AN IMPROVED SAFETY CATCH, FOR COLLIERY CAGES AND HOISTS
Year: 1884

page_text: COMPLETE SPECIFICATION. .
We JAMES ALDRED of 30 Wesley Place Chapel Street, Radcliffe in the County
of Lancashire. Colliery Manager. and RICHARD BOARDMAN. of Bank Top, Radcliffe
in the County of Lancashire, Blacksmith do hereby declare the nature of our
invention for AN IMPROVED SAFETY CATCH, FOR COLLIERY CAGES AND HOISTS
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :—
Our invention consists of an arrangement of lever catches and springs applied to
any kind of colliery cage or hoist for the purpose of compelling the cage in the
event of the rope or chain breaking griping the Iron or Wire or Rope or Wood
conductors so as to hold the cage and prevent it falling. And when the cage is
doing ordinary work the lever catches and springs are entirely free from contact
with the conductors. The invention is illustrated in the accompanying figures
1-2-8-4-5.
Figure 1 shews the appliance attached to a cage as in ordinary winding the
catches E. E. being clear of the conductors A. A.
Figure 2-shews the appliance attached to a cage when the rope or chains have
broken and the catches E. E. are griping the conductors A. A.
Figure 3-shews the Lever Catch Ĕ and Spring I as in position when griping
the conductor A, that is after the rope or chains have broken.
Figure 4-shews the Lever Catch E and Spring I as in position when not
griping the conductor A, that is in ordinary winding.
Figure 5-shews in plan the Lever Catch E and Clip G griping the conductor A
and also the Receiving Rods J. J. through which the appliance can pass.
Figure 1 shews the cage in elevation with the conductors A. A. free from the
catches. The rope for raising and lowering the cage is attached to the shackle B
which by means of links C and D is connected with the lever catches E. E‚—
These lever catches E. E. work upon a fulcrum F supported upon the upper
framework of the cage. Attached to the same support is a Clip G. G, which
surrounds the conductor front and back and outside. The end of the lever catch
nearest the conductor works inside the clip G. G. and is arched and toothed as
shewn H. H. Under this arch end of the lever catch is a strong spring I. I.
fastened at one end to the upper framework of the cage. During ordinary work
when ropes and chains are in good condition the links C and D draw up the higher

page_text: end of lever catches and keep them quite free from the conductors. The spring
underneath the lever catches being pressed down by them. In the event of the
rope or chains breaking the links C and D fall and the force of the springs
operating upon the arch ends of the lever catches presses them up, brings them in
contact with the conductors which are pressed against the inside of the clips. The
teeth of the safety catch penetrate the conductor and the cage is held fast.
The curve of the toothed portion of the lever catch is such that the higher the
lever catch is lifted by the action of the spring the further the teeth pierce the
conductor; and also by reason of this curvature the movement gives it greater
clearance from the conductor than would otherwise be the case.
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) A Safety Catch consisting of the combination of enveloping sheath and
gripping levers herein before described as applied to colliery and hoist cages.
2) The particular form of the arch end of the lever catch which increases the
bite as the load increases, the centre from which the arch end is described being
not in the centre line of the lever catch itself, and this form allows more clearance
with less movement of the catch when the cage is in ordinary work.
3) The application of Safety Catches to Iron or Wire or Rope Conductors i
without any projection from the cage interfering with Receiving Rods or other Pit
Shaft arrangements.