IMPROVEMENTS IN SLIP-HOOKS OR SLIP-LINKS AND IN APPARATUS TO BE USED IN CONNECTION THEREWITH FOR RELEASING BOATS "
Year: 1883

page_text: LETTERS PATENT to Henry Bezer and Philip Alexander Thomas both of the
Westminster Bridge Road in the County of Surrey Engineers for an
Invention of "IMPROVEMENTS IN
SLIP-HOOKS OR SLIP-LINKS AND IN
APPARATUS TO BE USED IN CONNECTION THEREWITH FOR RELEASING BOATS
"
PROVISIONAL SPECIFICATION left by the said Henry Bezer and Philip
Alexander Thomas at the Office of the Commissioners of Patents on the
2nd November 1883.
"
HENRY BEZER, and PHILIP ALEXANDER THOMAS, both of the Westminster
Bridge Road in the County of Surrey, Engineers, IMPROVEMENTS IN SLIP-
HOOKS OR SLIP-LINKS, AND IN APPARATUS TO BE USED IN CONNECTION THEREWITH
FOR RELEASING BOATS,"
Our Invention has reference more particularly to slip-hooks of the kind which
consist of a body part, of an arm or link pivoted to the said body part and of a
latch for retaining the said arm or link this latch being also pivoted to the body
part; and the object of our first improvement is to adapt the slip-hooks to the
purpose of lowering or suspending weights or bodies, and to make them self-
releasing so soon as the body or weight ceases to act thereon. With this object wo
construct the pivoted retaining latch with a greater weight, spring or other device
acting upon the latch so that the latch when not forcibly retained by the corre-
sponding part of the pivoted arın or link is moved by such greater weight or
spring and the link or arm is no longer held. So long as a body is suspended from
the slip-hook, the weight of that body keeps the retaining latch and the pivoted
arm in gear; but so soon as the body touches the ground or other support, and its
weight is thereby taken off the hook, the latch is automatically moved out of gear,
the arm swings and the body is released. Whilst a body which is to be lowered
or suspended is being attached to the slip-hook, and until its weight begins to act
upon it, the retaining latch is held in gear by hand or otherwise. Or we construct
the latch so that the action of the weight or spring can in a moment be trans-
ferred from one side of the pivot thereof to the other, thus converting the slip hook
from an automatic hook to a snap action retaining hook. As a security and for
[Pavine

page_text: enabling bodies which are being lowered to be deposited in a particular position,-
such for instance, as blocks in building or bales in warehousing, we employ a
safety pin or lino which is passed through holes in the side plates or frame, and
through a corresponding hole in the retaining latch which comes opposite the side
plate holes when the latch is in gear. By this means the automatic releasing of 5
the pivoted arm or link is prevented until such time as the pin or line is withdrawn
and the weight of the body ceases to act on the hook.
Where the slip hook is required to release easily under all circumstances, and
the latch is working in the same plane as the arm the surfaces of the catches where
they gear should be made on a curve having a radius which is struck from the 1
centre of the pivot on which the retaining latch works.
But where it is preferable to impede this releasing action while any strain or
weight is on the slip-hook-such for instance as in the self-releasing hooks,-the
surfaces of the catches where they gear should be undercut, the front of the tooth
or catch on the latch being nearer the pivot than the back thereof.
Where a slip-hook has to rest with its side against a surface we construct it so
that the pull or action for effecting the disengagement or release is away from that
surface, the retaining latch moving in a plane across that in which the pivoted
arm swings.
In situations where the action of the slip-hook is confined and it is necessary to
effect the disengaging movement of the latch by a pull outwards, i.e. in the same
direction as the movement of the pivoted link, (such for example as in its
application to the bames of single and other harness): or, where it is required to
have the arm projecting like an ordinary open hook for convenienco in looking-
on, such as in butcher's hooks; we make the pivoted arın double, the retaining
latch being made to gear to the end of the second or additional portion instead of
to the end of the main arm, as is usual.
