US2908316A

US2908316A - Compact stretch-straightening mechanism with gripping heads having separate upper and lower sections composed of vertical laminations

Info

Publication number: US2908316A
Application number: US633129A
Authority: US
Inventors: Heinrich B Albers
Original assignee: Baldwin Lima Hamilton Corp
Current assignee: Baldwin Lima Hamilton Corp
Priority date: 1957-01-08
Filing date: 1957-01-08
Publication date: 1959-10-13
Anticipated expiration: 1976-10-13

Description

. Oct. 13, 1959 COMPAC HEA HAVING SEP COMPOSED Filed Jan. 8, 1957 ARATE OF VE UPPER AND LOWE RTICAL LAMINATI H. B. ALBERS 2,908,316 TRETCH-STRAIGHTENING MECHANISM WITH RIPPING R CTIONS '7 Sheets-Sheet l Oct. 13, 1959 BERS 2,908,316

COMPAC TRETCH-STRAIGHTE NG MECHANI WITH GRIPPING HEA HAVING SE RATE R AN L R SECTIONS MPOSE CO F VER L L NATIONS Filed Jan. 8, 1957 7 Sheets-Sheet 2 0&1

2,908,31 6 PPING Oct. 13, 1959 H. B. ALBERS COMPACT STRETCH-STRAIGHTENING MECHANISM WITH GRI HEADS HAVING SEPARATE UPPER AND LOWER SECTIONS COMPOSED OF VERTICAL LAMINATIONS 7 Sheets-Sheet 3 Filed Jan. 8, 1957 H. B. ALBERS COMPACT STRETCH-STRAIGHTE NING MECHANISM WITH GRIPPING HEADS HAVING SEPARATE UPPER AND LOWER SECTIONS COMPOSED 0F VERTICAL LAMINATIONS 7 Sheets-Sheet 4 Filed Jan. 8, 1957 Q v I G n OUODV a? 000 0033?? U 0): 0 0 6 0 W f aa o v v q 7 0 0 0/ v 0K0 e a Oct. 13, 1959 H. B. ALBERS 2,908,316

COMPACT STRETCHSTRAIGHTENING MECHANISM WITH GRIPPING HEADS HAVING SEPARATE UPPER AND LOWER SECTIONS COMPOSED 0F VERTICAL LAMINATIONS '7 Sheets-Sheet. 5

Filed Jan. 8. 1957 m DE Oct. 13, 1959 ALBERs 2,908,316

. COMPACT STRETCH-STRAIGHTENING MECHANISM WITH GRIPPING HEADS HAVING SEPARATE UPPER AND LOWER SECTIONS COMPOSED 0F VERTICAL LAMINATIONS Filed Jan. 8, 1957 7 Sheets-Sheet 6 H. B. ALB ERS Oct. 13, 1959 COMPACT STRETCH-STRAIGHTENING MECHANISM WITH GRIPPING HEADS HAVING SEPARATE UPPER AND LOWER SECTIONS COMPOSED OF VERTICAL LAMINATIONS '7 Sheets-Sheet '7 Filed Jan. 8, 1957 NJNE lmi

United States Patent COMPACT STRETCH-STRAIGHTENING MECHA- NISM WITH GRIPPING HEADS HAVING SEP- ARATE UPPER AND LOWER SECTIONS COM- POSED OF VERTICAL LAMINATIONS Heinrich B. Albers, Malveme, N.Y., assignor to Baldwin- Lima-Hamilton Corporation, a corporation of Penn- .Sylvania Application January 8, 1957, Serial No. 633,129

12 Claims. ,(Cl. 153-35) This invention relates to mechanisms for straightening metal plates, sheets or shapes which have become bent or warped, particularly along their longitudinal axes, after being rolled or extruded. These mechanisms effect straightening of such products by stretching the material beyond the elastic limit. The conventional stretching machine comprises a frame on which two gripping heads are mounted. One of these heads is adjustably secured to the frame so that objects of various lengths may be accommodated in the machine. Hydraulic pressure is applied to the other gripping head to move it away from the secured gripping head, and thus subject to tensile force the object being stretched. While tension is developed in the stretched object, compression forces will be set up in the frame.

Recently a demand has arisen for straightening sheets and plates which are much larger and thicker than those heretofore handled in existing stretching machines. The need has arisen for machines on which plates or sheets having a width of ten feet or more and a thickness of several inches can be stretched, and which necessitate pulling forces of a magnitude not heretofore employed. Several serious problems present themselves When it is attempted to adapt the present, known arrangements to a much larger capacity. Among these are the following:

(1) Gripping head castings would become undesirably large, not only because of their weight and difliculty of machining, but also because of the unequal stresses that are set up in such castings and the likelihood of failure due to internal defects. It has been proposed to build up the gripper heads from a plurality of substantially C-shaped laminations which were arranged side by side in planes perpendicular to that of the article to be stretched, the laminations being bolted together. In the case of straightening machines of very high capacities, however, each of these laminations becomes prohibitively large, and difiicult to handle and manufacture. Further, the throat portions of C-shaped laminations are subject to high stress concentrations which cannot be determined definitely by calculation.

