US3046874A - Press brake - Google Patents

Description

July 31, 1962 R. F. DEHN 3,046,874

PRESS BRAKE Filed March 21, 1960 4 Sheets-Sheet 1 JNVENTOR Poy F Dif/N Arron/Veys July 31, 1962 R. F. DEHN Filed March 21, 1960 PRESS BRAKE nl 56 55,-?? ;:L

5 4 5 l l l l l l 4 Sheets-Sheet 2 ATTORNEYS` R. F. DEHN 3,046,874

PRESS BRAKE 4 Sheets-Sheet 3 July 31, 1962 Filed March 2l, 1960 m TN N EH W@ E w on 'l Juli L@ g; :MELE E@ F. m; mmgm- July v31, 1962 R. F. DEHN PRESS BRAKE 4 Sheets-Sheet 4 TUI Filed March 21, 1960 J :41 d l INVENTOR.

A TmRNEYs United States Patent On ice 3,li46,874 Patented July 31, 1962 3,046,874 PRESS BRAKE Roy F. Dehn, Wickliie, Ohio, assignor to The Cleveland Crane d: Engineering Company, Wicklite, Ohio, a corporation of Ghio Y Filed Mar. 21, 1960, Ser. No. 16,323

4 Claims. (Cl. 10U-256) Y This invention relates to press brakes, platen presses, or like devices having a movable work performing member actuated by a drive motor through power and return strokes, and having predetermined characteristics of rate and extent of movement of the movable member.

One of the principal objects of the present invention is the provision of a novel and improveddevice such as a press or the like having a motor operated ram member for carrying tool or punch means for stamping, punching, bending or otherwise fabricating sheet material or the like, and which device includes ram motor control means for changing the rate of movement of the ram member to a faster or slower speed during Aa predetermined portion of the power stroke and for stopping or limiting the movement of the ram`member at the bottom or end of the power stroke. j

A more specific object of the present invention is the provision of a new and improved press or metal working device having a reciprocable ram member operated by a reversible motor means such as a iluid pressure motor which is responsive to control means including rst, second and third'switch means for respectively determining the end or bottom of the power stroke, the end or top of the return stroke, and for effecting a change in speed or rate of movement of the ram member during the power stroke, and switch actuating means mounted for movement with the ram member and including adjustably positioned cams at least one of which is movable by cam positioning and indicating means by which the cam can be readily md accurately set or adjusted to predetermined positions whereby the press brake can be rapidly conditioned to perform a series or sequence of different work strokes Without undue loss of time between strokes for adjustmentpurposes.

The invention resides in certain constructions and combinations and arrangements of parts and further objects and advantages will be apparent to those skilled in the art to which it relates from the following -detailed description of the preferred illustrative embodiment of the invention described with reference to the accompanying drawings forming a part of this specification, and in which:

FIG. l is a front elevational view of -a plate bending brake or press embodying the present invention;

FiG. 2 is a side elevational view on an enlarged scale of a portion of the stroke control means of the press of FIG. l as viewed from the right;

FIG. 3 is a side View, partly in section, of a portion of the stroke control means taken substantially along line 3-3 of FIG. 4;

PIG. 4 is a sectional view of the stroke control means taken along lines 4 4 of FIGS. 2 and 3, and

FIG. 5 is a front elevation of the adjusting and indicating portion of the stroke control means.

The present invention is considered especially applicable to bending presses or brakes and is herein shown as embodied in such a press. It is, however, to be understood that the invention is applicable to various types of presses and other machines and the present showing is intended to 'be merely illustrative of the invention and not to be restrictive in any manner.

Referring to the drawings, the reference character A designates a frame comprising stress-resisting, plate-like end members or side housings 1t), 11 having aligned openingsin their front edges; a combination reservoir and a sump 12 interposed between and supported by the upper ends of the sidehousings 1G, 11; and a table or die support 1'3 supported rand iixedly secured to the top of a heavy plate or stationary blade 14 extending between and iixedly secured to the side -housings 10, 11. f

A movable ram or upper blade, designated generally by the reference character B, located directly above the table or die support 13, is slidably suported by the side housings -for linear movement toward and away from the table or 'die support. The lower edge of the ram B is `adapted to carry a suitable punch or other tool.

