Improvements in the Method of, and Mechanisn for Working Hydraulic Elevators.
Year: 1896

page_text: COMPLETE. SPECIFICATION.
Improvements in the Method of, and Mechanisn for Working
Hydraulic Elevators.
I, NICHOLAS PENTREATH ROBERTS, of 102 Cecil Street, South Melbourne, in
the Colony of Victoria, Australia Hydraulic Engineer, do hereby declare the
nature of this invention, and the manner in which the same is to be used to be
particularly described and ascertained in and by the following statement :-
The object of this invention is to enable power to be economised in hydraulic
lifts where the loads vary at different times. Such economy is particularly
desirable when high pressure is employed say of 700 lb. or more to the square
inch.
To carry out my invention apply power.or pressure water in a particular
manner according to the nature of the load and to this end I provide mechanism
which includes two or more main cylinders, an, accumulator connected with the
same, an improved valve controlling the admission of power water to, and the
transmission of said water from, different parts of the mechanism, lever devices for
operating the valve and also for controlling the opening and closing of certain
passages, and other details as hereafter set: forth some of which are common to
hydraulic lifting mechanism.
In the accompanying drawings, mechanism, as employed in working my invention
is illustrated, such mechanism having two main cylinders, and like reference numbers.
indicating like parts in all the figures.
Figure 1 represents a side elevation partly in vertical section on, line, E E
in Figure 2 and Figures 9 to 11.
Figure 2 is an end elevation. partly in vertical section on the line A A
in Figure 1.
Figure 3 is a perspective view of the upper portion of the main slide valve
showing the recesses in its face.
Figure 4 is a section of the part in Figure 3 taken on the line F in Figure 1.
Figure 5 is a perspective view of the lower portion of the main slide valve
showing the recess in its face.
Figure 6 is a section of the part in Figure 5 taken on line G in Figure 1.
Figure 7 represents a detail of the wedge hereafter described.
Figure 8 is a diagrammatic elevation showing elevator apparatus.containing my
mechanism.
Figure 9 is a cross section on line B, B in Figures 1 and 7.
Figure 10 is a cross-section. on line C, Cin Figure 1.
Figure 11 is a plan on line D; Diin. Figure 1.
.
The manner of using my lifting mechanism will vary according as the load lifted
is light, or medium, or heavy, as also the load lowered.
In lifting a light load the minor main cylinder only would be in active use. This
I shall call case 1.
In lifting a medium load.too heavy for the minor main cylinder, the major main
cylinder only would be. in active use. (Case 2.)
In lifting a heavy load too heavy for the major main cylinder, both the major
and minor main cylinders would be in active use. (Case 3.)
In lowering a load of the heaviest class, the major main cylinder will exhaust-into
the accumulator. (Case 4.)
In lowering a medium load the minor, main cylinder will exhaust, into the
accumulator. (Case 5.)

page_text: In lowering a light load the accumulator is not being charged, but merely the
ordinary tank. (Case 6.)
In lifting, in cases 1 to 3, the accumulator power stores by cases 4 and 5 will be
utilized, and thus I secure economy.
The main cylinders I use have rams of progressively increasing effective area
such as 40 and 60 per cent. respectively of the whole ram head surface to which
pressure is applied and the expressions the "40" and "60" per cent. cylinders will
be used in describing such cylinders in this specification. The corresponding rams
may also be called in this description the 40 and 60 per cent. rams, although in
practice the two rams form one solid piece 29, shown in Figure 8.
30 and 31 represent the ram heads or effective areas open to pressure in the main
cylinders 18 and 32, it being understood that the effective area or head 31 is
annular.
In the drawings 10, 43, 59 and 42 (vide Figure 2) are respective passages or
ports in the central body of the apparatus, said ports ending on the seating or
surface within the valve box, on which the face of valve 11 slides. The passages 10
and 42 are in communication through tubes 12 and 56 respectively, with plunger
cylinders 13 and 15 respectively, vide Figure 9; and the passage 43 leads to a
chamber 53 having valve 52 therein said chamber communicating by passage 54
with the main exhaust passage 40, vide Figure 1. The passage 59 communicates
direct with the main exhaust passage 40. Passage 40 is open at one end to control
by valve 11, the other end leading to parts more particularly shown in Figure 10
and hereafter described.
