Improvements in and relating to Rack and Pinion Gearing.
Year: 1892

page_text: Comp ete Specification Left, 12th Aug., 1892-Accepted, 8th Oct., 1892
COMPLETE SPECIFICATION.
Improvements in and relating to Rack and Pinion Gearing.
I, FRANKLIN PIERCE HUMMEL, of Blissfield, County of Lenawee, and State
of Michigan, United States of America, Mechanic, 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:-
My invention relates to a mechanical movement, and has especial relation to that
branch of the art in which a minimum amount of power is required to perform a
maximum amount of work.
The invention more especially relates to a mechanical movement which is
designed to be placed between the point of power and the point of application.
The object of the invention is to provide a mechanical movement of few parts,
and of few wearing points that shall attach to the point of power and either
decrease the amount of power required to perform a certain work or to increase
the power at the point of application of the device to perform an increased amount
of work.
With these objects in view the invention consists in the parts and combination of
parts of a mechanical movement as will be hereinafter shown in the drawings,
described in the Specification and pointed out in the claims.
In the drawings I have shown the movement as applied to an engine, it being
apparent that I may also employ the same to any device or mechanism where the
power is employed to perform the work, without departing from the spirit of my
invention.
In the drawings:
Figure is a side elevation of an engine constructed in accordance to my
invention.
Figure 2 is a longitudinal vertical section of the same showing its internal
working parts.
Figure 3 is a transverse section on lines x-x Figure 1.
Figure 4 is a detail view of the jointed steam pipe for supplying the steam
chest.
1 designates the foundation of the engine on which rests the bed 2, which is
constructed with guides 3, extending its entire length on which slides the cylinder
bed 4, one end of which is secured to the cylinder 5, by means of lugs or arms 6,
said bed 4, having guides 7 extending its entire length on which works the piston
slide 8.
On the opposite end of the cylinder bed 4 to that on which the cylinder is
secured is attached the pitman rod 9, leading to any device or mechanism to be
operated.
10 designates a rack bar, either integral or attached to under side of the piston
slide 8, and 11 designates a similar rack bar secured to the foundation 1, there
being a pinion 12 journaled on shaft 13 secured in the cylinder bed 4, said pinion
running in slot 14 in the bed plate.

page_text: 15 designates the piston rod, one end being securely attached to the piston slide
by means of nut 16, on an integral bolt or bearing 17, the opposite end of the
piston rod carrying a piston head 18, the cylinder, steam chest 19, and interna!
working parts being of any preferred form and not a part of this invention need
no further description.
20 designates a pipe one end being pivotally secured to the entrance port of the
steam chest, the opposite end being pivotally secured to a pipe 26 at which point the
steam chest 21 is attached, said pipe 20 having a steam tight joint 211, for a
purpose to be hereinafter explained.
22 designates a longitudinal arm, secured to a lug on the cylinder bed 4, on
which arm works a slide 23, to the upper side of which is securely attached the
valve rod 24.
25 designates a lever connecting the slide 23, and section 26 of the jointed steam
pipe, the steam will enter one of the ports of the cylinder (the ports are not shown
or explained in detail as they are the ordinary or any preferred form as has been
described) moving the piston head 18 either forward or backward as the case may
be and also the piston rod 15, and consequently the piston slide 8, the rack bar 10
of which by meshing with the pinion 12 will revolve the pinion, which engaging at
its lower side with stationary rack bar 11, will cause the pinion and consequently
the cylinder bed 4 in which it is journaled to move forward the same distance as
the piston stroke.
This operation will cause the section 25 of jointed pipe 20 to also move forward,
that is the upper end of the same, the lower end being stationary and working on
a pivot, which forward movement will cause the slide 23 to move forward by means
of a lever connecting it and the upper end of section 26 of the pipe 20 until the
full stroke of the piston is made, when the opposite port of the valve chamber will
be opened and the operation will be reversed and continued.
It will thus be seen that the cylinder bed 4, carrying the pitman, will make the same
length of stroke as the piston rod 15, but the piston rod 15 will move forward the
same length of stroke as the cylinder 5, also the distance the cylinder bed 4 moves as
it travels therewith, the cylinder being secured thereto without variation of steam
supply to the cylinder; it will further be seen that by the loss of motion in the
movement of the cylinder with the pitman, the same amount of steam yields a
greater power than with the direct acting engine, by reason of the pinion 12 which
not only acts to increase the leverage, the lower rack bar acting as a fulcrum, and
the upper rack bar as a power, the shaft 13 being the weight and on the principle
of a lever, the amount of power applied at the upper end will be increased at the
point of weight or on the shaft 13 and consequently on the pitman, and that by
having a moving fulcrum I do away with the friction and overcome any dead
center.
It will also be seen that I may use the same for an electric motor, by placing
the motor where I have the steam cylinder, it being understood that my mechanical
movement is applied as an intermediate device, between the power and application.
It will also be seen that I do away with the wear on the piston, by securely
attaching the same to the piston slide.
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. In a mechanical movement, an upper movable piston slide provided with a
rack bar, a lower stationary rack bar, and a cylinder bed movable between the two,
and a pinion carried thereby engaging the rack bars.
2. In a mechanical movement, an upper piston slide provided with a rack bar, a
lower stationary rack bar, and a bed intermediate the two, a pinion carried thereby
and engaging the rack bars, a power device upon the bed, and a piston rod con-
necting the same and the piston slide.
3. In a mechanical movement, a power device; a piston and rod, a piston slide

page_text: attached thereto, and provided with a rack bar, a lower stationary rack bar, a
cylinder bed intermediate the two and provided with a pinion meshing with the
two rack bars, said intermediate cylinder bed being connected to the device to be
operated.
4. In a mechanical movement, an upper piston slide, a rack bar secured
thereon, a lower stationary rack bar, an intermediate cylinder bed, a power device
secured thereon, and means for applying the power to the upper piston slide, a
pinion meshing with the two rack bars, and means for connecting the intermediate
cylinder bed with the device to be operated.
Dated this 29th day of July 1892.