Improvements in Steam, Gas, and other Engines.
Year: 1897

page_text: Date of Application, 23rd Feb., 1897-Accepted, 1st May, 1897
Improvements in Steam, Gas, and other Engines.
1, CHALMER MORROW CINCINNATUS PRENTICE, of 4670 Lake Avenue
Chicago, in the County of Cook, and State of Illinois, United States of America,
Physician, 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 engines of the class having a reciprocating piston and a
piston rod operatively connected with a crank or eccentric, and my invention is
applicable to steam, gas and other types of engines in which a piston is made to
reciprocate within a cylinder by the expansive force of a vapor, a gas, or gases, and
may be applied also to explosive engines in which the piston is moved by the impact
of the explosion.
The general object of my invention is to secure a higher efficiency in proportion
to the cost than has heretofore been obtained. I attain this object by a construction
which permits of the utilization of the moving force at such times as render it
effective, and my construction involves in its broadest scope the application of the
motive power within a restricted area and at such point in the working cycle of the
engine as will give the piston great leverage upon the driven crank.
To accomplish this I so construct the cylinder that it is caused to move with the
piston during the initial movement of the latter from either or both of its limits.
After the cylinder and piston have moved either separately or simultaneously
together through a portion of the stroke, the cylinder is then locked by appropriate
mechanism against a return movement due to recoil and the motor fluid is admitted
behind the piston and permitted to expand within a chamber of comparatively
small area.
The admission of the motor fluid is timed so that it exerts its force
upon the piston to drive it forward at a point when the crank is in an effective
position for the application of power thereto; that is to say, at a point between
its dead centres and preferably when it is midway or substantially midway between
its dead centres. The motor Huid being thus limited to a chamber of small area
exerts its initial force upon the piston at the time when the crank is in an
advantageous position for the application of power. When the piston has
completed its travel, the cylinder is unlocked and the momentum carries the crank
over its dead centre and toward a second effective position attained by it during its
revolution. During this action the cylinder is again caused to travel in the
direction of the stroke of the piston during the initial part of the return stroke of
the latter, and as the crank approaches its second position of high efficiency the
cylinder is again locked against recoil and the motor fluid admitted, operating, as
before, by its initial pressure at ibe effective point of the revolution to complete the
return stroke of the piston. In this method of operation the motor fluid being
confined within a small area exerts its initial force as before stated at the time
when the crank is in the best position for the application of the effective force
and the motor fluid also works expansively until the piston completes its
stroke.
It will be seen from the foregoing that my invention, so far as relates to the
structural features, covers in its broadest scope a reciprocating piston co-operating
with a movable cylinder and suitable mechanisms for moving, locking and unlocking
the cylinder.

page_text: In the accompanying drawings I have illustrated diagrammatically an embodiment
of my invention without attempting to illustrate all the details which latter can
readily be supplied by persons skilled in the art to which my invention
appertains.
Figures 1 to 8 inclusive are broken elevations, partly in section, each showing a
frame in which the cylinder reciprocates, the piston being indicated by dotted lines
and the piston rod broken away, the crank shaft showing in section and a crank
and cams for operating the locking and unlocking mechanisms in elevation. The
parts shown in the several views will be more particularly referred to in connection
with said views respectively.
Figure 9 is a detail in section through the piston rod, and showing certain
mechanisms mounted thereon and associated therewith, and
Figure 10 shows a construction wherein the locking and unlocking mechanisms
are simplified.
15 represents a frame work, shown in section in the several views, (1 to 8
inclusive), and 16 a frame work attached thereto and shown in full lines. The
frame work 15 is hollow and of such interior configuration as to adapt it to enclose
the cylinder 17 and the valve chest or valve containing mechanism for controlling
the admission and exhaust of the motor fluid. Said frame work will also be
adapted to provide ways in which the cylinder 17 may slide, the travel of the
cylinder being, in the illustration shown, somewhat less than the length of the
cylinder itself. 18 indicates the piston, and 19 the piston rod. 20 represents
the crank pin, 21 the crank, and 22 the crank shaft.
In general construction, the cylinder, piston and piston connection may be as
usual. The means for controlling the admission and exhaust of the motor fluid are
not shown, but the admission ports in the cylinder are indicated at 23, and one of
the corresponding ports in the casing or frame 15 is indicated at 24, it being
understood that a second similar port is provided in the casing but which is in
register with one of the ports 23 in the several views, and hence not shown. The
exhaust ports are indicated at 25.
