Year: 1887

page_text: I, AUGUSTO STIGLER Engineer, residing in Milan Italy 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 :-
The safety apparatus for hoists such as lifts cages and the like forming the object of
this Invention consists essentially of one or more oscillating wings preferably formed
by frames covered with cloth or other light material and so arranged that when the
cage or the like to which they are attached exceeds a certain speed the resistance of
the air acts upon the said wings and by means of a system of levers and weights
brings into action wedges which jam against the guides and retard or arrests the
progress of the cage as hereinafter more fully described.
And in order that my said Invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheet of drawings the same letters of reference indicating
corresponding parts in all the Figures.
Figure 1 of the accompanying drawings represents a plan of the bottom of a cage
provided with a safety clutch according to this invention viewed from below.
Figure 2 is a side elevation of the same and Figure 3 is a detail of one of the
guides illustrating the action of the wedges.
In the example illustrated in the drawing a a represents the frame of the floor of
the cage which works between two vertical posts or guides b b in the usual manner.
This cage is prevented from falling or descending too rapidly from any cause whatever
by means of two wings or blades d d arranged horizontally under the floor being
preferably made as light as possible and consisting for example of a frame covered
with a thin fabric or material offering the necessary resistance to the air. These wings
are pivoted or hinged to the floor at c and are provided with hooked levers or arms e
Figure 2 which engage with projections e' on weights f
These weights are carried on the ends of two pairs of levers goscillating on centres
or pins connected to the floor of the cage. The other ends of these levers g are
connected by short links to wedges i capable of sliding vertically in suitable guides
D

page_text: provided on the sides of the floor frame a in such a position as to act upon opposite
sides of the guide posts b as indicated in Figures 1 and 3.
When the cage is working properly the wedges i are out of contact with the guides
or posts 6 but when from any cause whatever the descending speed of the cage exceeds
the proper limits the resistance of the air acting on the under side of the horizontal
or nearly horizontal wings d causes them to turn on the centres c and move the hooked
levers e with which they form part in such a manner as to release the weights f. These
weights then drop and cause the levers g to oscillate on their centres and bring the
wedges i into action causing them to rise in their guides and jam against the sides of
the posts b thereby reducing the speed of the cage, or stopping it altogether. The
weights may be rendered more prompt in their action by means of springs arranged
under the floor of the cage so as to exert a downward pressure on the levers carrying
the said weights.
Means are provided for regulating the action of the apparatus so that it shall come
into action directly any desired limit of speed is exceeded. For this purpose the ends
of the wings d are supported by a lever provided with an adjustable counterweight <¹
which partially balances the weight of the wings so that by adjusting the position of
this weight the apparatus can be set to come into action at any required speed.
The employment of this safety apparatus does not exclude the simultaneous
employment of other safety appliances in combination with the same cage or lift.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is.
A safety clutch or attachment for lifts or hoists consisting of balanced wings
preferably formed by a frame covered with a woven fabric or other material offering
such resistance to the air that when the speed exceeds certain limits the said wings are
caused to oscillate thereby releasing weights which cause wedges to jam against the
guides and arrest the motion of the lift or cage substantially as herein before described
with reference to the accompanying drawings.
1004