Improvements in Spring Jaw Traps for Catching Animals.
Year: 1897

page_text: Date of Application, 20th May, 1897
Complete Specification Left, 27th Jan., 1898-Accepted, 26th Mar., 1898
PROVISIONAL SPECIFICATION.
Improvements in Spring Jaw Traps for Catching Animals.
I, HUGH LAING MAINLAND, of 31. Moray Place, Dunedin, in the Colony of New
Zealand, Mechanical Engineer, do hereby declare the nature of this invention to
be as follows:―
The object of this invention is to produce a spring jaw trap the chief advantages
of which are, lightness compactness, having few parts, that can be produced
cheaply, and be easily repaired, having great holding power, that cannot be
blocked with loose sand or soil, and that does not wrench off the limbs of animals,
when caught.
In this trap, the springing platform is formed of two parts placed end to end,
between the jaws, keeping the jaws apart, when set, the said jaws pressing against
them. When these plates are depressed in the middle the least thing, they collapse
and the trap acts.
This same platform is also suitable for setting and springing any form of exist-
ing jaw traps, and is simpler than most, and very effective.
My trap consists of jaws having a spring preferably at one end one end of which
forms one pin on which the jaws work at one end, the other end working on a
swivel pin preferably split, which is connected to a chain and pin, or stake, for
holding the trap.
Figure 1, shows the trap open and set ready for use.
Figure 2, is a side view of same.
Figure 3, shows the trap partly sprung, and the action of the spring.
A, are the jaws B, the plates which may be hinged as a stop hinge in the centre,
and be loose from the jaws, or may be loosely hung to the jaws, and when depressed,
separate in the centre, as shown, a small piece B₁, is to facilitate setting and to
keep the edges steady till the trap is sprung.
C, is a double, barrel shaped, conical spiral spring, one end of which forms the
pivot of one side of the jaws, and the other end of which presses against a washer
which has an oval hole to allow it to slide up the jaws when the trap is sprung,
preventing the trap opening, till reset. D, is any chain connecting the trap to the
stake F which is preferably of half tube, or cheesescoop section. E, is a pin or
split-pin forming a swivel connecting the chain D, to the trap and forming the
other pivot to the jaws.
The jaws are bent downwards to grip better.
It is obvious that this form of platform is adaptable to any form of existing jaw
trap, the principle being that of two cones with small bases placed together and
the apexes at the outside ends, so that the smaller the bases the easier the plates,
(or cones) collapse.

page_text: For convenience these plates are made of even thickness while having the action
as above.
The connection between the chain and the stake, may be a swivel similar to E.
Dated the 13th day of March 1897.
G. F. Redfern & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements in Spring Jaw Traps for Catching Animals.
I, HUGH LAING MAINLAND, of 31, Moray Place, in the City of Dunedin, in the
Colony of New Zealand, Mechanical 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:-
The object of this invention is to produce a spring jaw trap the chief advantages
of which are, lightness, compactness, fewness of parts, that can be cheaply pro-
duced, easily repaired if necessary, that has great holding power, that cannot be
blocked with loose sand or soil, and one that does not wrench off the limbs of
animals that are caught by it.
In this trap, the springing platform is formed of two principal parts, placed
end to end, between the jaws, for keeping the jaws apart, when set, the said jaws
pressing against them. These plates are so adjusted that they collapse with a
slight amount of pressure from above, and when the parts forming the platform
are depressed the least thing, they fall away and the trap acts.
This same platform is also suitable for setting and springing any form of existing
jaw traps, and is simpler than most, and very effective, doing without the various
lever mechanism usually employed for that purpose.
My trap consists of jaws having a spring preferably at one end formed so as to
slide up the closing jaws on one side of them, one end of this spring forms one pin
on which the jaws work at one joint; the other joint of the jaws working on a
swivel pin, either split or bent and as a rivet, to the eye of which is connected a light
chain and stake for holding the trap, it being so light that all but the smallest
animals would run away with the whole.
Referring to the drawing lodged with the Provisional Specification, No. 12538/97.
Figure 1, shows the trap open and set and ready for use.
Fig. 2, is a side view of the same.
Fig. 3, shows the side view of the trap as partly shut and partly open, for
illustrating the climbing action of the spring up the closing jaws, and it will be
there seen that the circular spring pressing upward offers a very strong resistance
to opening the jaws.
A, are the jaws preferably slightly bent downwards at the teeth to ensure a
stronger hold.
B, B, are the plates forming the platform which may be hinged as a stop hinge
in the centre, and if so would be stopped when very slightly above a straight line
so as to be easily depressed with slight force, or they may be loosely hung, one to
each of the jaws and when depressed, separate in the centre, as shown.
B¹, is either a small piece riveted on or a small projection from one plate for
stopping the plates from springing or collapsing when pressed from below, and also
to facilitate the setting of the trap, and to assist in keeping the edges of B, B,
steady when the trap is set.
C, is a conical spiral spring preferably barrel shaped so as to lie flat or nearly
so when in use.

page_text: The lower end of this spring forms a jaw pivot and the upper end presses an
oval washer up the side of the jaws, the washer merely being to take the strain
off the light spring, otherwise it is unnecessary.
D, is any swivelled chain connected with the other jaw pivot E, at one end and
to the stake F, at the other end. It is obvious that this double plate platform.
would suit existing spring jaw traps, being formed on the principle of two cones
with very small bases placed together and the apexes pressing against the open
jaws, so the smaller the bases, the easier the plates collapse, care being taken not
to make them act too easily.
It is obvious that the stake is of great use in mooring a light trap and preventing
loss and that the crescent or half circle section is the strongest and lightest con-
venient section, another feature is, that when the double platform is hinged
together and not attached to the jaws, the whole falls clear of the trap when same
is sprung but may be loosely attached by such as a chain to prevent loss, of the
said platform.
The whole may be of any suitable sizes or materials.
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:
1. In a spring jaw trap for catching animals the combination of hinged jaws
usually hooked downwards, (such as A, A,) with a conical or barrel shaped spring
(such as C,) bent to form a hinge pin to keep it and the jaws in place, and formed
to slide up the side of the jaws in springing the trap, and the combination with
a double platform (such as B, B, B',) substantially as described and explained and
as illustrated in the drawing.
2. The combination with any spring jaw trap of a double hinged platform, or
plates either hung to the jaws or hinged together, in either case pressing the jaws
open till collapsed by pressure from above, only, (such as B, B, B',) and also of a
semicircular or crescent section stake (such as F,) attached to the trap by a swivel
chain for mooring the trap substantially as described and for the purposes specified,
and as illustrated in the drawing.
H. L. MAINLAND.
G. F. Redfern & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.