вход по аккаунту


Патент USA US2105402

код для вставки
Jan. 11, 1938.
Filed Aug. 2, 1935
2 Sheets-Sheet l
JáIL 11, 1938.
R. |_. BRowNLEE
Filed Aug. 2, 1955
2 Sheets-Sheet 2
L@ Ö
Z6 Y
Patented Jan. ll, 1938
Robert Leslie Brownlee, Chicago, Ill., assignor to
Dreis ¿£5 Krump Mfg.- Company, Chicago, Ill.
[application August 2, 1935, Serial No. 34,479
(Cl. 164-51)
' 7 Claims.
r1’his invention relates to squaring shears and
ïthe like, and more particularly to hydraulic hold
down devices therefor, and my main object is to
provide a hold-down apparatus in which a set of
5 self-contained units is employed, each unit hav
«ing an independent hold-down mechanism.
A further object of the invention is to arrange
the hold-down units in a simple series and not
dependent on any master or basic hydraulic ele
l0 ment for power.
Another object of the invention is to design
the hold-down units with means for self main
tenance in a highly efficient condition at all
' 15 ' An additional object of the invention is to pro
vide means whereby a defect in or injury to any
> of the hold-down units does not disable the bal
ance of the units or the machine for the purpose
of holding down the material, An important ob
20 ject of the invention is to so design the hold-down
- units that they will have an advantageous lever
age for the purpose of their function.
With-the above objects in view, and `any others
which may suggest themselves from the descrip
Y25 ‘tion to follow, a better understanding oi the in
vention may be had by reference to the drawings,
in which-_
Figure 1 is a front View of a portion of a squar
ing shear, showing the position of the novel hold
30 down apparatus;
Figure 2 is a section on the line 2-2 of Fig, l;
Figure 3 is va cross section onan enlarged scale
’Y 35
in use despite possible damage to or disability in
one or more of the hold-down units.
In carrying out the invention, speciñc refer
ence to the drawings indicates a typical squaring
shear at Iû, its ram at II, its bed at I2, and itsÁ ¿5
sides at Iûa. As shears of this type are standard,
the connections ior the operation of the ram
have merely been shown in part and need not be
described. For the purpose oi the hold-down
mechanism, a power shaft I3 running crosswise` 1g
of the machine is employed, the same having a
series of substantially semi-circular cams I3a at
points suitably spaced to induce the operation of
a set of hold-down plungers I4.
Each plunger I4 is mounted in an independent „ 1:,
unit represented by a block I5 of substantially
square form, the series of blocks being bolted as
indicated at I6 between a pair of frame plates I'I
carried by the sides lila oi the machine.
Each cam I3a is adapted to bear upon a rolleriÁ i
i8 carried by a cross lever I9 whose rear end is
pivotally supported at |90. by a hanger 20. The
frontal portion of each lever I9 pivotally receives
at |91) a depending pin 2| which has a thread at
its upper portion to receive a nut 22 with a nutl u,
lock 23 above it and `a free washer 24 below it. “
The balance oi the pin below the washer 24 is
taken up by an expansive spring 25. The latter
is adapted to bear upon a long bar 26 extending
freely between the two frame plates Il. The` 4,
bar 2S rests on the head portions 21a of a series u
of primary plungers 21.
of one of the hold-down units at the inception of
Each plunger 21 is fitted with a leather or other
packing 28 at its lower end, as clearly shown in
its operation;
Fig. 3, to make a snug ñt in a vertical circular _,
Figure 4 is a View similar to Fig. 3, showing the
bore I5a in the upper portion of the block I5.
unit at the termination ci its operation; _and
Figures 5, 6 and 'l are, respectively, sections on
The lower end of the bore I5a opens on a circular
` the lines 5_5, 6-6 and 'l-'I of Figure 3.
In the development of hydraulic hold-down
`>‘i0 means for squaring shears, it is customary to
employ a master cylinder for the fluid and to pipe
the latter to a set of smaller cylinders in the hold
down Zone for the control of plungers above the
work to be held down. With an arrangement of
this kind it is necessary to employ valves and
other accessory means in order to properly con
trol the action, vand should any mishap occur in
one of the smaller cylinders, or something go
50 wrong with one oi the plungers, the entire mech
anism must be laid up for repairs and the shear
kept out of operation for some time. I have
therefore departed from the customary hydraulic
design for the particular purpose, and devised an
55 apparatus which operates efficiently and remains
bore I5b of larger diameter, which continues to
the bottom of the block, receiving a closure in
the form of a plate 29 secured to the block by .
screws 30.
Within the bore I5b is located the hold-down
plunger I4, whose head Ida is fitted with a suit
able packing Iib to snugly iit the wall of the
bore. Between the head of the plunger and the ,n Cal
plate 29 is disposed an expansive spring 3l.
The top of the block I5 is sunken at I5c to
provide an annular well, the inner wall oi the
latter being an upward extension I5d of the stock
of the block I5 which forms the wall of the bore -
15a. A cross duct I5e extends from the bottom
of the well I5c into communication with the bore
55a; also, a similar passage I5f extends outwardly
to a tube 32 which rises along side the extension
15d to a high point in the well I5c.