The locking, unlocking and holding mechanisms for the cylinder may be of any
desired construction, and the mechanisms shown are intended as suggestive or
indicative merely. These several mechanisms may be operated from cams on the
crank shaft 22, and I have shown upon said crank shaft a cam having three
grooves.
In Figures 1, 2, 7 and 8, 26 is a cam groove which is made to operate a sliding
frame 27 through the intervention of the pitman or bar 28 having a stud working
in the groove. Said sliding frame is made to operate bell cranks 29 pivoted on the
stationary frame 15 and pivotally connected with locking dogs 30, said locking
dogs working in apertures in the frame 15 and being adapted to project into the
hollow or chamber thereof and in position to form an abutment or stop to prevent
the recoil cf the cylinder when in the position shown in Figures 1 and 8, while in
Figures 2 and 7 said locking dogs are shown as withdrawn so as to permit of the
travel of the cylinder with. the piston.
It will be observed that these locking dogs are effective when the cylinder is at
the limit of its outward movement or at the conclusion of its movement away from
the crank shaft. Now in order to lock the cylinder when it is at the opposite
limit of its travel or at the inner end of the frame, a second set of locking dogs are
employed connected to a second frame and operated by a second cam groove,
marked 31, (Figures 3, 4, 5 and 6), the pitman co-operating therewith being
marked 32 and the frame 33, the bell cranks 34 and sliding dogs 35. These
mechanisins operate in due order and sequence to lock and unlock the cylinder and
are so timed as to effect this locking and unlocking with due relation to the
admission of the motor fluid to the interior of the cylinder as will be hereinafter
described.
The mechanisms for effecting the movement of the cylinder may also be of any
desired or appropriate construction. The means which I have selected for

page_text: illustration operate to lock the cylinder to the piston rod so that the movement
of the cylinder is effected by the piston rod, and the movement of the latter is due
to momentum. Said locking means comprise a yoke 36 which has mounted so as
to rock therein a collar 37, shown in the detail Figure 9 surrounding the piston
rod. Said collar bas two notches in its perimeter located opposite each other, and
marked 38. The piston rod carries two sets of pins 39, 40, said pins being of such
size and length as to pass through the notches or slots 38 when the collar 37 is
turned so that the positions of the slots and pins register. The collar 37 has an
off-standing lug 41 on its periphery which slides in a slot 42 in a sliding frame 43, the
latter being reciprocally mounted in the frame 16. Said frame 43 is reciprocated
by means of a walking beam 44 having a pin 45 at its outer end working in a cam
groove 46 in the can wheel carried by the crank shaft. Any other suitable
mechanism may be employed for locking the cylinder aud piston rod.
Now by referring to the drawings it will be seen that said cam is of such
configuration that the walking beam 44 will be vibrated four times during each
complete revolution of the crank shaft, thereby locking and unlocking the cylinder
and piston rod in its two extreme positions during each rotation of the cam.
In the position shown in Figure 1 the cylinder is disconnected from the piston
rod, and in Figure 2 the high side of the cam having tilted or vibrated the walking
beam and depressed the frame 43 the collar has been turned into the position shown
in Figure 9, thus bringing the pins 39 into position to engage the collar so that as
the piston is carried by momentum over the dead centre in the direction of the
arrow in Figure 2, it will cause the cylinder to travel with it toward one end of
the frame and as the cylinder reaches the inner limit of its travel the configuration
of the cam permits or causes the return of the sliding frame and the unlocking of
the cylinder from the piston rod, which position is about to be attained in Figure 3
and is shown attained in Figure 4.
During the next quarter of the stroke the two sets of Jugs or pins on the piston
rod both pass through the collar, as shown in Figure 5, and as the crank reaches
the outer dead centre point the inner set of pins are in position to engage with the
collar so as to again lock the frame connected with the cylinder to the piston rod.
As the crank proceeds through the third quarter of the revolution to the positions
indicated in Figures 7 and 8, the cylinder is moved to the outer limit or returned
to the position shown in Figure 1, and at the completion of the revolation of the
crank the collar is in such position that the lugs on the piston rod have passed
through as the piston is driven by the expansive force of the motor charge to the
limit of its stroke.
