IMPROVEMENTS IN APPARATUS FOR SHEARING AND PUNCHING METAL PLATES AND OTHER ARTICLES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Adolph Julius Lehmann at the
Office of the Commissioners of Patents on the 10th May 1883.
ADOLPH JULIUS LEHMANN of West Hartlepool in the County of Durham
"IMPROVEMENTS IN APPARATUS FOR SHEARING AND PUNCHING METAL PLATES AND
OTHER ARTICLES
"
My Invention relates to that class of apparatus for shearing and punching metal
plates and other materials or articles in which rotating disc cutters are employed
and my improvements therein consist as follows:-
According to one modification of apparatus constructed according to my Invention
I provide two discs or sheaves made of or faced with tempered steel to maintain
a keen edge and I bevel or hollow them out on their circumferences so as to obtain
a clean cut. These discs or sheaves are secured by nuts to their spindles or shafts
so as to render them capable of being readily adjusted or removed for the purpose
of sharpening or of being replaced by others. The cutter shafts are arranged
parallel to each other in a frame in such a manner that the faces of the sheaves
slightly overlap each other and are geared together so that the sheaves may revolve
in opposite directions with the same circumferential velocity. One of the cutter
shafts or spindles receives a rotary motion by means of a worm wheel and worm
worked by a crank handle or pulley or by any other suitable arrangement.
The metal plate or article to be sheared is fed in between the sheaves the
overlapping edges of which shear it by a continuous motion which is applicable to
curved corrugated or flat surfaces and the line of division may be made to take any
required direction by presenting the plate at the requisite angle or angles. If a
slot be made in any part of a plate away from the edge sufficient to admit the'
overlapping edges of the sheaves a hole of almost any shape and size may be cut
but.
Or
In combination with the sheaves and carried in the same frame I arrange a
punch to be actuated from one of the cutter spindles upon which I fix an eccentric
n such a manner as to cause the punch to act once for each revolution of the said
shaft a guide and die plate being provided to ensure its proper working.
nstead of a simple eccentric or cam a compound cam or eccentric may be employed
which will cause the punch to act two or more times for each revolution of the shaft.
If the compound eccentric or cam be required to make three strokes of the puncli for

page_text: example to one revolution of the shaft its revolving surface must be provided with
three similar and equidistant projections.
'
This compound eccentric is formed with or placed between two revolving dises
in each of which is provided a recess or track the contour of which corresponds in
form to the surface of the compound cam or eccentric. In these tracks or recesses
work the ends of a cross head with which the punch is provided so that the punch
which is restricted to a vertical motion only is caused thereby to ascend after each
descent caused by convex portions of the cam or eccentric. In order to regulate the
downward throw or travel of the punch I form a recess in the cross head or top of
the punch for the reception of a separate piece of metal against which the cam as
it rotates will act and thereby cause the punch to descend more or less according to
the thickness of the piece inserted. The recess in the top of the punch should be
of sufficient depth to admit of the rotation of the cam without operating the punch
when no intervening piece is inserted in the recess.
If desired two or more punches may be worked from the shaft of the revolving
disc in the manner described but according to another modification of apparatus
constructed according to my invention for working several punches. I provide a
spindle or shaft at right angles to the cutter shaft actuated by means of a worm
and worm wheel or by other equivalent contrivances from any suitable prime mover.
The number of punches worked from this shaft will be determined by the length
thereof and the size of the apparatus. The position of the punches on the shaft
may be varied so as to punch holes only of a certain pitch or to suit different
pitches of holes I provide the eccentric of each punch with a stud and the shaft
upon. which they are mounted with a slot or with a series of holes to suit the studs
so that the eccentrics working the punches may be secured in different positions
and I provide corresponding guides and die plates which can be placed in position
and withdrawn as required. Punches worked by compound cams or eccentrics
are applicable to this modification as well as to the modifications hereinbefore
described.
.
When the spindles which carry the sheaves are arranged in the frame in parallel
positions the edge of the plate will be cut to a plane at right angles to the surface
of the said plate but in order to give the edge of the plates a bevel (such for
example as required for caulking plates intended for boilers) I arrange one of the
sheaves at an inclination to the other the preferable arrangement being for the
lower spindle to remain horizontal and the upper spindle to be inclined to it in
which case the cutting edge of the lower sheave must be bevelled to suit the angle
of the face of the upper one.