The main pressure inlet port controlled by valve 11 is at one end of
passage 27, (Figure 1) which leads to a central chamber 19 having two
outlets viz. channels 16 and 66 which are on opposite sides of the said chamber
(vide Figure 9). The channels 16 and 66 communicate (through valve cylinders 15
and 13 respectively) with tubes 17 and 34 respectively, tube 17 leading to
the 40 per cent. main cylinder 18, and tube 34 leading by pipe 33 into the 60 per cent.
main cylinder 32 as seen in Figure 8.
It will thus be seen that power water entering 27 can pass to the main cylinders.
The emptying of the 40 per cent. cylinder 18 is effected (vide Figures 8, 9, and 1)
through pipe 17 leading to chamber 19 and passage 27, thence through recess 41
in the lower part of valve 11, into main exhaust passage 40 to pipe 38 (vide Figure 10)
leading to tank 39. The tube 17 is also in cominunication with a chamber 60
which is closed, or opened on one side by the valve 61 between said chamber and
pipe 62 which leads to accumulator 63; and as will be seen hereafter the return
water from 18 frequently goes to the accumulator.
The return water from cylinder 32 passes through tube 33, into tube 34 thence
either to chamber 19 and by way of parts 27, 41, 40 and 38 to 39; or by way of
chamber 35, with which tube 34 communicates, past valve 37 into tube 62 and
thence to accumulator 63.
The charging of this accumulator takes place whenever the pressure of the return
water from 18 or 32 is sufficient to lift valve 61 or 37 respectively, and is therefore
dependent on the load the accumulator carries, which in practice I usually make
higher than the pressure of the main. 36 and 77 are valves to chambers 35 and 60
respectively and their use is explained below. Within the cylinders 15 and 13
respectively, are the plungers 9 and 8, which project through the open bases of the
cylinders and rest upon the ends of a centrally pivoted lever 14, so that as either
plunger descends and moves its end of the said lever, the other plunger will be
simultaneously raised by the other end of the lever..
On referring further to Figure 9 it will be seen that the cylinders 15 and 13
have each an enlarged interior space to allow of the water passing round plungers 9
and 8 respectively when issuing through channels 16 and 66 respectively, and that
the plungers are fitted with blocks 57 (whichl usually make of lignum vitæ), lor
the closing of the passages 16 and 66 at certain times. Sometimes passage 66 is
open and 16 closed, and vice versu, and at other times both are open.

page_text: The face of valve 11 has (or the faces have, the valve being preferably in two
parts) as shown in Figures 1, 3 and 5 the following parts viz., recess 41 previously
mentioned which is to put passages 27 and 40 into communication; recess 44 which
puts passages 10 and 43 into communication; recess 58 which puts 42 and 59 into
communication; recess 65 which answers the same purpose as recess 44 when
the valve is in the upper position; recesses 74 and 75 one or the other of which at
certain times allows the pressure water entering the valve box at 28 to pass through
passage 42 and thence as already set forth; and recess 76 to allow pressure water
entering at 28 to pass through passage 10 at certain times.
In working this invention the usual hand rope or chain which is connected to
one end of the valve lever will he actuated by the operator. This valve lever,
marked 20 is pivoted at 21, and carries connecting strap 22 lever 23 pivoted at 24
with strap 25 connected to the valve spindle 26. This compound leverage allows
of a gradual delicate adjustment of the valve 11. The lever 20 is provided with
projections 45, 64, and 68, of which 45 and 64 are each adapted to strike projec-
tion 46, on weighted lever 47 pivoted at 49, (the weight being shown at 48) at
certain times; 68 being adapted at certain times to strike projections 69 on the
sliding block 70. When projection 46 is depressed it lowers the strap 50 connecting
lever 47 to spindle 51, so that the valve 52 is operated.
55 is an adjusting screw for regulating the area of the passage 54.