It only remains to state the order of the admission of the motor fluid, the locking
and unlocking of the cylinder and the relative positions of the crauk during the
working cycle of the engine.
Starting again with the position shown in Figure 1, it will be seen that the
crank is approaching its dead centre nearest to the cylinder and that the latter is
locked while the piston is nearing the outer limit of its stroke, working under the
expansive force of the motor fluid or under the effect of impact. In Figure 2
the locking dogs 30 are withdrawn leaving the cylinder free to be moved with the
piston when the latter begins its return stroke, the pins 39 being in position to lock
the cylinder to the piston rod, as shown in Figure 2. From the position shown in
Figure 2 toward the position shown in Figure 3, the cylinder and piston are moved
simultaneously by momentum. In Figure 3 the cylinder is about to be unlocked
from the piston rod and is in position to be locked against recoil. In Figure 4 the
cylinder is locked against recoil and the piston is free to travel independently of
the cylinder. Further the ports are in such position as to admit steam behind the
piston, which is near the end of the cylinder head, leaving a working chamber of
small area.
The initial pressure of the motor fluid is exerted upon the piston, and
by reference to Figure 4 it will be seen that the crank is in an effective position
for utilizing this initial pressure; that is to say, it is at a point between the dead
centres and the leverage is great.

page_text: I have demonstrated approximately that a body of steam of, say-a half inch to
an inch following the piston, will exert in this position of the crank, as great a
pressure as eight to sixteen times that body would give in the ordinary cylinder
having say, a sixteen inch stroke-and this results from the fact that in an engine
of the ordinary construction, having a stationary cylin ler and a reciprocating
piston, it will require a body of steam, where the piston has a sixteen inch stroke,
of-say-eight inches linear measurement, to drive the piston from the dead centre
to the point of greatest efficiency of the crank, or, in other words, to the point
where the initial pressure of the steam is most efficiently exerted upon said crank.
In the position shown in Figure 5 the piston has nearly completed its instroke, and
in Figure 6 the stroke is completed and the cylinder is unlocked. From the
position shown in Figure 5 to that shown in Figure 7 the piston and cylinder are
driven together by momentum toward the original position, being in the position to
be locked in Figure 7 and shown locked in Figure 8, and again ready to receive
the motive fluid.
In my construction, as in the usual construction, the piston moves with some
slight friction within the cylinder, particularly where the motor fluid work-
expansively, as in the case of steam, and this friction will be used in assisting t
cause the travel of the cylinder with the piston, and in order to avoid loss of power
the cylinder will be so mounted in its ways as to slide with very little friction. Its
bearings may be constructed, therefore, in any approved way to avoid excessive
friction.
I wish it to be understood that the particular mechanisms which I have herein
illustrated and described are intended to represent only one of the many practical
embodiments in which the underlying principle of my invention may be used, and
that therefore I do not limit my invention to the structural features shown and
described, but intend in the claims hereinafter made to cover not only the particular
means shown for causing the travel of and holding the cylinder, but all other means
operating to attain these results.
As showing some of the many modifications which may be made in the structural
details of this invention I will now refer briefly to Figure 10 wherein the
mechanisms for moving and locking the cylinder are somewhat simplified.
In this construction, the crank shaft 22 carries a single cam in which a single
cam groove is made to operate the locking and releasing mechanism. As shown in
this figure the locking dogs 30 and 35 are provided with racks on their inner edges,
which said racks are traversed by rotating gears 47. Said gears have pinions 48
which are driven by rack segments 49 on yoke arms 50. The stem of said yoke
carries the pin 51, which traverses the cam groove 56. Said cam groove is of
irregular form having four high points which are marked respectively 52, 53, 54
and 55 and which come into successive action during the rotary movement of the
crank. The parts are shown in Figure 10 in the same corresponding position as
similar parts in Figure 1. That is to say the piston has just completed its out
stroke and the cylinder is in position to be locked with the piston rod. This
locking is also effected by another construction of mechanism. The cylinder is
provided with rigid arms 57 which carry sliding locking dogs 58 normally thrust
out by the springs 59 and having wedge shaped openings therein as shown at 60.
