IMPROVEMENTS APPLICABLE TO SCREW STOCKS
Year: 1878

page_text: LETTERS PATENT to Percival Everitt, of Great Ryburgh, in the County of
Norfolk, Engineer, for the Invention of "IMPROVEMENTS APPLICABLE TO
SCREW STOCKS."
Sealed the 23rd May 1879, and dated the 29th November 1878.
PROVISIONAL SPECIFICATION left by the said Percival Everitt at the Office
of the Commissioners of Patents on the 29th November 1878.
PERCIVAL EVERITT, of Great Ryburgh, in the County of Norfolk, Engineer.
"IMPROVEMENTS APPLICABLE TO SCREW STOCKS."
This Invention relates to the adaptation to screw stocks of the ordinary
construction of the feeding and gripping cam for which I obtained Letters Patent,
bearing date February 5th, 1878, No. 470.
In the Specification of this Patent I described the feeding and gripping cam (by
which the moving die is propelled) as mounted on the stock, and actuated by a
lever fitted to the side of the stock; I now propose to mount the cam in a block
which fits into the rectangular slot of the screw stock, and is flanged on one side to
give it a lateral bearing against the screw stock, while a flange on the cam proper
engages with the moveable die and retains the block in position.
The lever for working the cam is fitted to the hub of the cam, which is free to
turn in bearings in the block; the moving die being brought into contact with the
cam receives the feed motion therefrom through the action of the lever, and by
iudicating.on the screw stock the space through which the lever is to be moved the
amount of feed may be determined with accuracy.
It should be remarked that the cam instead of having its bearings in a block
fitting into the slot of the screw stock may be mounted in plates, which will clip
the sides of the stock, such plates being held together by transverse screws
or rivets.
An obvious modification of the Invention is to mount the cam in the cutting die
and cause it to bear against the stock, thus doing away with the block altogether.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Percival Everitt in the Great Seal Patent Office on the 29th May
1879.
PERCIVAL EVERITT, of Great Ryburgh, in the County of Norfolk, Engineer.
"IMPROVEMENTS APPLICABLE TO SCREW STOCKS."
This Invention relates to the adaptation to screw stocks of the ordinary
construction of the feeding and gripping cam for which I obtained Letters Patent,
bearing date February fifth, One thousand eight hundred and seventy eight,
No. 470.
In the Specification of this Patent I described the feeding and gripping cam by
(which the moving die is propelled) as mounted on the side of a double handled
stock, and actuated by a lever fitted thereto.
I now propose to mount the can within the rectangular slot of the screw stock
instead of upon the stock, so that the strain of the cam when acting will be taken
by the stock instead of by a pivot pin, as in the arrangement above referred to.
My Invention admits of several slight modifications without departing from the
principle above enunciated.
In Sheet I. of the accompanying Drawings Fig. 1 shews in side or plan view a
screw stock fitted with a feeding and gripping cam arranged according to this
Invention; Fig. 2 is a longitudinal section of the same; and Fig. 3 is a transverse
section taken in the line 1, 2, of Fig. 1.
In this arrangement A is the feeding and gripping cam formed with a hub,
which has its bearings in a block B fitting into the rectangular slot of the screw
stock C; this block B is flanged on one side to give it a lateral bearing against the
screw stock.
D is the lever for working the cam; this lever is fitted to the hub of the cam,
and is secured in place by a nut; E is the stationary die; and F the moveable die,
the same being held in place by V guides on the opposite sides of the rectangular
slot of the screw stock.
The moving die F being in contact with the cam A will receive its feed motion
therefrom through the action of the lever D, and by indicating on the screw stock
the space through which the lever is to be moved the amount of feed may be
determined with accuracy.
In order to retain the cam in the screw stock it is formed with a concentric
flange a, which enters a segment shaped rebate formed on the back of the die F.
The radius of this flange coincides with the largest radius of the cam, and by
bringing this portion of the cam round into line with the dies when there is no
work between the dies there will be no interlocking of the flange with the die F,
and consequently the block with its cam may be removed from the screw stock.
In Sheet II. I have shewn a modification in which the cam A is carried by a
pair of plates B, B', instead of the block. The larger plate B clips the screw stock,
and the smaller plate B¹ fits snugly into the rectangular recess of the stock.
.
Fig. 4 is a plan or side view of a screw stock fitted with this modified form of
my Invention.
Fig. 5 is a longitudinal section of the same; and Fig. 6 is a transverse section
taken in the line 3, 4, of Fig. 4. The plates B, B', which form bearings for the
hub of the cam A are secured together by transverse pins, and the cam, which
in this case is made somewhat narrower than the screw stock, enters a segment
shaped recess cut transversely in the back of the moving die F.. The interlocking
of the cam with this die will prevent the displacement of the cam when the stock
is in use without interfering with its removal from the stock when it is required to
shift the dies.
The plates B, B¹; are formed with collars on their inner faces to provide an
increased width of bearing surface for the hub of the cam.

page_text: This hub is extended beyond the larger plate B to receive the hand lever D and
a nut for retaining the same in position.
In Sheet III. I have shewn a further modification of my Invention, in which
both the block and bearing plates are done away with, the cam being caused to
interlock with the screw stock, and thus retain its working position.
Fig. 7 is a plan or side view of this modified form of screw stock; and Fig. 8 is
an edge view of the same; Fig. 9 shews the screw stock with the cam removed;
and Figures 10 and 11 shew the cam detached in side and plan views.
An annular recess a is turned in the perimeter of the cam A at the middle of its
length to receive the segment shaped rib c of the stock C. The hand lever D is
fitted to the hub of the cam as before, and the bearing for the cam in this
arrangement is the segment shaped rib c of the stock.
E is the stationary die; and F the moveable die, on the back of which the cam A
bears for pressing that die up to its work.
To remove or change the dies it is only necessary to move the cam forward clear
of the rib c; the cam is then free to drop out of the stock, and the dies may be
readily withdrawn and replaced by others.
This arrangement, it will be seen, is more simple than those shewn in Sheets I.
and II., and also posseses the special merit of those arrangements, namely, that of
throwing the strain directly upon the screw stock.
I prefer in general to employ this last described form of the Invention.
Having now set forth the nature of my Invention of "Improvements Applicable
to Screw Stocks," and explained the manner of carrying the same into effect,
wish it to be understood that under the above in part recited Letters Patent
claim,―
Mounting the gripping and feeding cam within the slot of the screw stock, as and
for the purpose above described.
In witness whereof, I, the said Percival Everitt, have hereunto set my hand
and seal, the Twenty seventh day of May, in the year of our Lord One
thousand eight hundred and seventy nine.
wזת
ATTTATתת
PERCIVAL EVERITT. (L.S.)