In all cases we place the pivoted retaining latch in such relation to the pivoted
arm that there is no tendency on the part of any weight or strain on the arm, to
throw out of gear the retaining latch.
In cases where it is unnecessary or undesirable to use a spring or weight where the
strain on the slip hook is not constant, we employ a strap, lace, rope or pin which
is passed through the frame and retaining latch to prevent the latch dropping out
of gear when its connections are slack or vibrating. From the construction of the
catches in relation to one another as described above, the lace or other device can
always be readily withdrawn before disengaging the latch.
When it is required to have a very narrow slip-hook we make the latch with a
straight tail which lies along the frame or body part parallel to the direction of
strain. To keep the latch from shaking out of gear we employ either a strap laco
rope or pin as above described or an india-rubber ring embracing the frame or side
plate as well as the tail of the latch.
⠀
For slip hooks which have to be released at a point out of reach-such as towing
or mooring slips-we employ a rope or chain the ends of which act respectively
on the latch on different sides of the pivot. By keeping a strain on the one the
latch is kept in gear even if the connections are alack, while by pulling the other
the latch is released.
In constructing slip attachments for straps we make our slip link in two parts,
the one consisting of an outer frame or guide in which the other. slides freely.
The frame or guide has a latch pivoted to it which engages in a suitable recess in
the sliding portion or second part in such manner that it locks the latter within
the frame. The latch is.made so that it can be easily withdrawn under strain thus
releasing the sliding part, and it is protected from being disconnected by vibration
or from extraneous-objects.
In some cases we fasten the rope or chain from which our slip link is depending
to the portion of the latch itself on the other side of the pivot to the catch, using
the body part or frame as a mere connection between the two pivots. The effect
gear. A
of this is that any weight or strain on the hook keeps the catches in
1

page_text: disengaging line or chain is attached to the latch on the side where the tooth or
catch is, the pull on which can only take effect when the inain rope slackens.
For releasing boats where a slip hook is attached to the end of each davit-fall,
we fit the boat with a sliding fore and aft pennant led through suitable guides, and
having at its extremities at bow and stern eyes hooks rings or other attachments
into which the slip-books can be coupled-At the bow and stern of the boat
respectively is attached a short chain or rope. The slip-hooks are so constructed
that the other end of the chain or rope can be attached to the retaining latch of the
slip-hook. When the boat is ready for lowering, the slip-hooks are coupled up to
the eyes or other attachments at each end of the sliding pennant and the short
chains are attached to the retaining latches of the slip-hooks, When the boat is
lowered and becomes waterborne, the slip hooks are released either automatically
or by forcibly disengaging the retaining latches. But should, from any cause, only
one hook be released, the sliding pennant will run out from the released end, and
as the boat draws away from the davit-fall, it causes the short chain attached to
the unreleased slip-hook to pull upon the retaining latch of that hook and disengage
it. The frame of the slip hook is so constructed that it forms a guard covering
that portion of the latch (to which the releasing chain is attached) and the chain
in such a manner that the chain cannot free itself from the latch until after it has
pulled the latch out of gear, and thereby released the slip-hook. Should the boat,
from being lowered faster at one end than the other or from any other cause, slide
along the pennant until the slip hook at one end of the boat fouled that part of the
boat through which the ring or other attachment at the end of the pennant passes,
the slip hook is so constructed that a sufficient movement of its arm or link can
take place to ensure its release from the sliding pennant.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Bezer and Philip Alexander Thomas in the Patent Office
on the 2nd May 1884.