Stationary wedge pointed blocks 61 are mounted upon the frame of the engine and
as the cylinder reaches the limit of its traverse in either direction the points of said
blocks 61 will enter the wedge shaped openings of the locking dogs 58 and thereby
lift them. The piston rod is provided with notches or seats 62 to receive the ends
of the locking dogs 58 and said dogs will engage under the action of their springs
and will be released by the action of the wedge shaped blocks 61 at proper
intervals. In the position delineated in Figure 10 the dogs are released but two
of them are nearly in position to enter their seats 62. When they have so entered.
the crank passing from the position shown through the first quarter of it.
revolution, will carry the cylinder and piston back together and at the end of said
stroke the blocks 61 will disengage the locking dogs, and the piston rod being

page_text: released and the port open, the piston will be driven back through the next
quarter of the stroke by the expansion of the steam. Locking dogs 30 and 35 are
cperated in due order and relation by the pin 51 passing over the high points 52,
53, 54 and 55 successively.
My invention may be said broadly to consist in a system in which the cylinder is.
movable and in which the piston has a reciprocating movement relative to the
cylinder, and in the employment of a movable cylinder and reciprocating piston-
and means for admitting the motor fluid to the cylinder when the piston is in a
position for effective work upon the crank shaft.
As above stated, my invention is applicable to steam, gas or other motor fluids
working by expansive force, and it may also be used in connection with explosive
mixtures which work properly speaking by impact rather than by expansion.
Further, it will be understood that the time of the actions of the various
mechanisms may be changed. For example, I have described an arrangement
whereby the motor fluid is admitted to the cylinder when the crank is about midway
between its dead centres, and I believe that at substantially this point the crank is
in the most effective position for work, but I wish it to be understood that the
motor fluid may be admitted advantageously at any point between the dead centres..
All these variations 1 consider within the scope of the general principle of my
invention above stated.
I have shown the mechanism so arranged that the cylinder and piston move
simultaneously toward the point of admission of the motor fluid, but obviously the
piston might be moved in advance of the movement of the cylinder, the movement
of the latter being faster than that of the piston. Further, instead of locking the
cylinder and piston together during the movement of the former, the cylinder
might be moved entirely independent of the piston and its rod and the relative
length of movement of the piston and cylinder, as well as the size or area of the
chamber into which the motor fluid is admitted, may be varied at will.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. An engine having a movable cylinder with fixed heads, a piston reciprocating
within the cylinder, mechanism substantially as described for moving the cylinder -
in definite relation to the piston movement, and mechanism for fixedly securing or
locking the cylinder at predetermined limits of travel, substantially as described.
2. An engine having a single bodily movable cylinder with fixed heads and a
reciprocating piston working within the cylinder, mechanism substantially as
described for moving the cylinder and piston from dead centre positions, means for
admitting the motive fluid to the cylinder and mechanism for locking the cylinder
against recoil whereby an added movement may be imparted to the piston by the.
expansion of the motive fluid behind it, substantially as described.
3. The combination with a stationary frame having suitable ways, a cylinder
mounted to slide in said ways, a piston reciprocating within said cylinder, means
for locking the cylinder and piston together whereby they are moved simultaneously
during the first part of the piston stroke, means for locking the cylinder against
recoil and for unlocking the cylinder and piston whereby to permit the piston to
continue its travel freed from its connection with the cylinder, substantially as
described.
4. The combination with a stationary frame having ways therein, of a cylinder
adapted to slide in said ways, a piston mounted to reciprocate within the cylinder
and having a piston rod, a crank shaft connection, means for locking the cylinder to.
the piston rod whereby the cylinder is caused to move with the piston during
the initial part of the stroke of the latter, means for locking the cylinder against
recoil and means for unlocking the cylinder from the piston rod and admission
ports in the cylinder adapted to admit the motor fluid when the crank shaft is.
intermediate its dead centres, substantially as described.

page_text: 5. The combination with a movable cylinder, of a piston adapted to move
therein and also independently thereof, a piston rod having locking projections
thereon, a collar encircling the rod and having grooves through which the locking
projections of the rod may pass, and means for rocking said collar whereby to turn
the locking projections out of register with the grooves and a connection between
the collar and the cylinder whereby the latter may be locked to and moved with the
piston rod, substantially as described.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Cena 10
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