IMPROVEMENTS IN SAFETY HY- DRAULIC LIFTS
Year: 1878

page_text: LETTERS PATENT to Cyrus Baldwin, of 67, Strand, in the City.of Westminster,
Mechanical Engineer, for the Invention of "IMPROVEMENTS IN SAFETY HY-
DRAULIC LIFTS.”
Sealed the 20th September 1878, and dated the 18th July 1878.
COMPLETE SPECIFICATION filed by the said Cyrus Baldwin at the Office of
the Commissioners of Patents on the 18th July 1878.
CYRUS BALDWIN, of 67, Strand, in the City of Westminster, . Mechanical
Engineer. "IMPROVEMENTS IN SAFETY HYDRAULIC LIFTS."
Certain of my improvements relate to that class of hydraulic elevators in which
the ram or piston is operated by variations of fluid pressure on one or both sides of
the piston or head, and more specifically to the construction of a double piston in
connection with other operative devices, whereby a double lifting power is secured
without increase of fluid pressure or of the diameter of the cylinder.
Certain other of my improvements relate to a new and improved shackel, clevis,
or fastening for securing a wire rope or cable, whereby a very secure fastening is
obtained, and one which may be easily and quickly made and unmade.
Certain other of my improvements relate to a new and improved safety attach-
ment for elevators, which shall obviate the danger of accidents and loss of life
which has hitherto existed. They consist in so combining two or more ropes with
an elevator car, cab, or platform, that if from any cause one rope ceases to bear its
proportion of the weight incident to raising the said car or cab the safety will be
rendered operative; and arrest the progress of the said car, cab, or platform.
In the accompanying Drawing,―
Figure 1 is a side elevation of an elevator embodying my improvements.
Figure 2 is a sectional elevation on a larger scale of the cylinder,, piston valves,
and connections shewn in Figure 1.

page_text: Figures 3, 4, and 5 are sectional elevations on a larger scale of the valve shewn
in Figures 1 and 2.
Figure 6 is a side elevation of my improved safety attachments, and Figure 7 an
end elevation thereof.
Figure 8 is a view showing my improved shackel or clevis.
Figure 9 is an inverted plan of the piston shewn in Figure 2, and Figure 10 is a
sectional elevation thereof.
Similar letters of reference designate corresponding parts in all the Figures.
I designates the elevator, car, cab, or platform, which slides vertically along guides I'
on each side of the hoistway. To this car, cab, or platform are attached ropes R, which
pass over the pulley or wheel W in the usual way, and thence any desired number
of times around the fixed and movable pulleys or sheaves W¹, W2, (of which more
or less may be used, as desired), and their ends are made secure at R. The movable
pulleys W³, are connected by a stirrup p with the double piston stem B³, which
latter, passing through stuffing boxes b into the cylinder A, is connected at its
opposite end with the double piston B, B'. The cylinder A is made in two parts,
or is divided into two compartments or chambers a, a', by means of a transverse
diaphragm a² at or about midway between its two ends. The pistons B, B¹, play
one in each chamber. The stem B2 plays through a stuffing box b¹, and in the
diaphragm I make a port c, opened and closed by any suitable form of valve c¹.
Supply and discharge A', A2, are made at or near the ends of the cylinder A.
The valve case D has a valve chamber d, preferably of cylindrical form, and by
preference lined with lining d¹, and in such lining I make perforations d² covering
the ports e, e¹, e². The port e has a pipe communication P with the cylinder port A
The port e' by a pipe or passage P₁ communicates with a cylinder port as at or near
the upper end of the chamber a', and the port e² is connected by a pipe P² with the
cylinder port A².
In the valve chamber D I arrange a series of disk-shaped valves S, S¹, S², on a
common stem S³. These valves are provided with suitable packing, preferably cup
packing, and the stems project outside of the valve case, so that the valves can be
Water under
shifted by rack and pinion i, or in any other suitable manner.
pressure is admitted at m from any suitable head or source of supply.
