Improvements connected with Hydraulic Lifts.
Year: 1895

page_text: Date of Application, 21st May, 1895
Complete Specification Left, 21st Mar., 1896-Accepted, 9th May, 1898
PROVISIONAL SPECIFICATION.
Improvements connected with Hydraulic Lifts.
I, AXEL BREMBERG, of 32 Victoria Street, Westminster, Engineer, do
hereby declare the nature of this invention to be as follows:-
:-
This invention relates to improvements connected with hydraulic lifts.
According to my invention I provide hydraulic lifts with an automatic safety
appliance or device which is arranged in such a manner that so long as the lift is
working under normal conditions the said appliance or device remains inactive, but
in the event of the pressure within the system for any reason becoming abnormally
and accidentally reduced the said appliance or device immediately comes into
operation and by creating friction on the lift ram retards or stops the descent
thereof. In this way the injury that might otherwise occur to passengers owing to
the falling of the lift is avoided..
For the purpose of my invention I provide a divided band or collar which
embraces the lift ram at some point in proximity to the ram-cylinder. This band
or collar is provided with lugs having transverse holes for the reception of a pin or
stud projecting laterally from one end of a lever, said pin or stud serving as the
fulcrum of the lever. One of the holes in the said lugs is screw-threaded and a
portion of the aforesaid pin or stud is likewise screw-threaded to engage therewith.
Situated in contiguity to the lift ram-cylinder is a subsidiary ram working in a
cylinder that is in free communication with the said lift ram-cylinder. The
subsidiary ram is so arranged that its upper end comes immediately beneath the
free end of the before mentioned lever. This lever is furnished with transverse
projections acted upon by spiral springs that tend to keep the free end of said
lever constantly pressed upon the upper end of the subsidiary ram. When the lift
is in its normal condition, the pressure within the subsidiary cylinder causes its
ram together with the free end of the said lever to be forced upwards, whereby the
collar is opened and the springs are extended until the pressure on the lower end
of the subsidiary ram is counter-balanced by the springs. Should however an
abnormal reduction of pressure take place in the subsidiary ram-cylinder owing to
a fracture of any of the pipes of the system or owing to any other cause, the
aforesaid pressures no longer counterbalance one another and the springs overcome
the upward pressure of the subsidiary ram, thereby forcing the outer end of the
lever downwards. This movement causes the fulcrum pin or stud to turn in the
screwed lug of the divided band or collar and to bring a shoulder on said pin or
stud against the other lug of the collar thereby forcing these lugs together and
causing the collar to grasp the lift ram with sufficient force to prevent its rapid
descent.
Instead of the divided band or collar above mentioned, I may employ any other
friction device that may be found equally suitable for the purpose.
The aforesaid springs may be provided with slotted bars or links which can be
so arranged that the extension of the said springs, under the action of the
subsidiary ram, can be limited.
Dated this 21st day of Mov 1805

page_text: COMPLETE SPECIFICATION.
Improvements connected with Hydraulic Lifts.
I, AXEL BREMBERG, of 52 Victoria Street, Westminster, Engineer, 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:-
This invention relates to improvements connected with hydraulic lifts.
According to my invention I provide hydraulic lifts with an automatic safety
appliance or device which is arranged in such a manner that so long as the lift is
working under normal conditions the said appliance or device remains inactive, but
in the event of the hydraulic pressure within the system for any reason becoming
abnormally reduced the said appliance or device immediately comes into operation
and by causing pressure to be exerted on the lift ram, acts as a brake to retard or
stop the descent thereof. In this way the injury that might otherwise occur to
passengers owing to the accidental falling of the lift is avoided.
I
For the purpose of my invention I provide the main or lift cylinder with a
subsidiary cylinder communicating therewith, and I arrange at some point in
proximity to the said lift cylinder a brake-band or friction-collar which embraces
the lift-ram and is furnished with means, such as a spring controlled or weighted
lever, for causing the brake-band to grip the lift-ram. This lever is normally kept
out of action by the ram of the aforesaid subsidiary cylinder, but in the event of a
fracture taking place in any of the pipes of the system, or for any other reason,
the pressure in the system suddenly falls abnormally low the aforesaid ram of the
subsidiary cylinder will allow the lever to act, thereby causing the brake-band or
friction-collar to grasp the ram with sufficient force to stop or retard the rapid
descent of the lift.
In order that my said invention may be clearly understood and readily carried
into effect I will proceed to describe the accompanying drawings in which:-
Figure 1 is a side elevation shewing my invention applied to an hydraulic lift,
the main cylinder of which is supported by a cross-beam or girder.
Figure 2 is a sectional elevation shewing my invention applied to a lift where
such a cross-beam or girder does not exist.
Figures 3 and 4 are respectively a horizontal section on the line 1. 1 of Figure 2
and a vertical section on the line 2.2 of Figure 3.
Figure 5 is a plan and Figure 6 a vertical section shewing a method of
conveniently affixing the brake-band or friction-collar to an ordinary lift-ram
without unduly interfering with existing parts of the lift.
A is the main cylinder and A' its ram; B is the subsidiary cylinder and B' its
ram; C is the lift.
D is the brake-band or friction-collar which in Figures 1 to 4 consists of a
divided ring having lugs d d thereon. These lugs are formed with holes for the
reception of a pin or stud e which pivotally connects the lever E to the said brake-
band. One of the holes in the said lugs is screw threaded and a portion of the,
aforesaid pin or stud e is likewise screw-threaded to engage with this hole, so that
when the lever E is depressed it turns the pin or stud e and causes the two lugs to
approach each other, thereby compelling the brake-band to grip the ram A'. The
outer end of the said lever is in Figure i connected to a spiral spring El and in
Figure 2 is provided with an adjustable weight E' so that the outer end of the
said lever has a constant tendency to turn downward into a position represented by
the dotted lines in Figure 2. This tendency is however overcome by the ram B¹
of the subsidiary cylinder B which as already stated is in communication with the
main cylinder A. Thus so long as the pressure within the main cylinder is normal,
the ram B¹ is kept in the elevated position shewn in the drawings and supports the
lever E.

