A New or Improved Disengaging Clutch for Boats and other Articles.
Year: 1894

page_text: Date of Application, 23rd May, 1894-Accepted, 1st Dec.: 1894
COMPLETE SPECIFICATION.
A New or Improved Disengaging Clutch for Boats and other
Articles.
We, ORBY CECIL MOOTHAM, of 72 Old Christchurch Road, Bournemouth,
in the County of Hants, Umbrella Manufacturer, and HOWARD MARRYAT, of
57 Hatton Garden, in the City of London, Electrical 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 :-
Our invention relates to a new or improved disengaging clutch specially, though
not exclusively, adapted for raising and lowering boats; and it is designed to
automatically disengage the load which it sustains whenever the strain of the said
load is relaxed.
In order that the description of our invention may be more readily grasped we
have appended hereto two sheets of drawings illustrative of our invention. The
figures on Sheet 1 of the drawings illustrate one form of our detaching clutch,
the said form being that which we have hitherto found to give the best results
in practice.
In the said drawings
Figure 1 is a front elevation of our clutch in its closed position, that is to say.
in the position which its parts occupy when the load is being sustained.
Figure 1 is a plan view of the yoke piece J shown in Figure 1.
Figure 2 is a front elevation of the clutch as seen in its open position, that is
to say in the position which its parts, occupy when the load is no longer supported
by the clutch.
Figure 3 is a side elevation of the clutch as seen in its open position.
Figure 4 diagrammatically illustrates a convenient method of applying our.
invention in the case of a boat.
In the figures A A¹ are two levers articulated by the bolt or rivet B so as to
resemble and move relatively to one another in the same manner as a pair of
shears. At the lower or gripping end of the said levers are the jaws CC, in
this case of hemispherical shape and having hemispherical recesses in them similar
to those in an ordinary bullet mould so as to be adapted to grip the spherical
head d of the attaching hook D. At the upper ends of the levers A A' are the
guide wings E E', fitted with the extension pieces e e¹ and having the grooves or
slide ways e². f1 are side arms rigidly attached at their inner ends to the collar
piece F. The said arms ff slide in the grooves or slide ways e² as the parts of
the clutch pass from their open to their closed position and vice versa. The collar
piece F is bored as shown by the dotted lines so as to be free to slide upon the bolt
rod G which latter is terminated at its upper end by the eye g and at its lower end
by the cam shaped part of the part j'. His a spring whose function is to force
the parts into their open position. This spring encircles the shank of the bolt
rod G, its lower end abutting against the cam shaped piece and its upper end
nesting in the recess f² in the lower end of the collar piece F. J is a yoke
piece consisting of two parts and j as shown more particularly in Figure 14,
where they are seen in plan. Of these two parts j is a flat plate of the form
clearly shown in Figures 1, 2, 3 and 4, whilst is a piece of the form shown in
end view in Figure 3, in plan in Figure 14 and in side elevation by the dotted
lines in Figure 2.
It will be seen that the cam shaped piece and the triangular
stud or pin ³ are integral with the part j'. The stud or pin j³ fits in a triangular
orifice in the plate i.

page_text: The action of our invention is as follows. Let us assume that the load is
attached to the hook D. The clutch is brought down, or the hook raised, till the
head d is within the jaws C, C¹. These are then caused to grip the head d by
pressing the extension pieces e, el close up to the collar piece F. The parts are
now in the position shown in Figure 1. If the load is required to hang for a length
of time on the clutch (as for example iu the case of a boat which is to hang on the
davits until required for use), a ring may be passed over the extension pieces so as
to keep them in the position shown in Figure 1, or the parts may be bound in this
position by a cord or otherwise. Let us now assume that the load is to be lowered.
The ring or cord is removed from the extension pieces, but the load is still tightly
sustained, provided the load is sufficiently heavy to overcome the action of the
spring. Indeed the heavier the load the more tightly is the hook D held in the
jaws C, C. As soon however as the load reaches the ground, or the strain of
the load is otherwise removed from the clutch, the spring is no longer overcome
by the weight of the load, but now forces the parts apart into the position shown
in Figure 2, and the load is now automatically released.
When a load is to be raised by means of our invention the action is similar.
Let us assume for example that sacks of flour are being raised from the ground
to the upper floor of a warehouse. The load is hung upon the hook in the
ordinary way and the hook gripped by the clutch as herein before mentioned.
The sack is then raised to the upper floor in the usual manner when as soon as
the strain is taken off the clutch by the resting of the sack on the landing stage,
the spring asserts itself and the sack is released.
In Figure 4 we show a convenient manner of applying our invention in the
case of a boat. d, d are two heads adapted for engagement in the jaws of our
aforesaid clutches. These are connected by a chain or rope passing over the
pulleys K, K. The object of this arrangement as will be understood by persons
conversant with the practice of raising and lowering boats is to obviate the
possibility of one end of the boat being released and the other end still retained.
Suppose that by some means the head at one end of the boat became detached,
it is obvious that the strain on the clutch at the other end of the boat would
be momentarily released so that the spring would force the parts of the clutch
apart and this part of the boat would be released also.
We desire it to be understood that we do not confiue ourselves to the precise
form of clutch illustrated, as it is obvious that it might be considerably altered in
its minor details. The principle of our invention being understood, any competent
engineer could modify the details to an indefinite extent without departing from
the spirit of our invention.
We have herein before stated that Figure 1 represents the parts in their closed
position, that is to say, when a load is sustained. We desire however to add that
the exact relative position of the said parts will depend upon the weight of the
load. Thus, the heavier the load the more will the spring be compressed until,
when a sufficiently beavy load is sustained, the spring is sufficiently compressed for
the yoke piece to come into contact with the guide wings E E'. It. will be
understood, however, that the jaws are completely closed when a load of com-
paratively small weight is sustained.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The new or improved disengaging clutch substantially as set forth.
2. In a disengaging clutch, the employment of two levers arranged after the
manner of a pair of shears and whose jaws are shaped so as to be adapted to grasp
an attaching device (such for example as a book) with a spring for forcing the
jaws apart when the spring is no longer overcome by the strain of the load.
3. In a disengaging clutch, the combination of two levers arranged after the
manner of a pair of shears and whose jaws are adapted to grasp an attaching device

page_text: (such for example as a hook), a spring for forcing the jaws apart and a suspending
device (such for example as an eye) for suspending the clutch.
4. The arrangement and combination of parts substantially as set forth with
reference to Figures 1 to 3 inclusive.
Dated this 23rd day of Mar 1904