The valves in the valve case D receive their motion through a rack and pinion i
from an operating wheel G, or any other equivalent device capable of being moved
so as to properly shift the valves by the use of an operating cord in the car, or
other known means adapted to the like end.
A hand hole h covered by a cap is provided in the side of the cylinder A near the
diaphragm a² for convenience in packing the stem B' and the piston head B. The
lower open end of the valve chamber constitutes a waste port, as at d³. The appa-
ratus has also an open water passage or communication q from the chamber a near
the diaphragm a² to the chamber a¹ below or outside of the utmost point of motion
of the piston head B'.
When the operator in the car desires to raise the car while empty, or with only a
light load, he works his operating cord so as to bring the valves to the position
shown in Figure 2. Both chambers a, a', are presumed to be full of water under
pressure, as also the communicating pipes. Full water pressure will then be
effective on the upper side of the piston head B, and water below the piston head B¹
will flow out freely at 3. The valve S¹ prevents the supply from escaping at the
waste port. Water from below the piston head B will open the valve c¹ and flow
through the port c, so as to fill the space vacated by the piston B' as it moves
downward, the latter acting perhaps somewhat as a pump piston to draw. the
water through. The residue, any, of water under B will pass through q to the
waste port.
To work the apparatus with maximum effect in raising heavy loads the wheel G
is turned so as to shift the valves to the position shown in Figure 3. In this
adjustments the ports e¹ and e² are brought into communication, and water in the

page_text: pipe P (which is continually under pressure) is free to pass from port e³ through
between the valves S and S¹, through port e', and into pipe P¹, and by port a³ into
the upper end of the lower cylinder or chamber, and above the piston head B'.
Water pressure will then act effectively on top of the piston head B, as before; also
the water pressure entering at a³, as just explained, will close the valve C¹, and act
with its full force on the upper side of the piston head B', the water below B
escaping by q and d³, as before, and the water below B' escaping at d³ in both cases
without resistance. I thus get the effective force of the water pressure on two
cylinders instead of one, thus practically doubling the power of the apparatus.
To lower the car the valves are shifted into the positions shewn in Figure 4. In
this adjustment both valves S, S¹, are below the escape port, so that the waste is
entirely cut off; also both ports e¹ and e² are brought into communication with the.
port e. The car then being sufficiently heavy, or being counterweighted, comes
down by its own gravity. Water above the two piston heads flows by ports e³, el,
into the chamber at below the lower piston B', and a portion of it passes up q into
a space below the upper piston B.
By raising the valves a little the port e can be partially closed, and the circulation
of water from above to below the piston can thereby be so choked as to prevent a
too rapid descent of the car should such danger occur.
To stop the car at any time it is only necessary to bring the valves to the position
shewn in Figure 5. The waste or discharge is closed by the valve S, and the circu-
lation from above the pistons to below them is prevented by the valve S¹.
--
In all the adjustments described the valves are balanced as regards water pressure;
but if such balancing is not desired the valve S2 may be omitted, the end of the
valve chamber being closed by a cap made with a stuffing box for the valve stem
to play through.
As regards the passage P¹ and the port a³, and the manner of opening and
closing the latter, I do not intend to limit myself to the form of construction shown,
but in so far as the same is an element of the present improvement I include herein
any suitable water conduit communicating at one end with the water under.
pressure, and at the other with the chamber a' above the piston B¹, and provided
with any suitable form or construction of valve or cock, operated in any desired
way, for opening and closing such conduit. Nor by speaking of the upper and
lower sides of the piston heads do I intend to confine myself to a vertically arranged
apparatus, since the cylinder may be arranged horizontally, if so preferred. The
terms "upper" and "lower," "above" and "below," are used relatively.
.
It will also be observed that the chambers a, a', are in effect two cylinders fixed in
position in the same axial line, and if so prepared they may be arranged separately,
and so arranged relatively to each other. The stem B made a little longer will
then extend through a stuffing box in each contiguous cylinder head, and a suitable
water conduit with any proper form of valve will take the place of the diaphragm
port c so as to perform the same function. In such case the passage may have the
same lower terminus, as described, or a separate valve may be added for closing it
at the proper time. I might also use the same device and arrangement in general
if both cylinders were open at one end, and the water applied to only one side of
the piston, so that by forcing it up or down the necessary power might be commu-
nicated to the car, but I prefer to use water on both sides of the piston, so as to
utilize the full pressure at the point of discharge, and to have the water to act as a
brake in the descent of the car by passing it through a confined space to the bottom
of the piston.