page_text: In order to avoid the downward thrust which would otherwise come on the-
cylinder A in the event of the brake-band coming into operation, it will not be
practicable to allow the said brake-band to rest on the gland of the stuffing.
box A2, or to otherwise be supported by the cylinder A. I therefore provide a
yoke-piece F which in Figure 1 is adapted to be bolted to and supported by the
transverse beam or girder G, and in Figure 2 to be bolted to a ring H supported:
by uprights or standards H'. On this yoke-piece the said brake-band rests. To.
prevent the brake-band from turning around the ram A', I provide it with a short
pin or projection d' (Figure 4) which engages with a shallow slot or recess f¹ on-
the surface of the yoke-piece F. The said brake-band is also furnished with
lateral fins or projections d² d which come beneath lips ff on the yoke-piece;:
by these means the brake-band is restrained from shifting vertically with the
ram A' as the latter rises in working the lift. As a convenient method of enabling
the aforesaid yoke-piece to be removed and the stuffing box A2 to be reached,.
I provide the ring H (Figures 2, 3 and 4) with swivel bolts and form the yoke-
piece with slots h with which these bolts engage, when in their vertical position..
By turning these bolts outwardly the yoke-piece is at once released.
The ram B of the subsidiary cylinder B has a shoulder b (Figure 2) which.
limits the extent to which the said ram can rise and prevents it from entirely
leaving the cylinder B.
In order to ensure that the lever and its screw pin shall not become fixed by
inaction and fail to operate at the required moment, the lift C is provided with a.
spring controlled pusher c which comes against the lever E each time the lift
descends to its lowermost position and thereby slightly depresses the lever and
the ram B'.
61 is an air passage in the gland of the subsidiary cylinder B to ensure that air
shall have free access to the space above the shoulder b, so that when decrease of
pressure takes place in the cylinder, the ram B' will not be impeded from promptly
descending owing to a partial vacuum that might otherwise be formed in the space-
above the said shoulder.
Figures 5 and 6 shew a slightly modified construction of the brake-band and its
supporting yoke-piece. In this case each of the holes in the lugs d of the brake-
band D is screw threaded; the threads of one hole being right-handed and in the
other left-handed. The pin or stude on the lever E is also formed with right and
left handed screw-threaded portions for engagement with these holes. The brake-.
band D and the yoke-piece F are formed in two portions or halves, so that they
can be readily applied to the ram of a lift already erected without the necessity of
disturbing any of the existing parts of the lift. The halves of the brake-band are
first applied to the ram A' with the double threaded screw in place between the-
two lugs d d. This screw is then revolved, thereby causing the halves of the brake-
band to approach each other and embrace the said ram. The pivot pin d³ is next
inserted in place from beneath the brake-band. The halves of the yoke-piece are
then applied to the ram and in so doing the lower end of the pin d³ is brought into
engagement with the notch or recess f¹ and the fins are also brought into-
engagement with the lips 2. The halves of the yoke-piece are then bolted firmly
together by the bolts and finally the lever E is connected to the end of the said
pin e by a key or other suitable means.
Although I have described my safety appliance in connection with a lift, it will
be obvious that it can be equally well applied to the ram of an accumulator and
would act in an analogous manner to that above stated for preventing the sudden,
falling of the accumulator in the event of an abnormal decrease in pressure in the
hydraulic system taking place.
Having now particularly described and ascertained the nature of iny said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
auplian
for
1100
with
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hedraulic
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page_text: combination of a spring controlled or weighted lever acting in conjunction with a
brake-band which is supported independently of the lift cylinder and of a subsidiary
hydraulic cylinder which normally prevents the said lever from being influenced by
its spring or weight substantially as described.
2. The combination with the aforesaid brake-band of a support or yoke-piece
provided with a notch or recess f¹ and lips for the reception of corresponding
pieces on the brake-band, for the purposes specified.
3. My improvements connected with hydraulic lifts, substantially as described
with reference to the accompanying drawings and for the purpose specified.
Dated this 21st day of March 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.