In the operation of the hold-down mechanism
its normalk positions may be considered as indi
cated in Figs. 2 and 3. It is seen in Fig. 2 that
the flat portion of each cam I 3a is now above
in case of disability or failure in one or more of
the hold-down elements. Also, the novel mecha
nism is designed for operation without atten
tion or repair to its hydraulic units, since the
liquid in these is a lubricant and is automatically 5
the related lever I9. The latter is thus at the
upper end of its operation and is preferably maintained at Working capacity.
maintained there by a spring 33 between its front
I claim:
end and the top of the machine I0. However,
1. A hold-down mechanism for shears com
when the shaft I3 is given a partial turn, the prising a series of identical units, each unit being
prominent portions of the cam profiles will bear in the nature of a block perforated with longitu
down on the rollers- I8 of the levers I9, causing dinally communicating bores of different diam 10
these to press down on the bar 26 through the eters, a plunger in the smaller bore, a second
agency of the pins ZI and the intermediate plunger in the larger bore and forming a hold
springs 24. The bar 26 in turn presses down the down element by >hydraulic action when a liquid
set of primary plungers 21 which transmit en
is interposed between the plungers, a single bar
ergy through the hydraulic medium in the block extending longitudinally-over the external ends
bore I5a to the related hold-down plungers All. of all of the 'smaller plungers, and means to
Owing to the greater area of the plunger heads» actuate the bar with the eifect of advancing all
I4a. the action of the primary plungers 2l' will of such smaller plungers simultaneously.
impart a correspondingly greater pressure tothe
plungers Ië, procuring a powerful hold-down
action on the work. As the stroke of the plunger
' Mis limited byv the thickness of the work, it is
the province of the top springs 25 to take up
excess motion in the pins 2|; and the springs
3I are, of course, provided to retract the hold
down plungers I@ the moment the pressure from
above has been released, such as by a further
or reverse partial turn of the mainshaft I3 to
restore the cams I3a to the normal position
shown, in which event the springs 25 and 33 pro
cure the lifting of the lever I9.
It is seen from the above description that the
master control of the hold-down mechanism is
mechanical and extends only to the bar 25.
' 2. The structure of claim l, and a pair of sta
tionary side bars receiving the series of units be
tween them, said longitudinally extending bar
being disposed between said side bars and guided
3. The structure of claim 1, said bores being 25
vertical, and means in the region of the upper
bore to replenish such of the liquid as may escape
from the action of the plunger therein.
4. The structure of claim l, said bores being
vertical, and means in the region of the upper> 30
bore to replenish such of the liquid as may escape
from the action of the plunger therein, such
means comprising-an upward extension of the
Wall of the upper bore and defining an annular
well above the extension, and the extension being;> 35
Beyond the latter the hydraulic units are in a~ transversely perforated to establish communi
series numbered or spaced as the need may dic
tate and independent from one another as to
action or eifect. Thus, inefficiency or failurein
40 any of therunits will not be Ytransmitted-to the
other units; and the removal of any defective
units for attention or repair leaves the other
cation between the lower portion of the well and
said upper bore.
5. The structure of claim 1, said bores being
vertical, and means in the region of the upper
bore to replenish such of the liquid as may 40
escape from the action of the plunger therein,
units fully able to continue their work, so that such means comprising an upward extension of
the machine need not be out of service >at any - the wall of the upper bore and defining an an
45 time.
nular well above the extension, 'the extensionî
The object of the well §50 in the top of each being formed with transverse perforaticns be- ’
block I5 is to assure the maintenance of the tween the lower portion of the well and said
proper amount of hydraulic liquid in the plunger upper bore, and a vent tube directed from one
bore I5a. Thus, what liquid may work past the of the perforations upwardly to terminate above
50 plunger packing 28 will accumulate above the the extension.
same and eventually flow over the exterior Idd
6. A hold down mechanism yfor shears com 50
into the Well I 5c. The latter already has a spare prising a series of Work clamping elements, a '
supply of the liquid, as indicated in Figs. 3 and 4, separate and self contained hydraulic operating
which replenishes the supply in lthe bore I5 by unit for each element, each unit comprising a
En Ul
way of the .passage I5e. In this connection, the large cylinder and a small cylinder communicat-¿,v
tube 32 serves as anr airvent and relieves such ing therewith, plungers in said cylinders, means 55
pressure as may resist the entry of the replen
engageable with and operable to actuate simul
ishing f_luid.
taneously all of said plungers in said small cyl
It will be evident that I have provided a hold
inders to transmit power to said larger plungers
60 down mechanism which is vnot a general hy
to actuate the same, and said larger plungers_ 60
draulic system with pipes, master cylinders, being formed to comprise clamping elements.
valves and other complications. The machine is
V7. A hold down mechanism for shears com
ostensibly of simple mechanical design; yet it prising a series of work clamping elements, a
employs the powerful and advantageous hy
separate and self contained hydraulic operating
draulicY factor, but only in the zone of applica
unit for each element, a primary control plunger
tion and in the simple and desirable unitary for each unit, a secondary plunger for each unit
form,.whose advantages have been related. A operable by said primary plunger and formed to
machine so constructed is for the above reasons
provide a work clamping portion, and a pressure
not only less costly than a fully hydraulic one, bar engageable with all of said primary plungers
but is far more eñ‘lcient and economical to main
to actuate them simultaneously.
tain, since` it need not be laid upfor dismantled
Без категории
Размер файла
477 Кб
Пожаловаться на содержимое документа