Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates generally to shearing appara~us,
and pertains more particularly to a shear mechanism for cutting
metal bars and strips.
Shear mechanisms, of course, are not new, as various
types of shear mechanisms have been devised in the past. A
number of such mechanisms have involved heavy and cumbersome
cast iron frames having massive ~aw members on which are mounted
the shear blades. It will be appreciated that substantial re-
active forces can be involved when shearing various types of
metal bars and strips, thereby necessitating reIakively bulky
equipment. The size of such shear mechanisms has contributed
greatly to their cost. Cost reduction efforts have resulted in
somewhat inferior shear mechanisms, particularly when attempts
are made to produce a reIatively lightweight and portabIe shear
mechanism. Inasmuch as small job shops cannot afford the
capital investment required for the purchase of massive equipment,
such shbps have been compelled to either send out the work to
be cut to a larger plant or resort to time-consuming sawing
:
~ operations. Therefore, a real need has existed for lightweight
.,
and portable shearing apparatus.
My Uniked Stakes patent No. 3,899g950, issued on
August 19, 1975, for "BAR SHEAR" has proved to be highIy success-
ful. Even though my patented shear has performed admirabIy, it
- still requires a number of moving parts and its cost, while less
khan most comparable prior art devices, has presented a challenge
to provide a shear mechanism that will be even less expensive.
Cost reduction and simplicity go virtually hand in hand, and
while my patented mechanism has been less costly to produce,
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owing to its comparative simplicity, it still has left some-
thing to be desired as far as the ultimate in simplicity and
low cost.
Accordingly, one ob~ect of the present invention
is ko provide an exceedingly inexpensive shear mechanism
which is simple and lightweight.
Another ob~ect of the invention is to provide a
shear mechanism lending itself readily to being constructed
in a manner such that it is portable and can be readily moved
~rom place to place within a given shop or easily transported
to job sites a~ay from the shop.
Another obj~ect is to provide a shear mechanism that
will shoulder relativeIy large shearing forces and at the same
time be compact and lightweight.
A further ob~ect of the invention is to provide an
exceptionally rugged shear mechanism that is virtually main-
tenance-~ree.
Briefly, my invention comprises two upstanding fixed
; plates having a movabIe ~plate sandwiched therebetween. The
several plates each have a notch extending inwardly from one
edge, one fixed plate having a detachable shear bIade associated
with its notch and the movabIe plate having a cooperable shear
blade associated with its notch. The two ~ixed plates each
have two circular holes in which are received pins that pivotally
mount two pair o~ actuating arms. The movabIe plate also has
formed therein two cireular holes and additional pins are re-
ceived in the two last-mentioned holes. An actuator, such as an
air cylinder, ~orces the arms into different angular positions to
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cause the movable plate to be displaced with respect to the
fixed plates in the performance of a shearing operation. Appro-
priately located slots in the fixed plates and appropriately
located slots in the movabIe'plate permit the movabIe plate to
move sufficiently in effecting the she'aring operation.
In the drawings:
Figure 1 is a side eIevational view of a shear
mechanism exemplifying my invention;
Figure'2 is a front elevational view taken from the
right in Figure l;
Figures 3, 4, 5 and 6 are sectional details taken in
the direction of lines 3-3, 4-4, 5-5 and 6-6 o~ Figure 1 for
the purpose o~ clearly showing the various circular hbles and
elongated slots formed in the several plates;
~ igure 7 is a view, partly in section, taken in the
direction of line 7-7 of Figure 2, and
Figure 8 is an exploded perspective view of the
basic parts comprising my shear mechanism, the spaced relation
~urther facilitating an understanding of the manner in which
the 'illustrated mechanism is constructed.
The shear mechanism selected for the purpose of
illustrating my invention has been denoted generally by the
re~erence numeral 10. It includes a base plate 12 having a
pair of angle irons 14, 16 (best viewed in Figure 8) provided
with holes 18 in their horizontal flanges and holes 19 in
their vertical flanges, the holes 18 accommodating bolts 20
that hold the angle irons 14,- 16 in place on the base plate 12.
