 of Fig. 3.
Figure 5, is a detail of the guide plate or rail, in perspective.
pull"
may
In carrying out my invention, I support the shaft A, in suitable bearings so it
rotate. Obviously said shaft may be used for operating driving wheels or pulleys or
any other similar purpose, as may be desired. The shaft is provided with a toothed
wheel B. Manifestly the provision of this wheel on the hub, or otherwise fixed to the
wheel to be rotated would involve no departure from the broad principles of my inven-
tion, but I prefer to support it on the shaft, and to secure it thereon in the manner
which I will now describe.
On the shaft, I secure a fly wheel C, and alongside said fly wheel, I journal loosely
on the shaft, a disk D. On the opposite side of disk D, from pulley C, I place a small
washer d, up against which the toothed wheel B, is fitted, such wheel being so formed
as to turn freely on the shaft when not clamped, in the manner presently described.
On the side of wheel B, opposite washer d, I support a washer e, and disk E, similar
to d, and D, and the fly wheel F, is threaded on the shaft so it can turn up against
the centre portion of disk E, and so serve to clamp the parts E, e, B, d, and C, tightly
together.
The disks D and E, are made of equal diameter, and of greater diameter than the
toothed wheel B, so they will serve as keepers for the pitman head.
The pitman G, which may be reciprocated in any suitable manner, has its heap
bifurcated, forming the upper and lower toothed arms H, I, which fit between the
disks D and E, above and below the wheel B, and engage said wheel alternately as the
pitman is reciprocated, the upper arm having a drawing or pulling engagement with
the wheel and the lower arm a pushing engagement therewith, as will be seen.
It will be noticed that the teeth of the upper arm are inclined back from the outer
end of the pitman head, while the teeth of the lower arın incline forward to said end,
so such teeth may better draw and push upon the toothed wheel, as will be understood
from the drawings.
"
Now, if as the pitman is reciprocated, its upper and lower arms be caused to engage
the diametrically opposite sides of the wheel B, it follows that the said wheel and the
shaft or other parts connected therewith will be rotated continuously in one direction.
To secure the proper engagement of the upper and lower arins with the wheel, the
pitman is provided with a lateral lug or projection J, which rides above and below a
guide rail or plate K, as shown, the ends of said lug and rail being properly bevelled
to better guide the lug above and below the rail.

page_text: The plate K, is supported on an upright plate or web K', having a foot piece K²,
bolted or otherwise secured to the framing, the parts K, K, K2, being preferably
formed integral, as shown; the plate K, projecting laterally from the upper edge of
plate K, and foot K2, projecting laterally from the edge of said plate K¹, and in an
opposite direction from plate K.
On its backward motion the pitman moves with its upper arm in engagement with
the wheel, and its lug under the guide plate; while in its forward movement it moves
with its lug above the plate or rail and its lower arm moves with its lug above the
plate or rail and its lower arm with the wheel B.
To adjust the lug above the rail at the forward end of the pitman stroke, I provide
the pitman with an inclined bearing surface L, which engages a bearing M, on the
frame and throws the pitman head and its lug up at the inner end of the stroke, just
as the lug clears the end of the rail or plate, so that on the return movement of the
pitan, the lug will travel along the upper side of the rail until it passes the end
thereof next the wheel B, when the head will drop to bring its upper arm in engage-
ment with the wheel B, and the pitman will start on its return movement. Manifestly,
the bearing M, might be inclined instead of the bearing L, or both bearings might be
inclined as an equivalent to the inclining of bearing L, as shown.
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-
1. An improved pitman having its head formed with upper and lower arms toothed
on their adjacent faces and arranged to engage the diametrically opposite edges of the
same wheel in reverse movements of the pitman, substantially as set forth.
2. The combination of the toothed wheel, the pitman having its head formed with
upper and lower toothed arms arranged to alternately engage the opposite sides of said
toothed wheel, and devices by which the said arms may be alternately held in engage-
ment with the wheel, substantially as set forth.
3. The combination of the wheel and pitman having arms arranged to alternately
engage the opposite sides of said wheel as the pitman is reciprocated, substantially as
set forth.
4. The combination of the toothed wheel, the disks on opposite sides of said wheel
and arranged to project to form keeper flanges alongside the wheel, the pitman having
its arms toothed to engage the wheel and alternately engaged with the opposite sides
thereof, as the pitman is reciprocated, substantially as set forth.
5. The combination of the shaft, the fixed fly wheel on the shaft, the disk D, the
toothed wheel, the disk E, the fly wheel threaded on the shatt up against the disk E,
the pitman having upper and lower arms arranged to alternately engage opposite sides
of the wheel as the pitman is reciprocated, and devices by which said arms may be
alternately held in engagement with the wheel, all substantially as set forth.
6. The combination of the wheel, the pitman having arms engaging opposite sides
of said wheel and provided with a lug or projection J, and the guide rail or plate K,
arranged to receive the bearing of the said lug, substantially as described, whereby the
arms of the pitman may be alternately held in engagement with the wheel, as and for
the purpose set forth.
7. The combination of the toothed wheel, the pitman having arms arranged to
alternately engage opposite sides of the wheel as the pitman is reciprocated, the guide
plate K, the lug J, on the pitman arranged to bear above and below said rail in the
reverse movements of the pitman, and a bearing M, arranged for engagement by the
pitman, substantially as and for the purposes set forth.
₫ this 21st day of August 1090.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.