Improvements in Machinery or Apparatus for Raising and Lowering Weights.
Year: 1890

page_text: Date of Application, 3rd Nov., 1890
Complete Specification Left, 17th Dec., 1890-Accepted,: 31st Jan., 1891
PROVISIONAL ST BUT FIGATION.
Improvements in Machinery or Apparatus for Raising and Lowering
Weights.
1, PETER MITCHELL, of Greatham Terrace, West Hartlepool, in the County
of Durham, Assistant Manager of Ship Yard and Graving Docks, do hereby
declare the nature of this invention to be as follows :-
:-
My invention relates to improved apparatus for raising and lowering heavy
bodies.
In carrying out my invention I provide a lifting chain, the links of which are
constructed with peculiarly shaped teeth, which chain is passed over a suitably
formed sheave or pulley carried in a suitable block, frame or stirrup. In connec-
tion with the frame is mounted a lever carrying a pawl or catch adapted to engage
with the teeth of the chain in such a manner that when the lever is, say, depressed
the weight will be raised. A catch is provided for holding the chain during the
time that the lever is being moved back ready for the next lift.
The apparatus hereinbefore described is of especial use for raising the plates for
ships' bottoms into position for rivetting and when so used I advantageously
suspend the hoisting apparatus from a kind of tripod having clips at the ends of
the legs by means of which the said tripod may be readily secured to the floor
beams of the ship.
Dated the 3rd day of November 1890
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements in Machinery or Apparatus for Raising and Lowering
Weights.
1, PETER MITCHELL, of Greatham Terrace, West Hartlepool, in the County
of Durham, Assistant Manager of Ship Yard and Graving Docks, do hereby
déclare 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 improved apparatus for raising and lowering heavy
bodies.
In carrying out my invention I provide a lifting chain, the links of which are
constructed with peculiarly shaped teeth, which chain is passed over a suitably
formed sheave or pulley carried in a suitable block, frame or stirrup. In connec-
tion with the frame is mounted a lever carrying a pawl or catch adapted to engage
with the teeth of the chain in such a manner that as the lever is, say, depressed the
weight will be raised. A catch is provided for holding the chain during the time
that the lever is being moved back ready for the next lift.
The apparatus hereinbefore described is of especial use for raising the plates for
ships bottoms into position for riveting and when so used 1 advantageously
suspend the hoisting apparatus from a kind of tripod having clips at the ends of
the legs, by means of which the said tripod may be readily secured to the floor-
beams of the ship.

page_text: To enable my invention to be fully understood will describe the same with
reference to the accompanying drawing, in which :-
Figure is a front elevation of my improved raising and lowering apparatus
mounted upon the tripod which I advantageously use in connection therewith:
Figure 2 is a side elevation; and,
Figura 3 is a vertical section:
Figures 4 and 5 are views illustrating the construction of the chain.
a indicates the chain which may be of any desirable length according to the
height or depth to which a weight has to be raised or lowered, and which is
provided at one end with a hook or other suitable device for attachment to the
weight. This chain is composed of plates of the shape shewn in Figure 4, which
plates are arranged singly and in pairs alternately, as shewn in Figure 5, c, c being
the teeth of the chain.
d is the sheave or pulley over which the chain passes, the surface of the said
sheave being shaped to correspond with the chain, as indicated by dotted lines in
Figure 3, and e is the frame or stirrup in which the said sheave or pulley is
mounted, the said frame being provided with a hook f, by means of which the
apparatus may be suspended.
g is the operating lever which is carried upon a pin h in the frame e, and i is the
pawl or catch pivoted at j to the said lever and adapted with its free end to
engage with the teeth of the chain a. k is the catch or detent which is provided
for retaining the chain during the time that the pawli is disengaged therefrom,
the said catch being carried in the frame e by means of a pin l. On one end of the
said pin on the outer side of the frame e is a weighted-arm which serves to
normally maintain the said catch in engagement with the chain.
The operation of the apparatus hereinbefore described is as follows, that is to
say, in order to raise a weight the lever is lifted from the position shewn in the
drawing, so that the pawl i will engage with one of the teeth of the chain above
that with which, in the drawing, it is shewn in engagement; the lever is then
depressed, whereby the chain is drawn around the pulley, and is then again raised
to engage with another link above, the catch retaining the chain during the raising
and so on.
In lowering a weight, the lever is firmly held and the catch is moved out of
engagement with the chain by means of the weighted-arm m; the lever is then
allowed to rise so that the chain passes around the pulley under the action of the
.weight attached to the hook b; when the lever has reached its highest position the
catch is again engaged with the chain and the lever is again lowered (the pawl
having first been pulled out of engagement with the chain) to enable the pawl to
engage with one of the teeth of the chain below that with which it was previously
in engagement; the operation hereinbefore describeil is then repeated. n is a hook
attached to the pawl for enabling it to be drawn out of engagement with the teeth
of the chain during the time that the lever is being lowered.
0, 0, o are the three legs of the tripod upon which I advantageously suspend my
apparatus. The legs o, o are connected at the top by a bolt having an eye
through which the hook may be passed, and the leg o¹ is connected to one of the
legs o by means of a sleeve or collar y provided with a set-screw r, by means of
which the said sleeve or collar may be secured in any position. The lower ends of the
legs o, o are shewn as carried in sockets s, s clipped to the floor-beams t, t of a ship,
and the leg o is represented as provided at its lower end with a clip u adapted to
be directly connected to one of the floor-beams, a swivel-joint being provided
to enable it to be adjusted to any desirable position.
It is to be understood that any other suitable means may be used for carrying
the lifting and lowering apparatus such for instance as a bracket, and when such a
bracket is fixed over a cellar opening it enables the improved apparatus to be used
for lowering and raising casks, cases and the like into and from the cellar: and
that the construction of the chain may vary, provided the arrangement of the teeth
is substantially the same.

page_text: 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 1
claim is
1. Machinery or apparatus for raising and lowering weights comprising a toothed
chain passing over a sheave or pulley, a lever carrying a pawl designed to engage
with the teeth of the chain, and a catch for engagement with the teeth of the said
chain when the pawl is out of engagement therewith, substantially as described.
2. The combination with raising and lowering apparatus of the kind hereinbefore
described, of a tripod constructed substantially in the manner set forth.
3. The manufacture and use of the improved machinery or apparatus for raising
and lowering weights, substantially as hereinbefore described and illustrated in the
accompanying drawing, and with or without the tripod.
Dated the 17th day of December 1890.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.