Improvements in Slip Hooks.
Year: 1897

page_text: Date of Application, 16th Aug., 1857-Accepted, 18th Sept., 1897
Improvements in Slip Hooks.
We, LOUIS HERDLE, late of Philadelphia, U.S. America, at present of
Weingarten in the Grand Duchy of Baden, Germany, Confectioner, and JULIUS
VAN VENROOT of Karlsruhe also in the Grand Duchy of Baden, Germany,
Electrical Artisan, 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 subject of this Invention is a hook-shaped or link-shaped locking contrivance
which by a pulling action, applied through a cord or something similar, can be
instantaneously disengaged.
The practicable completed form represented by way of example in one figure in
the accompanying drawing exhibits such an instantaneously opening locking-link
as it can come into direct employment for rope or chain traction for an entire
series of special purposes, whilst an appropriate modification of shape at the
working point of the material used in traction, renders the appliance also
serviceable for belting or band traction.
It consists principally of a solid rod or pin (A) forming a shank for the parts
which are to be conjoined, and such two parts, the hook (13) and the latch (C) which
move round certain pivots (a) and (a 1) in the shank.
A spring (1) presses constantly against the latch (C) and in the unfastened
condition pushes it forward until further movement is stopped by a stud (E).
Through pulling back the latch (C) by means, for example, of a screw-ring (F)
which is screwed into the latch, the hook (B) after passing the points (B 1)
and (C) is left liberated and thus the metal locking-link which these two parts
when conjoined maintain is instantaneously set open.
The work of unlinking is extremely trifling and the retractive power needed
wholly inconsiderable, while the firmness of the closure of the hook and latch
gives absolute security.
The spring (D) must be chosen of such a strength as will not permit the latch (C)
to make any backward movement which might result from the occurrence of
natural or accidental vibrations, or the temporary loosening of the hook through
momentary slackening of the traction.
The closing of the disengaged hook is effected simply by pressing the hook (B)
toward the stationary shank (A). This, and the entire open position are shown
by dotted and hyphened lines in the figure. The arrows in the drawing denote
the direction of the movements of the single parts when performing their functions
which come under consideration.
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:
An instantaneously opened locking-link its specially distinguishing features
being that on a stationary shank (A) two movable parts a hook (B) and a latch' (C)
are fixed pivoted in such a way that the latter constantly under the action of a
spring is pressed toward a stud (E) which bounds the limit of this pressure; that

page_text: free movement of the hook (B) is restrained by the latch (C), and the latter cannot
sliv, out of place, while against the movement needed to open the latch (C) but a
trifling resistance has to be encountered and overcome.
Dated this 14th day of August 1897.
LOUIS HERDLE.
JULIUS VAN VENROOŸ.