Improvements in and connected with Rotatory Shears.
Year: 1896

page_text: Date of Application, 20th Jan., 1896-Accepted, 28th Mar., 1896
COMPLETE SPECIFICATION.
Improvements in and connected with Rotatory Shears.
I, JEAN GOEBEL, of 25 Griesheimer Weg Darmstadt, in the Grand-Duchy of
Hessen, German Empire, Manufacturer do hereby declare the nature of this
invention, und in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention refers to rotatory shears for cutting paper, paste-board, textile
fabrics, and thin sheet metal, in which a fixed rotary knife or knives (i.e. a knife
or knives that cannot be axially displaced) co-operates or co-operate with a
movable knife or knives that is or are constantly subjected to the action of a
spring
or other elastic part pressing the rim or edge of the movable knife against
the rim or edge of the fixed one. In all the rotatory knives (of the sort in
question) known to me up to now the (generally annular) spring or its equivalent
(may be an india rubber ring) is arranged so as to be subjected to compressive
strain, and can (for instance in the case of a renewal) be placed against the
knife only by being shoved upon the shaft of the knife in the longitudinal
direction of said shaft. This is a great inconvenience, as there are often times
several knives upon a common shaft, and one or more of them must then be
removed in order to replace a worn-out spring or ring by a fresh one.
The purpose of my invention is to do away with said inconveniences, and
I attain that object by arranging the spring or rings in such a manner that they,
first, are subjected to tensile strain, and, second, may be placed against the knives
by being laid around the shaft, or around the naves, bearings or supports of the
said knives.
a
In the form of construction shown in the drawing designates an annular
knife that is arranged within a somewhat broad groove of the support R. Said
groove is formed by a ring screwed to the support R, and by a flange c forming
part of said support; but, if preferred, the case may be reversely, i.e. the ring b
may be made integrally with the piece Ŕ, whereas the flange c may as a detachable
part be screwed or otherwise secured thereto.
The inner side or surface of the flange c is inclined or sloping, and serves as a
support for a spring d the two ends of which are connected by any suitable means
after said spring has been put under tension. Owing to the tensile strength
which the spring is thus exposed to, and to the obliqueness of the flange c, the
spring d tends constantly to contract, and to press the knife a against the ring b.
If, on the other hand, the knife a is pressed off said ring, the spring d is expanded,
and the tensile strength correspondingly increased. Said expansion, or increase
of strength respectively, is practically perfectly uniform throughout the whole
length or circumference of the spring, as any inequalities compensate by
themselves.
If, therefore, the supports, bearings or naves R are displaced upon, or together
with the spindle a, the movable knives a are elastically pressed against the fixed
(compare the preamble) knives A (arranged upon the shaft y) and the pressure
between the two knives A a of each set will be practically exactly uniform at
every point of the circumference of said two knives. If, further, a spring is to
be exchanged, the two ends of the same need simply be disconnected, when the
worn-out spring may easily be removed, and the fresh one in the same way be

page_text: put, and secured, in place. There is no necessity of removing one or more of
the supports R.
Owing to the latter with their knives and springs (or india-rubber rings, as d²,
Fig. 2) forming each a complete set that is independent of the other sets, as well
as of the spindle a, the distance between two neighbouring knives a a may be
altered according to any requirement, for instance by means of intermediate
collars or rings arranged between the supports R, or by wedges or keys inserted
between the spindle and each of said supports. Other means may as well be
employed, and, if desired, each of the said pieces R may be arranged upon a
special spindle or bolt.
x
The inclined support c for the helix d, or india-rubber ring, or other
equivalent means, need not indispensably be formed by a portion of the bearing
or nave R, but may form part of the knife a; it may, however, as well be
formed by a special part or parts arranged between the flanges of the bearing or
nave R, or within the groove of the latter respectively. Said part or parts form,
or contain, the groove for the reception of the spring; said groove must, however,
in any case be provided with at least one inclined side, as will now without further
explanation be clear to every one versed in the art in question. I wish, however,
to call special attention to the fact, that the support R proper may in some cases
be entirely dispensed with, in that the knife is then situated directly upon the
spindle with any play sideways, limited by fixed collars or by any other parts
(shoulders) fastened upon the spindle x. One of the collars, or the knife, or one
of the collars and the knife, or the shoulders of the spindle, are in that case
furnished with the inclined surface that forms part of the groove for the reception
of the spring.
For the sake of completeness I wish finally to remark that the spring or ring d
or d may, if desired, have its ends constantly connected, so that it is then to be
shoved over or upon the spindle a, but cannot any more be laid around said spindle.
. There remains still the most important advantage, that the ring is subjected only
to tensile strength, and acts with great uniformity throughout the whole of its
length.
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 :-
In rotary shears, the combination with an axially displaceable counter-knife,
and with means for limiting the axial displacement of the same, with an annular
spring or its equivalent arranged so as to be subjected to tensile strength;
a flange, collar, or ring, having an inclined surface or side forming the support
for said spring; the latter tending constantly to contract, and glide down upon
said inclined surface or. side so as to press upon said counter-knife in the axial
direction of the latter, substantially and for the purpose as described.
Dated this 20th day of January 1896.
J. P. BAYLY,
18 Fulham Place, London, W., Agent for the Applicant.