Патент USA US2105402код для вставки
Jan. 11, 1938. v R, L_ BROWNLEE ' 2,105,402 ~HYDRAULIC HOLD-DOWN FOR SQUARING' SHEARS Filed Aug. 2, 1935 2 Sheets-Sheet l JáIL 11, 1938. R. |_. BRowNLEE 2,105,402 HYDRAULIC HOLD-DOWN FOR SQUARING SHEARS Filed Aug. 2, 1955 Z5 2 Sheets-Sheet 2 L@ Ö Z6 Y 2,105,402 Patented Jan. ll, 1938 UNHTED ÀT'ES ÈATENT OFFliÉE 2,105,402 HYDE ULÍC HOLD-DOWN FOR SQUARING SHEARS 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 times. ' 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. i 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. 2 2,105,402 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 20 tween them, said longitudinally extending bar being disposed between said side bars and guided thereby. , 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. . f 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. Y Y i 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 ROBERT LESLIE BROWNLEE.