When the projection 68 is not directly opposite projection 69 the part 70 is free
to slide towards lever 20, and at certain times it does so, that is when the wedge 73
is pushed in the direction of the arrow in Figure 7, thereby sliding along bolt 72
and moving the pivoted lever 71 to which the part 70 is connected. 67 shows
framing.
When the lift is at rest valve 11 is in its middle position as in Figure 1, and,
port 10 being open to the pressure water, plunger 8 is depressed and plunger 9
raised, and passage 16 open leaving free communication between passage 27 and
main cylinder 18.1
In describing the method of working my invention it will be convenient to
explain the several cases aforesaid successively.
In case 1. wz., the raising of a light load, valve 11 is raised till 27 is open to the
pressure, which then passes through 19, 16, 17 and into the 40 per cent. cylinder 18
depressing 30, the minor effective head of ram 29. This depression causes the
annular space above the major effective area 31 within the 60 per cent. cylinder 32
to enlarge, tending to cause a vacuum, which is prevented by water filling the space
from pipe 33 connecting with pipe 34, chamber 35 (having valve 36), tube 38, and
tank 39, the suction enusing valve 36 to open whenever necessary.
In case 2, the liftman raises valve 11 higher than in the former case so that not
only is 27 opened to the pressure, but passage 42 also becomes opened to it, and
projection 64 on lever 20 at the same time strikes and depresses the part 46,
opening valve 5%. The consequence is that the pressure water entering 42 goes
through tube 56 and depresses plunger 9 until the passage 16 is closed by blocks 57,
and 66 is opened by the position plunger 8 assumes.
Water from above plunger 8 is forced out of the cylinder through pipe 12,
recess 65, port 43, chamber 53, passage 54 into main exhaust pipe 40; and it will
be seen that it is when recess 75 is above passage 42 that recess 65 is above the
two passages 10 and 43.
The pressure water enters at 27 then goes through 66 into 34, then to 33 and
then 32, pressing upon the 60 per cent. ram head 31. In this case the space above
ram head 30 becomes filled with water from the series of connections 17, 60,
(having valve 77), 38, and 39. The valve 52 is allowed to close which it does
automatically when the operator releases the hand rope the weight 48 on lever 47
and the pressure of the water on the valve 52 causing 64 to recede sufficiently to
allow 46 to rise. The passage 4 being sufficiently narrowed by screw 55, the
pressure will be found sufficient to close valve 52 at the state indicated.
In the 3rd case viz. of raising the heaviest class of loads which can be taken the

page_text: valve 11 is raised as high as in case 2 and maintained so, in which case the water
coming through 56, causes plunger 9 to assume its lowest position and plunger 8
its highest, so that chamber 19 is in communication with both 34 and 17 by the
open passages 16 and 66, the water which enters at 27 thus passing to both the
ram heads simultaneously."
In stopping the lift after working either as per case 2, or as per case 3, (and in
every case from 1 to 6 the stopping is caused by bringing valve 11 to the middle
position as Figure 1), as a very quick stop and a fresh start might not leave port 10
open long enough to allow the plungers 8 and 9 to resume the initial position
shown in Figure 9 before the new start is made, the wedge arrangement shown in
Figures 1,7, and 9 is generally used since the change cannot then be effected till 68 bas
pushed back the end 69 and thus shifted 73 till it is under 14 as shown in Figure 7,
in other words till plunger 8 is depressed. During the operation of case 2 or case 3
the end 69 takes the position shown in dotted lines in Figure 1 because plunger 9
in descending pushes back wedge 73. This wedge arrangement therefore restores
the initial position of the pistons allowing the next ascent to be made as per either
case 1, 2, or 3 as may be proper.
In case to better utilize the power of the water leaving cylinder 32 when the
life is descending with a sufficiently heavy load, the valve 11 is lowered till there
is communication between passage 27 and 40 through recess 41, but lever 20
nctuating valve 11 is not moved so much as to cause depression of valve 52. Ia
this case as the plungers 8, 9 assume the position in Figure 9 when the lift begins
to descend, the passage of water from 32 is to 33, 34 and (as 66 is closed)
through 35 past valve 37 into 62 and thence into 63.
On referring to the explanation given below of case 6.it will be understood how
in this case the waste water from 18 exhausts into 39.
