Year: 1899

page_text: Date of Application, 21st June, 1899
L
0014
4000
Assentrd
40th Au
1000
We, FRED GRANTHAM BROUGHTON and ERNEST CHRISTOPHER BROUGHTON, both
of 29, Laurel Grove, Anerley, in the County of Surrey, Engineers, do hereby
declare the nature of this invention to be as follows:-
This invention relates to improvements in and connected with sack lifters.
In sack lifters as hitherto usually made, that is to say, in sack lifters wherein
a platform for holding the sack is held upon a suitable support, such as a sack
barrow, and is adapted to be raised by means of a crank and axle and chains,
the platform and the chains are frequently broken owing to the sudden fall of the
platform when the ratchet gear in connection with the crank and axle is released
to allow of the said platform being lowered. Such machines are usually pro-
vided with a suitable hand-brake, for example a band-brake, to control the
descent of the platform, but these brakes have been found to be unsatisfactory.
in practice.
Now, it is the object of our invention to provide simple and efficient means, for
controlling the descent of the platform after a sack has been removed therefrom
and to this end we employ in conjunction with the said rising and falling plat-
form a cylinder and piston designed, when the platform is raised, to draw a
charge of air into the cylinder, which said charge of air on the descent of the
platform acts as a buffer and controls the descent of the said platform.
In carrying out the invention we advantageously connect the cylinder to the
support for the platform and the piston to the said platform, a suitable back pres-
sure valve being provided in the lower end of the cylinder to allow the air to
enter when the platform is raised and normally to prevent its escape. Suitable
means can also be provided for opening the said valve when it is desired to allow
the platform to descend. Furthermore, the bottom of the cylinder is, provided
with a kind of well for containing a liquid, such as oil or water, into which the
piston plunges on its descent. The object of this liquid well is to lubricate the
working parts of the apparatus thereby preventing the wear thereof and at the
same time to act as an additional safety buffer should the air buffer, for any
reason, fail to act.
.
Our invention is especially applicable to what are known as combined sack
holders, lifters and weighing machines as used by farmers, millers, corn
merchants, coal merchants, warehousemen, etc.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.

page_text: Improvements in and connected with Sack Lifters.
3
We, FRED GRANTHAM BROUGHTON and ERNEST CHRISTOPHER BROUGHTON, both
of 29, Laurel Grove, Anerley, in the County of Surrey, Engineers, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention relates to improvements in and connected with sack lifters.
In sack lifters as hitherto usually made, that is to say, in sack lifters wherein
a platform for holding the sack is held upon a suitable support, such as a sack
barrow, and is adapted to be raised by means of a crank and axle and chains,
the machine is frequently broken owing to the sudden fall of the platform when
the ratchet gear in connection with the crank and axle is released to allow of
the said platform being lowered. Such machines are usually provided with a
suitable hand-brake, for example a band-brake to control the descent of the
platform, but these brakes have been found to be unsatisfactory in practice.
Now, it is the object of our invention to provide simple and efficient means for
controlling the descent of the platform after a sack has been removed therefrom
and to this end we employ in conjunction with the said rising and falling plat-
form one or more cylinders and pistons designed, when the platform is raised,
to draw a charge of air into each cylinder, which said air on the descent of the
platform acts as a buffer so as to control the descent.
In carrying out the invention we advantageously connect the cylinders to the
support for the platform and the pistons to the said platform, a suitable back
pressure valve being provided in the lower end of each cylinder to allow the air
to enter when the platform is raised and normally to prevent its escape.
Suitable means can also be provided for opening the said valve when it is
desired to allow the platform to descend. Furthermore, the bottom of the
cylinder is provided with a kind of well for containing a liquid, such as oil or
water, into which the piston plunges on its descent. The object of this liquid
well is to lubricate the working parts of the apparatus thereby preventing the
wear thereof and at the same time to act as an additional safety buffer should
the air buffer, for any reason, fail to act.
Our invention is especially applicable to what are known as combined sack
holders, lifters and weighing machines as used by farmers, millers, corn
merchants, coal merchants, warehousemen, etc.
In the accompanying drawings,-
Figure 1 is a front sectional elevation of a hand-barrow sack lifter having our
improvements applied thereto :
Figure 2 is a sectional plan, the section being taken on the line 2-2 Figure 1:
Figure 3 is a sectional side elevation of the machine:
Figure 4 is a vertical section through one of the cylinders, drawn to a larger
scale:
Figure 5 is a transverse section on the line 5-5 Figure 4:
Figure 6 is a section on the line 6-6 Figure 4; and
Figure 7 is a sectional elevation illustrating a modified construction of the
machine.
The machine shewn is of the kind described in the Specification of British
Patent No. 1392 of 1883. a, a are the side frames of the sack lifter, the said side
frames being connected together by cross-bars a¹ and being provided with a
foot a upon which are mounted wheels a³. is the weighing platform or