HENRY 'BEZER and PHILIP ALEXANDER THOMAS both of the Westminster
Bridge Road in the County of Surrey, Engineers "IMPROVEMENTS IN SLIP- 5
HOOKS OR SLIP-LINKS AND IN APPARATUS TO BE USED IN CONNECTION THEREWITH
FOR RELEASING BOATS"
Our invention has reforonco more particularly to slip hooks of the kind which
consist of a body part, of an arm or link pivoted to the said body part, and of a
latch for retaining the said arm or link this latch being also pivoted to the body 1
part. In some of our improved slip hooks or slip links the arm or link is
constructed as a single bar with one end pivoted to the body part and having its
other end engaging with and controlled or retained by the latch which is provided
with a projecting tooth or catch for that purpose. In others of our improved slip
hooks or slip links the arm or link is constructed as a double arm having 2 arms 1
extending from the pivoted portion of the link one arm being used to support and
carry the weight or body attached to the slip hook and the other or second arm
being controlled by the latch against which it butts. In all cases the retaining or
controlling latch is placed in such relation to the pivoted arm that there is no
tendency on the part of any weight or strain on the arm to throw the latch out of
gear, and the latch is made according to requirement so as to move either in the same
plane as that in which the arm or link moves or across that plane. Where necessary
the body part or frame is constructed so as to thoroughly guard the latch from
being knocked out of gear by contact with extraneous objects and is made preferably
in 2 portions the latch and arm working between them.
The object of our first improvement is to adapt slip hooks or slip links of the kind
above referred to to the purpose of lowering or suspending weights or bodies and
to make them self releasing so soon as the body or weight ceases to act thereon.
With this object we construct the pivoted retaining latch with a weight spring or
other device acting upon it so that when not forcibly retained by the corresponding
part of the pivoted arm or link it is moved by such weight or spring and the arm
is no longer held; in other words the normal position of the latch is out of gear
that is beyond the radius described by the pivoted arm.
Figure 1 of the annexed drawings is a face view of a self releasing slip hook
constructed according to this part of our invention a portion of the body part or
frame being removed to show the positions of the latch and arm working within
the body part. A is the arm or link, B the body part or frame and L the latch.
The latch has a weight W acting on it so that it causes it to assume the position
shown in the figure that is beyond the radius described by the arm A and allowing
the arm A to swing on its pivot clear of the projecting tooth or catch C of the
latch. The latch is also provided with a portion F which can be taken hold of by
the hand or finger. When a body is to be attached to this slip hook the latch Lis
held in the ingear position by grasping the part F and thereby holding up the
weighted part W. The ring or attachment of the body to be suspended-is then
passed over the arm A and the latter is snapped into gear with the latch L.
Until the weight of the body thus attached begins to act on the slip hook the latch
is still held in gear by hand or by applying a safety pin, lace or wedge to the latch
so as to hold it in the ingear position. As soon however as the weight of the
attached body begins to act upon the slip book the weight of that body holds the
latch in gear with the pivoted arm. But when the body touches the ground or
other support and the slip-hook is thereby relieved of its weight, the latch L

page_text: automatically assumes its normal or out of gear position, the arm A swings open
and the body is released. For enabling bodies which are being lowered to be
deposited in a particular position such for instance as blocks in building or bales in
warehousing the pin P can be left in the holes H until the body is in the exact
position required, when the pin being withdrawn the arm A swings open and the
body is released. Figure 2 shows an edge view and Figure 3 a side view of the
same self releasing hook coupled up and with the body X suspended from it. p is
the safety pin above mentioned and H are the holes to receive this pin.
Figures 4 and 5 shew in the out-of-gear and in-gear positions respectively a
self releasing slip hook acting in the manner above described but having the weight
suspended from the first arm A of the double arm A A' and the latch L actuated
by a spring S instead of by a weight. Letters of reference the same as those in
Figures 1, 2 and 3 indicate corresponding parts.
In our self releasing slip hooks we make the surfaces of the latch L and arm A
where they gear undercut as is clearly seen in the Figures already described, the
front part of the tooth or catch on the latch being nearer the pivot than the back
thereof thus impeding the action of the weight on the latch and preventing it
acting too readily and releasing the arm before its proper time.