:
Nor do I limit myself in either form of the Invention to. the use of pistons of the
same diameters, since they may be varied in this respect at pleasure, or according as
it may be desired that the additional piston should do more or less than double the
work of the first one; also by a duplication of the proper pipes and ports the skilled
mechanic can adapt the apparatus described to three or more like cylinders and.
pistons, and such feature is hereby included within the present Invention.
".
.

page_text: The object of my improved safety attachment is to provide for arresting the fall
of the car in case of either or both of the suspensaries breaking, and thus preventing
accident and loss of life.
.
"
..
My car is shown as resting upon a plank or timber I³ constituting the safety.
This plank is represented as having in its ends recesses or notches which embrace
the slides I, and by which the car is guided and kept in position at the bottom.
These recesses or notches are wider than the slides I', and carry in them wedges or
keys C, C, which rest on-shoulders near their tops, parallel with and arranged in
bearings f, underneath the plank 12. I place a shaft or bar E, whose ends are pro-
vided with projecting fingers E¹, having one or more points which are in close
proximity to the slides I, and which rest immediately under the ends of the wedges
or keys C, C, which project below the lower surface of the plank I².
Pivoted underneath and near the ends of the safety plank or timber. I² are two
bell-crank levers H, H', which are held in proper position by a cross rod J running
from one to the other, so that, a movement of one of the said bell cranks will cause
a simultaneous movement of the other. The arms of these bell cranks H, H¹, are
kept in a horizontal position by the cross rod J, and project underneath the fingers
or points E', and holds them in position.
To the horizontal arm of the bell-crank lever H is attached a rod K, which passes
up the side of the car and is connected to a cross bar L at one end. A similar rod
Kis rigidly fastened to the opposite end of the safety plank or timber I³, and
passes up the side of the car to the other side of the said cross bar L. Attached to
the arm of the bell-crank lever H¹ is a similar rod M, which passes up the side of
the car, and is connected to one end of a cross bar L'. A similar rod M' is rigidly
fastened to the other end of the safety plank or timber I', and passing upwards is
connected to the opposite end of the cross bar L'; to the cross bars L, L', are
attached the suspensaries 7, 1. An equal draft exerted on each of the said suspen-
saries or cables 1, 1¹, serves to hold the arms of the bell-crank levers H, H', in such
position as to allow the points of the fingers. E¹ to rest at about 20° below the center
of the finger shaft E and to clear the slides.
If the suspensary / be broken it releases the cross bar L and bell crank H. The
whole weight of the car being thrown on to the cross bar L₁ the arm of the bell
crank H¹ is pulled violently upward, bringing the points of the fingers E in contact.
with the slides I'. The further movement of the car downward, owing to their
angles, forces them deeply into the said slides I', and the keys or wedges C, C,
resting upon them, are forced upward between the slides I¹ and 'the walls of the
recesses or notches in the ends of the safety plank or timber 12, locking said safety
plank or timber firmly to the slides.
If the suspensary is broken the cross bar L' and the bell crank H¹ are released,
and acting on the wedges or keys also lock the safety plank or timber I², both
wedges or keys being forced up simultaneously by the action of either bell-crank
lever...
This
My improved packing is composed of a leather cup O, which is attached to the
piston head T in the usual way, and held in position by a follower T¹. The said
leather cup has a flange projecting outward at the top, and its vertical part is
sufficiently long to allow a wearing surface of different material being placed imme-
diately under the flange and around the vertical part of the leather cup.
wearing surface O¹ may be of metal or any other suitable material. The leather
cup serves simply to prevent any leakage through the joints of the wearing surface,
and as it is not subjected to any wear itself, is very durable. The wearing surface
may be readily replaced whenever desirable by removing the follower T in the
usual way, as well understood by all skilled mechanics, and replaced at a very low
cost.