When the amount of bevel required on the edge of the plate is only small the
inclination of the spindles to each other will be correspondingly slight and the
spindles can be geared to each other in the same way as when both are parallel
but if the inclination of the spindles is considerable the construction of the machine
may be modified by providing a separate spindle fitted with two bevel wheels
so arranged that one of the said bevel wheels will gear with a bevel wheel on one
of the sheave spindles and the other bevel wheel with a bevel wheel on the other
sheave spindle. For the purpose of cutting a metal plate or other article into
strips I provide several pairs of sheaves secured to separate spindles arranged at the
desired distance apart in the frame and driven by worms and worm wheels or
other equivalent contrivance the same as when there is only one pair of sheaves all
the worms however being carried on one shaft so that the action of the several
pairs of sheaves shall be uniform and coincident. The sheave spindles may be so,
arranged in the frame that the machine will cut a plate into a number of strips of
a certain same width only or the cutter spindles may be adjustable so that the
position of the sheaves may be varied in order to divide the plate into strips of
different widths if required. Machines constructed to cut bevel edges or to cut
plates into strips are by preference provided with one or more punches in combina-
tion therewith as before described. In all cases where the metal plates or other
articles to be sheared are either flat or curved the discs or sheaves are by preference.

page_text: circular but for cutting articles having deep corrugations the discs or sheaves are
by preference of an elleptical form.
In the modifications herein before described the spindles of each pair of cutting
dises have been described as being geared together the object of this is to ensure a
better grip of the article to be cut by the edges of the sheaves but in cases of thin
metal plates or articles easily sheared it will be sufficient if a direct rotary motion
be imparted to only one of the sheave spindles as the other will be compelled by
friction to revolve at the same circumferential velocity and with the same shearing
effect. In some cases such for example in cutting curved or circular holes or small
concave curves or recesses in metal and other plates the discs of each pair may be
of different diameters but must be driven with the same circumferential velocity.
In cases where very thick plates are to be cut the rotary motion imparted to the
cutter spindles may not provide sufficient grip to cause the plates to pass through
the shearing edges of the sheaves in this case I provide a travelling bed to which I
fix the plate and impart to it a motion equal to the circumferential velocity of the
sheaves the motion of the bed being obtained by a rack and pinion worked from
the driving shaft of the cutting sheaves or by any other suitable means. In order
to cut metal plates to a concave edge or internal curve I mount the cutting
apparatus on a platform fitted to revolve about a centre so that the sheaves will
cut the plate (which is held in a stationary position) to the required radius.
This frame or platform may be supported on wheels like a turn table and may
be caused to revolve by a rack and pinion or other suitable means,
For the purpose of rendering this apparatus capable of cutting curves of different
radii the frame carrying the shearing discs or sheaves is adjustably mounted upon
the platform and may be moved nearer to or further from the fulcrum or centre by
means of a screw in a similar manner to a lathe head or otherwise.
The cutting discs may be actuated by the motion of the platform by providing
beneath the platform a shaft or spindle arranged to turn in bearings with its axis
pointing towards the pivot or fulcrum and carrying a pinion in gear with a
stationary crown wheel fixed concentrically upon the socket of the pivot.
Upon motion being imparted to the platform the pinion will be caused to travel
over the crown wheel and thereby receive a rotatory motion which may be trans-
mitted to the shaft of the cutting disc through an endless band passed round a
drum fast on the shaft and a similar drum on the shaft of the cutting disc.
In order to compensate for the wear of the sheaves and the consequent reduction
of their diameter by resharpening the distance between their centres should be
adjustable this may be provided for in various ways for example the frame carrying
the sheaves may be made in two parts one part to carry the upper sheave spindle
and bolted or otherwise secured to the other part carrying the lower sheave with
the necessary thickness of packing between the two parts or one or both of the
cutter spindles may be fitted in eccentric bearings in the frames so as to be capable
of being raised or lowered within certain limits as required. The same object may
be effected by set screws or other equivalent means so as to adjust the sheaves to
obtain a suitable over-lap. For cutting an internal or concave curve the upper
sheave should project beyond the lower one but in other cases it is more convenient
for the lower sheave to project beyond the upper one. The tendency of a portion
of the metal plate or other article passing through the sheaves in the process of
shearing is to turn downward in the form of a curve to prevent which a guide may
be placed in a suitable position to receive this portion of the plate or other article
which will be again straightened if passed under a roller.or pulley above the guide
and pressed down by a weight or spring.