At this time attention is called to two side plates
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22, 24 each hàving a bottom edge 26, a top edge 28, a ~orward
edge 30 and a rear edge 32. Near the bottom edge 26 o~ each
plate 22, 24 is a pair of holes 34, and near the top edge 28
of each plate 22, 24 -l`S a pair of hbles 36. Bolts 38 extend
through the holes 34 and the holes 19 in the angle irons 14,
16 so as to fixedly support the side plates 22 and 24 in that
the angle irons are held in place by the previously mentioned
. bolts 20. Additional bolts 40 .extend through the top holes
36 in the plate:s 22, 24 and also through a pair o~ holes 42
. 10 in a spacer block 44. The spacer block 44 has a thickness
of the two vertical ~langes beIonging to the angle irons 14 ~
16, these vertical M anges having the holes 19 therein. Other
spacing means, such as sleeves having the proper length can
be substituted for the spacer block 44 that has been shbwn.
Notches 46 extend inwardly from the ~orward edge
30 of each ~ixed plate 22, 24. Attached to the fixed plate
22 is a shear blade 48, the plate 22 .being recessed or under-
cut at 50 for the accommodation o~ the bIade 48. The blade
48 is detachably ~astened by a plurality of bolts 52 which
20 extend into tapped holes provided in the plate 22 adjacent
its notch 46.
A pair o~ circular holes 54, 56 is formed in each
plate 22, 24. The hole 54 of each plate, as is evident from
Figure 8, is nearer the edges 26 and 30, the hole 56 of each
plate is nearer the edges 28 and 32. Also formed in the plates
22, 24 is a pair of elongated slots 58, 60. The slot 58 of
each plate, as can also be seen in Figure 8, is nearer the
edges 26 and 32, whereas the slot 60 Or each plate is nearer
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the edges 28 and 30. The~purpose or role played by the
apertures constituking the holes 54, 56 and the slots 58, 60
will be explained hereinafter.
Sandwiched between the two side or fixed plates 22,,,
24 is a movabIe plate 62 having a bottom edge 64, a top edge
66, a ~orward edge 68 and a rear edge 70. Tnasmuch'as the
plate 62 is to be moved up and down with respect to the fixed
plates 22,, 24, it will be appreciated that the combined thick-
ness of the vertical flanges of the angle irons 14, 16, these
being the flanges containing the holes 19 therein, is sufficient
to provide a slight amount of clearance be'tween the two plates
22,,, 24. Whereas the vertical flanges on the angle iron 14, 16
provide the proper spacing for the movable plate 62 adjacent
its bottom edge 64, the spacer block 44 provides the proper
clearance between the side plates 22, 24 adjacent the top edge
66 of the plate 62. In actual practice, vertical strips are
used as sp-acers, there being one adjacent the rear edges 32
of the plates 22, 24 and two adjacent the forward edges 30
(one above and one below the notches 46). The mo~able plate
62 has a notch'72 extending inwardly from its forward edge 68.
The notch'72 has a blade 74 associated th~rewith, the plate 62
being recessed or undercut at 76 so as to accommodate the blade
74. As with the blade 48, bolts 78 detachably fasten the blade
74 in place.
The movabIe plate 62 is formed with a pair of circular
holes 80,, 82 and a pair of eIongated slots 84, 86. The hole
80, as can be appreciated from Figure 7, is nearer the
edges 64 and 70, and the hole 82 is nearer the edges 66 and 68.
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Although not co~pletely understandable at :this stage :of the
description, it can be pointed out in passing that :the cir-
cular holes 80~ 82 have the same general spacing as slots
58 and 60 in the fixed plate:s 22, 24, and the slots 84, 86
have the same general spacing as the holes 54, 56 in the plates
22, 24. As with the slots: 58, 60 o~ the plates 22, 24 which
extend parallel to.the edges 30, the slots 84, 86 extend
parallel to the edges 68 of the plate 62.
' A headed pin 88 extends through the hole 54 in the
~' 10 plate 22, through'the 'slot 84 in the plate 62 and through the
hole 54 in the plate 26. Similarly, a headed pin 90 extends
through the circular hole 56 in the plate 22, the slot 86 in
the plate 62.and the hole 56 in the plate 24. Washers 92.are
locate:d between the heads of the pins 88 and the plate 22,
whereas additional washers 94 are disposed between cotter pins
' '96 and the plate 24. Still further, a headed pin 98 extends
.
through'the slot 58 in the plate 22, through the circular hble
80 in the plate: 62 .and, through the slot 58 in the plate 24.