In case in wbich there is reciprocation of power from the 40 per cent.
cylinder 18 into the accumulator as the lift descends the valve 1! is depressed to
its lowest position so that projection 43 strikes and lowers 46 and opens the
vulve 52. When 52 is open, the pressure through 42 and 56 causing the plunger 9
to descend and 8 to ascend, the water from 13 passing out through 10, 43, 53, 54,
and so on, until passage 66 is opened and 16 closed, whereupon the water passes
from 18 to 17, to 60, past 61 into 62 and 63, allowing the lift to descend, during
which descent the plungers 8 and 9 will retain the positions last named. The
valve 52 will have closed automatically when on the descent beginning the hand
rope was released.
In case 6 viz. to descend without using the accumulator, valve 11 is lowered so
that there is communication between passages 27 and 40 through recess 41, the
water from the supply being then open to port 42 only, and communicatiou
existing between 10 and 43 through recess 44 in the valve. In thus lowering
the valve the projection 45 on lever 20 is made to strike projection 46 causing
valve 62 to open. The water pressure through 42 passes through pipe 56 into
cylinder 15, depresses plunger 9 to its lowest position, and (by the agency of
lever 14) raises plunger 8, forcing out the water from 13. into 40 through the
course already detailed.
The weight of, or load on, the lift will then raise the ram 29 and force the water
from 18 through 17 and 16 into exhaust pipe 40 then to 38 and tank 39.
The water from 32 is forced through 33 into 34 to 66, into exhaust chamber 40,
then to 38 and tank 39.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. The method of working hydraulic elevators, having a major and a minor main
cylinder and passages (controlled by plungers which are operated by the power
water) leading thereto (for the transmission of power, water), which consists in
causing the plunger controlling the passage to the minor main cylinder to open

page_text: said passage, and the passage for the transmission of power water to the major
main cylinder to be closed by the plunger controlling the latter, substantially as.
hereinbefore set forth with reference to case 1.
2. The method of working hydraulic elevators, having a major and a minor main
cylinder and passages (controlled by plungers which are operated by the power
water) leading thereto (for the transmission of power water), which consists in
causing the plunger controlling the passage to the major main cylinder to open
Baid passage, and the passage for the transmission of pewer water to the minor
main cylinder to be closed by the plunger controlling the latter, substantially as
hereinbefore set forth with reference to case 2.
3. The method of working hydraulic elevators, having a major and a minor main
cylinder and passages (controlled by plungers which are operated by the power
water) leading thereto (for the transmission of power water), which consists in
causing the plungers controlling the passages to the cylinders to leave said passages
simultaneously open substantially as hereinbefore set forth with reference to case 3
aforesaid.
4. The method of working hydraulic elevators, having a major and a minor main
cylinder and tubes therefrom leading to passages (controlled by plungers operated
by the power water) and to passages controlled by valves operated by the exhaust
water, which consists in exhausting, water from the major main cylinder into an
accumulator without exhausting water from the minor main cylinder thereinto
substantially as herein before set forth with reference to case 4 aforesaid.
5. The niethed of working hydraulic elevators, having a major and a minor main
cylinder and tubes therefrom leading to passages (controlled by plungers operated
by the power water) and to passages controlled by valves operated by the exhaust
water, which consists in exhausting water from the minor main cylinder into an
accumulator without exhausting water from the major main cylinder thereinto,.
substantially as hereinbefore set forth with reference to case 5 aforesaid.
6. The method of working hydraulic elevators, having a major and a minor main
cylinder and tubes therefrom leading to passages (controlled by plungers operated
by the power water) and to passages controlled by valves operated by the exhaust
water, which consists in exhausting water from both the major and minor main
cylinders concurrently through both passages controlled by the said plungers
without exhausting water into the accumulator from either cylinder, substantially
as hereinbefore set forth with reference to case 6 aforesaid.
7. In hydraulic elevator mechanism, the arrangement and combination of the parts
herein before described with reference to Figure 2 of the accompanying drawings.
8. In hydraulic elevator mechanism, the arrangement and combination of the
parts hereinbefore described with reference to Figures 3 and 4 of the accom-..
panying drawings.