The ram or movable blade B is adapted to be reciprocated toward and away from the table or die support 13 by reciprocating type double acting uid pressure motors designatedgenerally by reference characters C, D. The cylinders 20, Z1 of the motors C and D, respectively, are connected to the side housings 10, 11 respectively, of the press frame `and the piston rods 22, 23 of the motors are connected by ball and socket connections or joints 24, 25 to the blade B adjacent to opposite ends thereoff The principal pressure uid, preferably oil, for operating the hydraulic motors C, D is supplied by two constant volume unidirectional main pumps E, F driven byV anpelectric motor 26. rl`he -pumps E, F supply pressure duid-tothe hydraulic motors C, D respectively. An auxiliaryor third constant volume unidirectional pump G driven by an electric motor 27in conjunction with an electronic control, supplies pressure uid to the hydraulic motors C, D for maintaining a predetermined blade or ram` attitude. The pumps and motors supported upon the top of the reservoir 12 which is in the form of an elongated rectangular oil tank or sump extending between and connected to opposite end housing members 10,11.

' The hydraulic and electrical circuits for controlling the reciprocation of the blade B through its power and return strokes may be substantially the same as are described in United States Patent No. 2,958,199, issued November l, 1960, and assigned to the same assignee to which this application is assigned. Y

The circuits described in the mentioned copending application include switch means to which the ram drive means are responsive to end or limit the down or power stroke; to end or limit the up orV return stroke; and to effect a change in speed or rate of movement of the ram or blade member. Y In the press described hereinafter as embodying the present invention, switch means cor-responding to the just mentioned switch means are referred to as a down limit switch 35; an up limit switch 36;,and a rapid advance switch 37; as are best illustrated in FIGSQZ, 3 and 4 hereof.

The down limit switch 35 is mounted or fixed by suitable bracket means to one side housing 11 of the press frame and is adapted to be actuated by an adjustably positioned cam 40 which is mounted for movement with the ram or blade B. Y Y l The up limit switch 36 -and the rapid advance switch 37 are also mounted by suitable bracket meansV to the side housing 11 and are adapted to be actuated by adjustably positioned cams 41 and 42 respectively which are mounted for movement with the ram or blade VB.

Adjusting and indicating means, generally indicated at 45, are provided for accurately positioning the down limit switch actuating cam 40 with respect to the blade B for predetermining or controlling the down or bottom position of the blade B with respect to the die means 13 when the blade isat the bottom or extreme down position thereof at Athe end of a power or working stroke. The adjusting and indicating means 45 will be described in more detail hereinafter. Suiiice it to say for the present that it permits the rapid and accurate changing of the strokeA length characteristics between strokes `or series of strokes 3 1 without the expenditure of undue between. n

T he up limit switch actuating cam 41 and the rapid advanceswitch actuating cam 42 are mounted on an elon- .gated` scale 50 having -a groove 51 one one side thereof and having graduation markings inscribed or Vprinted thereon. p The scale t) is clamped to one edge of a mounting block S2 which; is suitably secured to the blade B as'by screws 53. The clamping of the scale to the block 52 is elected by clamp elements 55 and screws 56.

The cams 41-and 42 are adjustablysecured to Vthe scale 50 byclamp members 58 and y59'respectivel'y, and

Vthumb screws 60, 61 extending throughthe Yclamp members 'into the cams.

The thumb screws 60, 61 can be loosened to permit the cams 41, 42 to slide along the scale 50 Vfor adjustment of-the upper limit of the return` s stroke Yand adjustment of the point of change of the rate of movement of the ram member.

Thev up limit switch 36 is provided withV a pivoted, arm

Vmember 65fhaving a roller 66 which is adapted to be engaged and moved by the surface of the cam 41 for actuation of the switch. Therapid advance switchV 37 isV similarly provided with a pivoted arm memberY 67 having a roller 68 which is .adapted to be engaged and moved by the surface-of the-cam 42 for actuation'of that switch.