For some purposes we construct or arrange the latch so that the action of the
weight or spring can at once be transferred from one side of the pivot thereof to
the other, thus converting the slip hook from a self releasing hook to a snap action
retaining hook or vice versa. Figure 6 represents a slip hook constructed in this
manner. Ris an india rubber ring embracing the frame B and the tail of the
latch L that is to say that portion of the latch which is on the opposite side of the
pivot P to the catch or tooth C. The elasticity of the ring R causes the latch L
always to tend to the in-gear position giving the slip hook a snap retaining action;
but by slipping the ring R along the frame B to the other side of the pivot P
where there is a recess D in the frame as seen in Figure 7 the ring presses on the
latch Land causes it to tend to the out-of-gear position thus making the hook self
releasing.
Figure 8 shows how we apply a shifting weight to the latch for the same purpose
W being the weight free to be moved on a subsidiary pivot E so that it can as
desired be made to act on either side of the pivot P of the latch.
Figure 9 shows the application of a spring S which can be shifted as desired to
either side of the pivot P of the latch.
Figures 10, 11 and 12 illustrate the manner in which we construct a self-acting
slip-hook suitable for butchers or for situations where an open hook is desired for
convenience in hooking on. Figure 10 shews the hook ready for receiving the
carcase or weight it has to support, the india rubber ring R or similar device being
made to act so as to keep the latch L in gear with the second arm A¹ of the
pivoted double arm A A¹ which has its other arm A in the form of a pointed hook.
Figure 11 shews the slip hook supporting the body M which acts upon the latch L
so as to compel it to remain in-gear as above described. While the body is so
suspended the india rubber ring R is slipped up the frame B to the other side of
the pivot P of the latch and thus sets the latch ready to assume the out-of-gear
position whenever the weight of the body suspended from the slip hook is relieved,
which enables the arm A to swing over to release the body M. H is a hole in the
frame to receive a safety pin as an additional security when hooking on. Figure 12
shows the slip hook released in the manner aforesaid.
Where a slip hook has to rest with its side against a surface or too close to allow
of free action of the hand when releasing we construct it so that the pull or action
for effecting the disengagement or release is away from that surface the retaining
latch moving in a plane across that in which the pivoted arm swings. Figures 13
and 14 illustrate a hook thus constructed, Figure 13 being a side view and Figure 14
a plan or top view with the parts in gear Figure 14 also showing in dotted lines
the position of the parts when released. A is the arm, B the body part and L the
Jatch; this latch is pivoted to the body at P and is made to move in a plane across

page_text: :
that in which the arm A moves as clearly seen by the dotted lines in Figure 14.
To prevent the latch shaking out of gear when coupled up a strap or lace attached
to the latch or to the body part is passed through holes in the latch and body part
which come opposite each other when the latch is in gear. This strap or Ince is
shewn at S and can always be withdrawn easily as there is no tendency on the part
of the arm when under strain to move the latch. A spring may, equally well be
employed to keep the latch in the in-gear position.
Figure 15 shows a slip-hook which we construct for situations where the action
of releasing must be performed by a pull on the latch L in the same direction as
the pivoted arm A. The arm A is here made double the latch L gearing into the
second arm A¹ Figure 16 shews the same hook with the arm. released by
withdrawing the latch L by means of the finger hole F. The latch L can be kept
in the in-gear position by a lace passed through the holes H in the manner above
described or by a spring.
In all cases where the slip hook is required to release easily under strain and 1
where the Intch is working in the same plane as the arm we prefer to make the
surfaces of the catches where they gear (at C in the figures) on a curve-as seen
in Figures 15, 16 and 17-having a radius which is struck from the centre of the
pivot P on which the latch L works.
Figure 17 shews a slip-hook which we make for situations where it is desirable
to have a very narrow slip hook. The tail piece T of the latch L, which is used
as a means of disengaging the latch by taking hold of the thumb piece F (which
projects beyond the body part B), is made straight and lies along the body part B
parallel with the direction of the strain on the slip-hook.. R is an india rubber
ring embracing the body part B and the tail of the latch L in order to keep the 2
latter in gear. The same result may be gained by passing a lace through the
holes H as previously described.