9. In hydraulic elevator mechanism, the arrangement and combination of the
parts hereinbefore described with reference to Figure 7 of the accompanying.
drawings.
10. In hydraulic elevator mechanism, the arrangement and combination of the
parts hereinbefore described with reference to Figure 9 of the accompanying
drawings.
11. In hydraulic elevator mechanism, the arrangement and combination of the
parts hereinbefore described with reference to Figure 10 of the accompanying.
drawings.
12. In hydraulic elevator mechanism, the arrangement and combination of the
parts hereinbefore described with reference to Figure 1 of the accompanying.
drawings.
13. In hydraulic elevator mechanism, a valve box to which power water is
admitted and having a valve 11, therein, passages 10 and 42 communicating
respectively by tubes 12 and 56 with cylinders 13 and 15 having plungers 8 and 9
therein, and a lever 14 contacting with both plungers, all in combination sub-
stantially as set forth.

page_text: 14. In hydraulic elevator mechanism, the combination of cylinders 13, 15,
plungers 8, 9, chamber 19, and passages 16, an.1 66 substantially as, and for the
purposes set forth.
15. In hydraulic elevator mechanism, the combination of a valve box, into which
the pressure water is admitted passages 10, 42 and 43 opening thereinto recess 44
(in a valve, 11) connecting passages 10 and 43 and recess 74 simultaneously
opening passage 42 to the pressure water substantially as and for the purposes set
forth.
16., In hydraulic elevator mechanism, the combination of a valve box into which
the pressure water is admitted passages 10, 42, and 59 opening thereinto, recess 58
(in a valve 11) connecting passages 42 and 59, and recess 76 simultaneously
opening passage 10 to the pressure water substantially as and for the purposes set
forth.
17. In hydraulic elevator mechanism, the combination of a valve box into which
the pressure water is admitted passages 10, 42 and 43 opening thereinto, recess 65
(in a valve 11) connecting passages 10 and 43 and recess 75 simultaneously
opening passage 42, to the pressure water substantially as and for the purposes set
forth.
18. In hydraulic elevator mechanism, the combination of a valve box, a slide
valve having recesses, 41, 44, 58, 65, 74, 75, and 76 in its face, and a seat on which
the valve rests having the ends of passages 27, 40, 10, 43, 59, and 42 opening to
the valve face substantially as and for the purposes hereinbefore set forth.
19. In hydraulic elevator mechanism, a major main cylinder having ram 29 with
effective area 31 and connecting pipes 33, 34, in communication with a chamber 35,
and also in communication with the end of a passage 66 substantially as and for
the purposes set forth.
20. In hydraulic elevator mechanism, a minor main cylinder 18 having a ram 29
with effective area 30 and connecting piping 17 in communication with a chamber 60
and also in communication with the end of a passage 16 substantially as and for
the purposes set forth.
21. In hydraulic elevator mechanism, a chamber 19 communicating by respective
passages with a major, and with a minor main cylinder and with two chambers 35
and 60 having valves 37 and 61 adapted to be opened by internal pressure to allow
either or both of said main cylinders to exhaust into an accumulator substantially
as and for the purposes set forth.
22. In hydraulic elevator mechanism, a chamber (35 or 60) having a valve (37
or 61) openable only by internal pressure, and allowing communication with an
accumulator, and also a valve (36 or 77) openable only by external pressure and
allowing, communication from a tank, substantially as aud for the purposes set
forth.
23. In hydraulic elevator mechanism, a compound lever having parts 20 to 25,
45 and 64 substantially as and. for the purposes set forth.
24. In hydraulic elevator mechanism, the combination of a valve 52 and
connected parts 46 to 51 substantially as and for the purposes set forth.
25. In hydraulic elevator. mechanism, the combination with exhaust passage 40
of passage 54, chamber 53, valve 52 and passage 43 substantially as and for the
purposes set forth.
26. In hydraulic elevator mechanism, the wedge 73 and connected parts 69
to 72, in combination with lever 14 and projection 68 substantially as and for the
purposes set forth.
Dated this 28th day of July 1896.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.