IMPROVEMENTS IN MACHINES FOR CUTTING SHEET METAL TO BE USED IN THE MANUFACTURE OF CANS OR CASES
Year: 1884

page_text: COMPLETE SPECIFICATION.
I WILLIAM ROBERT LAKE of the firin of Haseltine Lake & Co Patent Agents
Southampton Buildings in the County of Middlesex do hereby declare the nature
of my Invention for "IMPROVEMENTS IN MACHINES FOR CUTTING SHEET METAL
TO BE USED IN THE MANUFACTURE OF CANS OR CASES" and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
This Invention relates to machines for cutting blanks for sheet-metal cans or
cases wherein rotary cutters are employed. In this class of machines considerable
difficulty has been experienced in their practical operation, owing to the tendency
of the stock to buckle between the cutters, or bend out of a true plane either from
the action of the cutters on the sheet or by reason of previous buckles, dents or
inequalities in the sheet when it is fed to the machine before entering the cutters.
This buckling of the stock causes the can-body to vary in width at different points,
to the extent of sometimes from one thirty-second up to one sixteenth of an inch,
which of course occasions great difficulty and irregularity in the manufacture of the
cans and often causes them to be imperfect and leaky. Another trouble in the
operation of these machines, which it is also the object of my Invention to
overcome, is the tendency of the sheet to drag harder or draw faster on one side
than the other, and thus pass slightly askew instead of squarely through the
cutters. These results I accomplish by combining with the cutters a series of
spring-bridges, supports or guides above and below the sheet, and which extend
through the machine and under and between the cutters, so as to support and hold
the sheet flat directly at the point or line where the cutting is being done as well
as on each side. thereof, and thus render it impossible for the sheet to buckle
between the cutters. The bridges or guides are secured by bolts or otherwise to
slotted rails or bars attached to the standards of the machine. These bridges not
only serve to prevent the sheet from. buckling. under the action of the cutters as
they support it at the very point where the cutting is done, but they also serve to
D

page_text: smooth and flatten out the sheet as it passes under the cutters, to strip the slitted
blanks from between the cutters as they issue therefrom and prevent their being
turned or carried up or down with the revolving cutters, and also to equalize the
drag or draw upon both sides of the sheet and thus cause it to pass squarely
through the machine. To aid in the accomplishment of the latter end, I also
provide the feed-table with a side guide to abut against the side of the sheet. The
stripping of the slitted blanks from between the contiguous cutters on the upper or
lower shaft tends very much to equalize the draught on both sides of the sheet and
to cause it to pass freely and squarely through the machine, because if one of the
blanks happens to be carried up by the revolving cutters it causes an unequal
resistance at that point, as well as a tendency of the sheet to buckle.
In the accompanying Drawings which form a part of this Specification, and in
which similar letters of reference indicate like parts.
Figure 1 is a rear elevation of a machine embodying my Invention.
Figure 2 is a side elevation of the same.
Figure 3 is a detail side view of the bridges, and Figure 4 is a detail end view
of one of the bridges.
In said Drawing A represents the frame of the machine. B B' the shafts to
which the upper and lower revolving-cutters C and C are secured, and' D D' are
the standards in which the boxes d d of said shafts are supported. The lower
box d is stationary, while the upper one d' is adjustable by means of the set
screws d² and d³, so that the shaft and cutters thereon may be adjusted closer or
farther apart as may be required.
E is the feed-table upon which the sheets are supported as they are fed through
the machine. This table is provided with a guide e on one side by which the sheet
may be guided so as to pass squarely through the machine. F is a table or
support at the rear of the inachine for receiving the slitted blanks as they come
from the rotary cutters C C¹. This table is supported on an arm f secured to the
frame of the machine, and it may be adjusted to or from the machine by means of
the set-screw f. G and G¹ are a pair of slotted bars secured to the standards D D¹
by means of bolts g at the rear of the machine, and K K and K' K¹, are the upper
and lower spring bridges or guides which extend through the machine and under
and between the cutters C C and C¹ C'. These bridges K and K¹ aro secured in
the slots of the bars G and G¹ by means of bolts which pass through slots k³
in the bridges K and K'. It will be observed that the opposing contiguous cutters,
whether on the upper or the lower shaft, fit either both inside or both outside each
other. Between the contiguous cutters C, which fit outside the opposing cutters C³,
I place three bridges KKK, the two extreme bridges fitting directly over the
opposing cutters C¹ C', which fit inside the cutters C, C; and between said
cutters C¹ C¹ fitting inside, I place two bridges K' K. The bridges K K' extend
entirely through the machine between the cutters, and the ends of the same are
slightly curved, as shown at k³, so as to readily receive the sheet between them.
As the bridges K K' extend entirely through between the cutters, the sheet is
supported at the very point where the cutting is being done, so that the action of
the cutters has no tendency to pucker or buckle the sheet.
L represents the driving pulley, and the spur-gears for driving one shaft
from the other. By means of the slots in the bridges K and K', the same may
be adjusted vertically up or down as may be required. The number of bridges
between each pair of cutters, may of course be increased or diminished without
materially affecting the operation of my improvement. If the bridges are made
wider, a fewer number may be employed than when made narrow, and if preferred,
a single wide bridge extending the whole width between the contiguous cutters
on either shaft may be employed instead of two or more, as shown.
I am aware that heretofore in these rotary cutting machines, guide or feed
rollers have been employed, located immediately in front of the cutters; but these
guide rollers of course could not extend under the cutters so as to support and
guide the sheet at the point where the cutting is being done, so that the sheet was

page_text: still liable to buckle under the action of the cutters. Nor did these guide rollers
perform the function of stripping the slitted blanks from between the contiguous
cutters which fit outside their opposing cutters.
By means of the feed-table, the upper and lower spring bridges, and the receiving
table, the sheet is supported and held in the same plane while passing through the
machine, and all tendency of the sheet to buckle or to pass through the machine
askew is overcome.
The receiving-table F is provided with guides F' one on each side thereof, to
guide and direct the slitted sheet as it comes from the cutters. These guides F'
are adjustable, being secured to the slotted-bars G G₁ by means of bolts which
pass through the slots in said bars. The guides F¹ extend back to the cutters.
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 sheet-metal slitting machine, the combination of the upper and lower
rotary cutters, with bridges or guides extending under and between the cutters, 80
as to support the sheet at the point where the cutting is being done, substantially
as specified.
2 The combination of the upper and lower rotary cutters, with bridges
extending through the machine, under and between the cutters so as to support the
sheet at the point where the cutting is being dono, and strip the slitted blanks
from the cutters as they issue therefrom, and a feed-table provided with a guide on
one side, substantially as specified.
3rd The combination of the upper and lower rotary cutters, with bridges
extending through the machine, under and between the cutters, a feed-table
provided with a guide on its side, and a receiving table whereby the sheets are
held and supported in the same plane while passing through the machine,
substantially as specified.
4th The combination of the upper and lower rotary cutters with spring-bridges
extending through the machine under and between the cutters, substantially as
specified.
5th The combination of the upper and lower rotary cutters, of the slotted-
bars GG, and bridges K K' secured to said slotted bars, and extending through
the machine under and between the cutters, substantially as specified.
Dated this 10th day of June 1884.
HASELTINE, LAKE & Co.,
For the Applicant.