My improved shackle, clevis, or fastening consists of an open-ended loop or fork
g, which is made of brass or any suitable metal. or material, into which the rope or
cable is introduced after being doubled, and the ends of which are confined or.

page_text: embraced by a strap or band i to prevent their spreading. Preferably the rope is
passed around a center piece, drawn through the strap or band and out of the fork
or loop. Preferably also the outside of said centre piece n and the inside of said
loop or fork are made concave in order to hold the rope and keep it in its proper
position.
"
k
For attaching my shackel or clevis to the car I form an eye g' preferably in the
same piece with the fork or loop g, and which is arranged in line with the draft
rope or cable so that the pull is exerted in a direct line.
Having thus described the construction and operation of my improvements, what
I claim as my Invention and desire to secure by Letters Patent is,―
1st. In a hydraulic elevator the combination of two or more cylinders arranged
as desired, a corresponding number of piston heads (one in each cylinder) on a
common stem, a valve-governed conduit connecting the adjacent ends of the two
cylinders, a water supply port and a water discharge port to each cylinder, and a
valve in one of such water supply ports, substantially as and for the purpose
specified.
2nd. In a double cylinder and double piston hydraulic elevator, a valve-governed
water passage connecting the adjacent ends of the cylinders and a valve-governed
water supply to each cylinder, combined substantially as described with reference
to the automatic opening and closing of the valve between the cylinders, accordingly
as the water supply may be closed or opened.
3rd. In a double cylinder and double piston hydraulic elevator, in which one
piston is continuously subjected to water pressure, the combination of a pipe or
conduit P2 for transmitting such pressure, a valve-governed conduit from or con-
necting with the same source of pressure leading to the same side of the other
piston, and a valve device for bringing the discharge ports of both cylinders into
communication with the pressure pipe or conduits substantially as set forth.
4th. In a hydraulic elevator the combination of two or more cylinders arranged
as desired, a corresponding number of piston heads (one in each cylinder) on a
common stem, an arrangement of water supply ports for supplying water simulta-
neously to and exhausting it from the same side of the piston heads, such ports
being opened and closed for supply and escape by successive movements of a series
of valves on a single stem, substantially as set forth.
5th. In combination with two cylinders and two pistons (one in each cylinder)
on a common stem, a valve-governed circulation pipe P¹, arranged in one adjustment
of the valves to connect the main water supply with one end of its cylinder, and in
another adjustment to bring the opposite end of its cylinder into communication,
substantially as set forth.
6th. The pipes P1, P2, leading from the upper ends of the water chambers a, a¹,
through a common valve case, in combination with pipes or passages P, q, which
lead to the opposite ends of the same cylinders, substantially as set forth.
7th. The combination with an elevator platform, car, or cab of a safety plank or
timber whereon the platform, car, or cab rests, provided with notches or jaws
embracing slides and carrying wedges or keys, substantially as and for the purpose
specified.
8th. The combination with the safety plank or timber 12, provided with recesses
or notches and keys or wedges C, C, of the finger shaft and fingers E, E¹, bell-
crank levers H, H³, cross rod J, side rods K, K, M, M', and cross bars L, L¹, sub-
stantially as and for the purpose specified.
9th. In a piston the combination with a cup packing of a changeable wearing
surface, substantially as and for the purpose specified.
10th. In a piston the combination with the head T, cup O, having a changeable
wearing surface of any suitable material applied to its outer circumference, and the
follower T¹, substantially as herein shown and described.
11th. In a shackel, clevis, or fastening for a rope or cable, the combination of a

page_text: loop or fork, a strap or band for encompassing the ends thereof, and a center piece
around which the rope passes, substantially, as herein shown and described:
In witness whereof, I; the 'said Cyrus Baldwin, have hereunto set my
hand and seal, this Seventeenth day of July, in the year of our Lord One
thousand eight hundred and seventy-eight.
CYRUS RALDWIN (1.S.)
CYRUS BALDWIN (L.S.)