For slip-hooks which have to be released at a point out of reach-such as
towing or mooring slips-we employ a rope or chain the ends of which act
respectively on the latch on different sides of the pivot. By keeping a strain on 3
the one the latch is kept in gear even if the connections are slack while by pulling
the other the latch is released. Figure 18 shews a slip hook thus constructed.
On the latch L is a thimble M to which we connect the ends of the rope N N'.
By keeping a strain on the rope N¹ the latch is kept in gear with the arm A even
if the connections are slack. On the other hand by pulling the rope N the latch 3
is released. The ropes aro led through eyes or holes OO in the frame B. H is a
hole for a pin to fix the latch L in the in gear position when required.
For some purposes such for instance as slipping anchors we fasten the rope or
chain from which the slip link or slip hook depends to the portion of the latch
itself on the opposite side of the pivot to the catch, using the body part or frame 4
as a mero connection between the 2 pivots; the effect of which is that any weight
or strain on the hook keeps the catches in gear. A disengaging line or chain is
attached to the latch on the side where the tooth or catch is, the pull on which can
only take effect when the main rope slackens. Figure 19 represents a slip-hook
constructed in this manner the catches being in gear and Figure 20 shows the 4
same hook with the catches released or out of gear. H¹ is the main hawser or
chain attached to the end of the second arm L' of the double armed latch L L'
the angle which the second arm L¹ makes with the first L being such that when
the latch is in gear the line of strain passing through the pivot of the latch passes
just within the end of the arm A. The strain therefore always tends to keep the 5
latch tight in gear. To the end of the first arm L is attached a second and lighter
chain H. When it is required to release the catches, the second chain H² is made
fast and the main hawser H¹ is allowed to run slack, the strain will thus pull the
latch out of gear by itself. The body part A serves as a connection between the
pivots as well as a guard and stop to the latch and is preferably made solid while
the latch is made looped. Whilst the strain is on the main lawser the latch
cannot possibly be pulled out of gear. In cases such as for cargo work where the

page_text: body suspended from the slip hook may become supported at an undesirable
moment and it may be desired to impede the release of the catches until the
chain H is pulled upon we pass an india rubber ring R around the arm L' of the
latch and around a projection Z of the body part B; this ring holds the parts in
gear until the arm L' and projection Z are separated-as seen in Figure 20-by a
pull upon the chain H². When it is required to make this slip hook self acting
the projection Z may be placed lower down the frame or body part-as shown in
dotted lines at Z-; the elasticity of the rubber ring R will then cause the latch L
to tend to the out-of-gear position.
For releasing boats where a slip-hook is attached to the end of each davit-fall
we fit the boat with a sliding fore and aft pennant led through suitable guides
and having at its extremities at bow and stern eyes, hooks, rings or other
attachments into which the slip hooks can be coupled. At the bow and stern of
the boat respectively is a short chain or cord and the slip hooks are so constructed
that the outer end of the chain or cord can be attached to the retaining latch of
the slip hook. When the boat is ready for lowering the slip hooks are coupled up
to the eyes or other attachments at each end of the sliding pennant and the
short chains are attached to the retaining latches of the slip hooks. When the
boat is lowered and becomes waterborne the slip books are released either
automatically or by forcibly disengaging ‘the retaining latches. But should from
any cause one hook be released the sliding pennant will run from the released end
and as the boat draws away from the davit-fall it causes the short chain attached
to the unreleased slip hook to pull upon the retaining latch of that hook and
disengago it. The frame of the slip hook is so constructed that it forms a guard,
covering that portion of the latch to which the releasing chain is attached and.
the chain, in such a manner that the chain cannot free itself from the latch until
after it has pulled the latch out of gear and thereby released the slip hook.