page_text: elevator, the said elevator having side-bars 61 which slide in grooves at in the
side frames a, a. cc are the hoisting chains which are connected at one end to
the frame carrying the platform b and at the other end to the windlass or
barrel e adapted to be rotated by the gear and handle 3; is the ratchet and
pawl gear which normally prevents the descent of the platform b.. All these
parts are of well known construction and we make no claim to them in this
specification.
d, d are the cylinders which are fitted to the side frames a, a and which are
provided with pistons e. having rods el which pass through the upper cylinder
covers and are connected with the side-bars through the medium of connect-
ing rods attached to cross pieces 2 connecting the side bars 61, as clearly
indicated in the drawings, Each cylinder is provided with a hole d² in the
lower cylinder cover the said hole being normally closed by a valve preferably
of, the kind shewn, that is to say, of a curved strip of spring metal d which
is secured at one end to the cylinder cover 3 the free end being held by the
elasticity of the strip, against the hole da so that air is allowed to enter the
cylinder on the upward movement of its piston e but is prevented from escaping"
therefrom on the downward stroke of the piston.
d, d are the wells formed at the lower ends of the cylinders for holding
the oil; water or other liquid into which the pistons e plunge, as shewn in
Figure 4, in their descent thereby lubricating the working parts of the apparatus
and acting as an additional buffer.
e2 is a spring piston valve (preferably of the kind above described) which
closes a small hole e³ passing through the piston and allowing the spaces on the
two sides of the piston to communicate with one another and e* are holes made
in the top end of the cylinder.
With this arrangement when the platform b is elevated in the usual manner
by means of the hoisting gear 2, 3 the pistons e are raised in the cylinders d
so as to draw into each cylinder a charge of air through its hole d³. When the
platform has been raised to its uppermost position it is held by the ratchet and
pawl gear and when the sack which it contains has been weighed in the usual
manner the said gear c is released so as to allow the platform to descend. The
descent is, however, controlled by the air in the cylinders which acts as a buffer
hindering the descent which can only take place gradually as the air escapes
through the piston valves c so that the very frequent breakages of, or damage to,
the platforms or other parts of sack lifting machines is obviated.
In the modified arrangement illustrated in Figure 7 the connecting rods f
are not rigidly connected to the piston rods e¹ as is the case in the first described
arrangement but each rod f is provided with a hole fi through which the piston
rod e' passes so that the rod f can slide upon the piston rod which is lengthened
so as to project to a considerable extent beyond the cylinder. Each piston rod
is also provided with two collars g, g between which the rod f can slide so that
when the platform b is elevated or lowered in the usual way it does not operate
the pistons for a portion of its stroke, that is to say, whilst the rods f, f are
sliding upon the piston rods e¹ between the two collars g, g. By this means we
are enabled to considerably reduce the length of the cylinders d.
Although we have described and illustrated our improvements in connection.
with a combined sack lifter and weighing machine it will be obvious that they
can be also applied to any sack lifter or like machine which has a platform
arranged to rise and fall. It will also be obvious that the inlet and outlet of the
air can be controlled by any suitable means other than those above described.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. In a sack lifter, the combination with the platform or elevator of a pneu-
i

page_text: matic cushion or buffer for preventing the sudden descent of the said platform,
substantially as hereinbefore described.
2. In a sack lifter the combination with the platform or elevator of one or
more cylinders each having a piston so that air is introduced into the cylinder
or cylinders under the piston or pistons when the platform is raised and allowed
to gradually escape when the platform is required to descend, substantially as
herein before described.
3. In a sack lifter, the combination with the platform or elevator of one or
more cylinders having pistons, both cylinders and pistons having valves so
arranged that when the platform is raised air is introduced into each cylinder
and is allowed to escape gradually on the descent of the platform, substantially
as herein before described.
4. In a sack lifter the combination with the platform or elevator of one or
more cylinders having liquid wells at their lower ends, pistons adapted to plunge
into the wells on this downward stroke and valves so arranged that when the
platform is raised air is introduced into the cylinders, the said air being allowed
to escape gradually on the descent of the platform substantially as, and for the
purpose, herein before described.
5. In a sack lifter, the combination with the platform or elevator of one or
more cylinders secured to the frame of the sack lifter of pistons working in the
cylinders and having rods secured to the movable platform, and of means for
admitting air into the cylinders when the platform is raised and for gradually
allowing the air to escape when the platform is to descend, substantially as herein-
before described.
6. In a sack lifter, the combination with the platform or elevator of one or
more cylinders secured to the frame of the sack lifter of a piston or pistons
working in the said cylinder or cylinders and each having a rod projecting
beyond the cylinder, of collars upon each projecting piston rod and of connect-
ing rods adapted to slide upon the piston rods between the collars and connected
to the platform or elevator, substantially as herein before described.
7. The improved sack lifters hereinbefore described and illustrated in the
accompanying drawings.
Dated the 28th day of June 1899.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.