The ram member or blade B is illustrated in FIG. 2 in its up position and, when a power stroke is commenced, as by an operator depressing the foot switch 9,6, the actuating lroller 66 of the switch 36 will be released by the -cam 41 for movement to its dotted line position. As the bladeV B returns toits FIG. 2 position, afterV having made a power stroke as Vwilly be described hereafter,v

the cam 41 actuates the 4switch 36V stopping upward movementy of theV blade. Y l

The rate of movement or speed of the blade B during the power and return strokes is under the control of theV rapid advance switch 37, and when the elongated cam 42 yreleases the roller 68 for movement to its dotted line position, thev drive means will respond -by changing the rate of movement of the blade B to a slower speed. The blade B can be advantageously controlled by the elongated cam 42 to be moved at a rapid rate through the major por-y tion of the power stroke, and to1 be slowed to a relatively reduced speed during the terminal portion of the power stroke, whereby the down or bottom position of the blade at the end of the power stroke can be more accurately controlled because the blade is then stopped Ifrom the Y The down limit switch is provided with a pivoted arm 69 having aroller 70 which is adapted to be en- Y -gaged and moved by the surface of the cam for actuation of that switch. Y Y

The down limit switch actuating camy 40 is adjustably clamped jbymeans of' a clamp memberV 71 and a thumb screw 72 to an Y elongated slide member 73.

The latter, slide member 73, extends in a direction parallel to the direction of travel or stroke of the ram member or blade B, and is slidably mounted withrespect there- "to by means ofrthe mounting' block 52.

The slide member 73isV conveniently provided with anges 75 andf76 connected by la web portion 77, with theflange 75 4slidablyreceived in a complementary.` T- shaped groove in the block 52. p An elongated gear rack 79 is provided on one side of the web portion 77 and serves as part of the adjusting andindicating means 45.

The adjusting and indicating means includes a rota-` table control knoh90 which is adapted, through Vgearing more particularly described hereafter, to 'move the slide aoaesie amounts of time theres l Y Y 4 member 73 in thexsupporting block 52 Yso vas to position` the cam 40 and thereby adjust the down position of the blade B at the end of its power stroke. A rotation indi-V catoror counter denoted generally at 91 is coupled to the'V knob 90 by suitable gearing and is preferably o f the type which displays numbers in a window as at 92. yThe counter 91 is 'conveniently geared so that thenumbers displayed thereby arerelated to movement of the slide member, and hence the blade down position, ingterms of hundredths .of an inch. Y

The adjusting and indicating means 45 includes a housing comprising a :base 94 anda cover 95 both secured to the face of the blade B as by screws V96. The knob is secured to a shaft 98 which is supportedfor rotationV in -suitable bushings or bearings inthe base 94 and coverV 95 of the housing. Y -A pinion 99 is Secured to the shaft; 98V for rotation therewith and is in meshing and drivin relation with a larger gear 100. f y r A shaft 1G2is connected to the gear 16'0 andY extends throughaligned openings 103 and 164 in the blade B and in the block 5,2 respectively. The shaft 102is supported for rotation by suitable bearings in the block 52 andthe 4.ba-se member 94, and hasVV connected theretoaV pinion ii05.V The pinion 105 is in meshing engagement with the teeth ofthe rack 79 and it will be recognized that rotationof the y'knob 90l will result in reduced rotay tion of the pinion 105, and consequent movement of the slide member 73 in the block 52. Y n

In order to prevent inadvertent movement of the slide Y 73 and its associated cam 40, a locking knob 11GV is pro-r.v vided. The knob is tbreadedly engaged on a threaded end 111 of the shaft 102 which extends outwardly of the cover 95'.l Rotation of the knob 111i in a sense to advance it along the threaded portion 111 ofthe shaft,

-102 will draw the Ishaft and the gear 1G19 toward the knob j 110 until the gear `10() is tightly clamped' against the cover 95 thereby preventing rotation of the gear 100 and the shaft 102.

The counter 91 has an -input shaft 114 which `carries a gear 115. A gear 116 is secured to the shaft 98 `for rotation therewithand is in driving relation to the gear ,116.