Another headed pin 100 extends through'the slot 60 in the plate
22, through the'circular hble'82.ln the plate 62 and through
the slot 60.in the plate 24.. Washers 102 confront the plate :22.
and washers 104 confront the plate 24 as far as the pins 98 and
100 are concerned, there being cotter pins 106 passing through
the ends of the pins 98~ lOO.adjacent the washers 104..
Two lo~er arms 108, 11~ (one at one side of the shear
mechanism 10 and one at the other side) ha~e holes 112 and 114
(Figures3 and 5, respecti:vely) near one end thereof and a hole
116 at the other end. Two upper arms 118~ 120 (hereagain one
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at one side of the mechanism lO.and one at the other side~ have
holes 122, 121~ (Figures 4 and 6, respectively) corresponding to
the holes 112.and 114 in the arms 108, 110 and a single hole
126 at the far end. As with the hole 116 in the arm 110, the
~ hole 126 in the' arm 120 cannot be see'n.
: As already mentioned, the pin 88 extends through'the
hole 54 in the fixed plate 22, through the slot 84 in the
movable plate 62 and also through the circular hole 54 in the
plate 24. Similarly, as also earlier stated, the pin 90 extends
through the circular hole 56 in the fixed plate: 22, through the
slot 86 in the movable plate 62 and through the circular hole
56 in the other fixed plate 24. Since the side plates: 22., 24
~ are fixed, it follows that the pin 88 provides a ~ixed pivot
'. point or axis ~or the lower arms 108, 110, whereas the pin 90
provides a fixed pivot point :or axis for the upper arms 118, 120..
The pins 98, 100, on the other hand, support the
; movable plate 62.since the pin 98 extends through the slot 58
in the plate 22, through the circular hole 80 in the movable
plate 62'and through the slot 58 in the plate 22,. the circular
hble 80 provid~ng only a slight' clearance. By the same token,
the pin 100 extends through the slot 60 in the plate 22 and
through'the slot 60 in the plate 24, being recei:ved in the
circular hole 82'.of the movable plate 62 which here again pro-
vides only a slight clearance with the pin. It is important
to understand that the pins 98 and 100 provide the sole support
for the movable plate 62.
A fluid actuator denote:d generally by the reference
numeral 128 is employed for urging or spreading apart the ends
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of the arms 10~, 110 cont~ining the' holes 116 and the ends of
the arms 118, 120 containing the hbles: therei'n. More specifically,
the actuator 128 includes' a cylinder 130 containing a reciprocal
piston 132 having a piston rod 134. By means of tubes: or con-
duits 136, 138 air or liquid can be forced into and withdrawn
from the cylinder 130 in order to: move :the piston 132.vertically
therein. The closed end of the cylinder 130, this being the
lower end, has a U-shaped member 140 affixed thereto, whereas
a U-shaped membe'r 142 is mounted at the free end of the piston
rod 134, the member 140.spanning or bridging thé distance between
the arms 108, 110 and the member 142 spanning the distance :
between the arms 118, 120. Thus, the U-shaped members 140,. 142
provide laterally spaced legs ~or the accommodation o~ a pin
144 as far as the lower U-shaped rnember 140.is concerned and
a pin 146 as far as the upper U-shaped member 142 is concerned.
Having presented the foregoing information, the
manner in which my shear mechanism 10 operate~s should be easily
understood. Nonetheless, a brief operational description, it
is beIieved, will be of assistance in appreciating the full
benefits to be derived from a practicing of my lnvention. With
the piston rod 134 retracte~d as shown in ~igure 1, this results
in the notch 72 of the movabIe plate 62 being in registry with
the notches 46 of the fixed plates 22, 24. The shear mechanism
lO.is thus in readiness for having the stock, such as a bar or
strip (nottshown), inserted into the' aligned notches 46 and 72..
When the fluid under pressure :is introduced into the
lower end of the cylinder 130.via the .tube 136~ the piston 132
is forced upwardly with the consequence that its piston rod 134,
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through the U-shaped member 142 attache'd to its upper end, acts
against the upper pair of actuating arms 118, 120. Concomitantly,
the cylinder 130 is reactiveIy urged downwardly so that the lower
arms 108, llO are forced downwardly through'the U-shaped member
14~,
In other words, the pins 144, 146 are urged farther
apart wikh th~e consequence that the angulation of the arms
108~ llO with~'respect to the ~arms 118, 120 is changed. More
specifically, the 'lower arms 108, 110 are rocked or rotated in
a counterclockwise direction about the ~ixed axis provided by
the 'pin 88, whereas the upper arms 118~ 120 are rocked or ro-
tated in a clockwise direction about the' ~ixed axis provided
by the pin 90.