Figure 21 represents a boat fitted with a pair of our self-releasing hooks and with
a sliding fore and aft pennant as above described. Figures 22, 23 and 24 represent
one of the releasing hooks on a larger scale. A is the arm or link which can bo
snapped in whether the latch is fixed by the safety pin or not. B is the body
part or framo consisting of 2 plates kept at the right distance apart by the
shackle d at top and distance pieces e at the bottom of each leg. L is the latchi
having a second arm with its end T projecting outside the frame B. H is the
hole for the reception of the safety pin to fix the latch if desired. E E are the
legs of the frame B which prevent the arm A getting jamined on the upper sido
of the thwart ✗. G is the guard to the tail piece T of the latch L. This swivels
on its pivot g in order to attach the pull off cord C and is fixed by a second pin pp.
P is the sliding pennant. C is the pull off cord with an eye or hook at one end to
slip over the tail piece T and it can be provided with a weight W which will give
an automatic action to the latch or will jam on the underside of the thwart X and
pull off the latch L forcibly if anything sticks. This cord C is made of such a
length that when one hook becomes released the pennant P at the released
end will have to disappear beneath its thwart X before the weight W of the other
cord C jauns in the other thwart and pulls the second hook off. The cord can be
fixed to the thwart where automatic action is not required. The guard G is made
sufficiently long so that the eye of the weighted or fixed cord C is prevented from
slipping off the tail piece T till it has completely reloased the latch L from the
arin A. It will clearly be seen that when one end of the pennant P becomes
released the other is bound to be released also. The extended legs E of the body B
make the boat free to slide along the pennant to its farthest limit when suspended
without bringing a strain to bear on the cords C, the action being that the legs E
jan on the thwart X and the pennant cannot go below the thwart while coupled
up. These extended legs also enable the latch L to bo released whether the legs
are tight down on the thwart or not.
The sliding pennant should have at each end below the big eye V for coupling
into the slip hook a second eye V¹ which may be used for the purpose of inserting

page_text: 64
a thowl pin to keep the ends of the pennant standing up above the thwart when
coming alongside. The falls can then be sent down with the slip hooks already
'made up," that is, with the latch and arm in gear. A "dab" down on the
temporarily fixed eye of the penuant would then be sufficient to make the arm A
recede within the frame and fall back in position after passing through the eye of
the pennant and coupling it to the slip hook. When coming alongside if the man
at one end of the boat fail to attach the pennant to the slip-hook on the davit fall
it may be desirable in a .heavy sea to release the boat from the other davit-fall.
This can be effected by pulling upon the cord C at that end and forcibly
disengaging the slip hook.
Having now described the nature of our said invention and in what manner the
same is to be performed we declare that we claim :—
1. Constructing slip hooks or slip links of the kind herein referred to with a weight
or equivalent device acting upon the latch in such manner as to release the latch
automatically when not retained in gear by the effect of a weight or body suspended 1
to the pivoted arm or link, the normal position of the latch being out of gear
substantially as and for the purpose hereinbefore described.
2. Constructing slip hooks or slip links of the kind herein referred to in such
manner that the action of a weight or spring upon the latch can at once be
transferred from one side of the pivot thereof to the other thus converting the
slip hook from a self releasing hook into a snap action retaining hook or vice
vered substantially as here-in-before described.
3. Constructing slip hooks or slip links with the retaining latch made to attach
to the suspending chain or rope on the opposite side of the pivot to the catch, and
with a disengaging line or chain attached to the latch on the other side of the
pivot substantially as hereinbefore described with reference to Figures 19 and 20.
4. The various constructions and arrangements of slip hooks or slip links
respectively shown in the annexed drawings and hereinbefore described.
6. The employment in connection with slip hooks or slip links for releasing
boats of a sliding fore and aft pennant arranged and acting substantially as
hercin before described.
In witness whereof I the said Henry Bezer for myself and on behalf of the
said Philip Alexander Thomas have hereunto set my hand and seal this
thirtieth day of April One thousand eight hundred and eighty four
HENRY BEZER (L.S.).