The counter 91 is thereby 4coupled to the knob 90 anclis i adaptedto display or indicate the position of the cam 4 0. Y In setting up the press, the ram member or blade'B is run to its uppermost position with respect to the .table 14. The locking knob 110 is rotated in -a manner to release the gear 100` and the shaft 102 for rotation, and the adjusting knob 90 is rotated in -a direction to bring the figures of the Vindicator 91 -to 1a zero position. kln doing so the slide member y73 will be brought to its full line position as shown inUFIG.H3. The cam 40 isY then adjusted along the flange 76 of theAslide member 73 to a position which just tripsy or` actuates Ithe down limit` switch 35. I f

The knob 90 is then rotated in a direction to raise the slide member 73, and the cam 40 carried thereby, to aV position where the figures of the indicator 91 indicate the s required stroke length to effect the desired bend. At this position, which is represented in dot-dash lines in FIG.V 3., the shaft 102 is locked through the agency of the knob 11G thereby securing the cam 40 in its desired position. r[The reading of` :the indicator means 91 may then be recorded and it will be recognized that thereafter the camV 4t) can bey shifted toxaV subsequent position and then returned to its present position by simply rotating theknob 90 until the recorded number again appears on the indicats ing means 91. Y, l

A series of positions :of the cam 40 can be recorded inv terms of the figures displayed on the indicating'means 91 so that a series of strokes for eecting different bends can be'carried out 'on the press with-av minimum yof time being expended between such strokes for adjusting theV position of the down limit switch actuating cam 40.

Icam 42 and as effecting ya decrease in speed when released. It will be apparent that in some work ,applications of the press the relationship could be reversed so that a decrease in speed would be effected upon iactuation of the switch 37. It will .also be apparent that although the invention has been described with reference to a press having hy draulic cylinder type motors for moving the ram member, the invention may as well be embodied in presses having ram members driven by electric motors yor other means.

From the foregoing detailed description of a specific embodiment of the invention, and from the accompanying sheets of drawings, it will be appreciated that there has been provided by the invention an improved press structure including means for rapidly :and accurately changing the eective length of the power -or work stroke of the press -by adjusting the position of the down limit switch yactuating cam. It will also be lappreciated that the means 4for carrying out the adjustment of that cam is embodied in a mechanism which is simple and economical in construction and yet is rugged and well able to withstand repeated shocks during use of the press without impairment of accuracy.

Although the invention has lbeen described in a detailed manner with reference to la specific embodiment thereof, it is understood that the invention is not limited thereto but rather includes all such modifications, adaptations and uses thereof as yare reasonably embnaced by the scope of the claims hereof.

Having described my invention, I claim:

l. A device of the character described comprising a frame; a ram member mounted for reciprocating movement through power and return strokes with respect to said frame; drive means for effecting said movement of said ram, :and control means for selectively controlling the length of lsaid power stroke including a power stroke limit switch, ya slide member mounted on one side of said ram for vertical movement :therewith and for sliding movement relative thereto, a cam member for operating said switch, means adjustably mounting said cam member on said slide member, .a gear nack on said slide member, a

shaft extending from -a second side of said ram through said ram to `said one side thereof on which said slide member is mounted, Ia pinion mounted on said shaft and meshing with said rack on said slide member, gear means mounted on the end of said shaft adjacent said second side of said ram, means for rotating said gear means and shaft so as to move said slide member for .adjustably positioning said cam, and means for `locking said shaft to said ram against rotation relative thereto.

2. A device of the character defined lin claim 1 wherein said locking means includes a housing member secured to said second side of said ram :and means for clamping said gear means against said housing member.

3. A device as defined in claim 1 further including indicator means and means connecting said indicator means to said gear means to cause said indicator means to indicate the position of said cam.

4. A device of the character describe-d in claim 1 further including `another switch for effecting a 'change of speed of said ram member during said power stroke, |another cam member mounted for movement with said ram member to actuate said other switch `for effecting a change of speed of said r-am member during a portion of said power stroke, and means for adjustably positioning sai-d other cam element with respect to said ram member to cause said cam element to actuate said other switch during a selected portion of said power stroke.

References Cited in the le of this patent UNITED STATES PATENTS Switzerland May 16, 1953

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