Since the pin 98 passes through the lower arms 108,
112 and is thus carried thereby, it moves' downwardly when the
lowe'r arms 108, llO- are ~rotated in a counterclockwise 'direction
about the ~axis provided by the 'pin 88. Of course, the slots 58
in the'~ixed plates 22, 2~l permit the pin 98 to move withbut
inter~erence. Also, inasmuch'as the pin 9~ passes' through'the
circular hble ~80 in the movable 'plate 62, the plate 62 is urged
downwardly. By the same token, the upper arms 118, 120 are
rotaked in a clockwise 'directlon about the axis provided by the
pin 90 to cause the' pin 100 to move 'downwardly. Because the
pin 100 passes through'the circular hole 76 in the movabIe 'plate
62, it, too, moves downwardly to lower the` movabIe plate 62 ~ust
as the pin 98 is doing.
With the plate 62 moving downwardly, it ~ollows that
its notch 72 which is initially in registry with the notches 46
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moves out of registry. Stated somewhat :differently, th:e bIade
74, being attached to the plate: 62, is.moved downwardly
reIative to the bIade 48, which is attached to the plate 22,.
to effect the shearing o~ the stock, whether it be a rod, strip,'
or other work to be sheared, that was inserted in the notches
46, 72 wh~en they were in registr~. ~
It :should be recognized that the actuator 128 does
not exert a reactive force against any fixed member such'as
the base plate 12. In the prior art, the :reactive force 'of
the actuator had to be abs'orbed by a ~ixed member. This
accounts for the massivenes's of many of the prior art shear
mechanisms.
It should also be recognize'd that the slots 58 and
60 .in both of the plates 22., 24., as well as the slots. 84, 86
in the.plate'62, are :of ample 'size.:so th:at the 'shearing opera-
ti:on is complet'e:d wel.l before any of the pins 88, 90,. 98.or
lOn.hear against ~the ends of thes:e slots~. During the actual
shearing, the're are reactive force's, but it should be appreciated
that these :rorces: are directed into the plates 22, 24 and 62.
in such a way as to subject the ~plates 22, 24 to tension forces
and the plate::62'to compressive :rorces. Howe:ver, these:forces
are transmitted longitudinally within the plates and can readily
be accommodate:d without having to make 'the plates unduly thick.
As a matter of fact, the thickness of the plate:s 22 and 62 is
influenced largeIy by the thicknes~s of the bIades 48 and 74.
Since the plate: 2LI does not activeIy participate in the shearing
function, it can be :thinner than either of the other two plates
22 and 62. The sandwiching of the three:plates 22, 24 and 62
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together for all practical purposes precludes any plate
buckling. More specifically, since the movabIe 'plate 62 is
placed under compres'sion, the side or fixed plates 22, 24 reslsk
any tendency for the central or movable plate 62 to bend.
Depending upon the thickness or thinness of the plate 62, there
can be some bowing but this is only to the'exten~ permitte~d by
the 'clearance bet'ween the fixed plates 22, 24. The thickness
of the vertical flanges on the 'angle 'irons 14, 16, as already
explained, controls the clearance 'at the lower edge 64 of the
10 movable plate and the spacer bIock 44 the clearance at the upper
edge 66 of the movable plate,' these 'eIements in turn determining
the clearance throughout thb length'or height of the plate 62
wi'th'respect to the plates 22, 24.
Owing to the unique manner in which the actuation of
the movabIe plate 62 is achieved, a consi~erable size reduction
can be effected as far as the 'overall dimensions of the various
components comprising my shear mechanism lO. Hence~ my mechanism
can be moved quite readily from place to place. In addition,
only a few simple parts are needed in fabricating a shear
mechanism of the character' ~ust described, thereb'y enabling it
to be made'and sold at a lower cost than other equipment capabIe
of shearing the same size stock. The simplicity also virtually
assures a long and trouble-free 'useful life.
In order to simpli~y the drawings, the bearings for
~he various pins 88, 90, 98, 100, 144 and 146 have not been
shown. These bearings are preferabIy needle bearings, but can
be sleeve bearings such'as thbse illustrated in my hereinbefore
mentioned Patent No. 3,899,950.
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