(2) A high capacity machine built according to the laminated design as proposed heretofore would be relatively long in certain portions thereof because the gripping heads were connected to cross-heads by links extending outwardly from the gripping heads.

(3) The mechanism for shifting the adjustable gripping head poses difficulties because of the heavy weight to be moved, the long distance to be traversed, and the limited space available for accommodating the required mechanism.

It is therefore one of the principal objects of this invention to provide a high capacity straightening mechanism capable of producing large stretching forces, but which comprises gripping heads which can be readily manufactured, and in which the stresses can be definitely determined in advance and controlled.

It is a further object to provide a high capacity 2,908,316 Patented Oct. 13, 1959 straightening mechanism in which the space required for the gripping head connections is reduced.

It is also an object of the invention to provide a travel mechanism for the adjustable gripping head, which is compact and can easily be connected to the gripping head.

Further objects and advantages will become apparent in the following detailed description thereof.

In the accompanying drawings,

Fig. 1A is an isometric projection of the right-hand portion of a horizontal stretch-straightening machine embodying this invention, the projection being diagrammatic with certain details shown in a simplified manner.

Fig. 1B is a view similar to Fig. 1A and showing the left-hand portion of the machine, Fig. 1B being an extension of Fig. 1A.

Fig. 2A is partly an elevation of and partly a vertical longitudinal section through the adjustable gripping head of Fig. 1A, taken substantially on the line 2A--2A'of Fig. 3A.

Fig. 2B is a vertical longitudinal sectionshowing the reciprocable gripping head of Fig. 1B and taken substantially on the line 2B-2'B of Fig. 313.

Fig. 2C is a continuation of the left-hand portion of Fig. 2B and shows a section taken substantially on the line 2C-2C of Fig. 3C.

Figs. 3A, 3B, and 3C are plan views, partly in section, of substantially the portions of the machine shown inFigs. 2A, 2B, and 2C, respectively.

Fig. 4 is an enlarged detail of the range adjustment mechanism shown at the extreme right-hand end of Fig. 2A.

Referring to the drawings, there is shown a horizontal stretch-straightening machine for stretching plates or sheets. The article to be stretched is gripped adjacent its ends in upper and lower gripping jaws 10, 10' of spaced

gripping heads

20, 20. The heads are provided with slides 11, 11 operating on

rail surfaces

12, 12 on the upper faces of spaced

frame members

14 and 15 extending longitudinally of the machine and resting on the floor or base 16. The gripping head 20 is adapted to be adjustably secured and locked in adjusted position by means of hollow pins 30 carried by the head 20 and adapted to engage in one of a series of oval openings 31 formed in longitudinally extending columns or

girders

34 and 35 raised above

frame members

14 and 15. The

girders

34 and 35 may be supported in a plurality of standards 36 on a raised floor or base 37.

The gripping head 20 having been selectively locked in position by pins 30 engaging in oval holes 31 on each side of head 20, the stretching force is applied to the other gripping head 20. For thispurpose, fluid under pressure is admitted to inlets 40 (Fig. 1B) leading to cylinders 41, .42, 43 on one side, and cylinders 44 (Fig. 2B), 45, 46 on the other side. The rods of the pistons or rams of all of these cylinders are fixed in stationary cross-heads 50, 51 attached to

girders

34, 35 by bolts 52 and resting on the

frame members

14, 15,- one of the rams being shown at 47 in Fig. 33. On admission of fluid under pressure, all of the cylinders at both sides will be moved outwardly (to the left, in the drawing). The

cylinders

41, 42, 43 are mounted in a lug generally shown at 60, and the

cylinders

44, 45, 46 are mounted in a lug generally shown at 61, said lugs being rigidly attached to a cross-head (to be more fully described hereinafter) which in turn is a rigid part of gripping head 20' so that the latter is caused to move with the cylinders. As indicated in Fig. 1B, the lugs 60, 61 are supported on slides 67 engaging rail surfaces 68 of the

frame members

14, 15 and cooperating with the slides 11' on rail surfaces 12'. The pistons of the larger

central cylinders

42, 45 are provided with

rod extensions

62, 63 mounted in supports 64, 65 in a fixed frame 66. The total force applied to

cylinders

41, 42, 43, 44, 45, 46 is effective for moving the head 20' away from the head 20 to provide the stretching force.

The head 20' may be returned by pneumatic pressure acting on pistons or rams 70, 71 secured to cross-head 90' of head 20, said pistons operating in cylinders 72, 73 fixed in frame 66. Said cylinders 72, 73 are continuously connected to a source of pneumatic pressure so that when pressure is released in cylinders 41 to 46, the head 20 is returned by pneumatic pressure. The pneumatic pressure in these cylinders will also act to ,cushion the shock in case the part being stretched should break.

The gripping heads 20, 20' are designed to overcome the difficulties which, as pointed out in the introduction hereto, operated against the construction of a stretching machine of the capacity now found essential. The gripping head construction illustrated shows separate upper and lower sections indicated generally at 80, 81 (see Fig. 2A) and 80', 81' (see Figs. 1B and 2B). Each section is composed of a plurality of spaced

laminations

82, 83 and 82, 83', the spaces between the laminations being filled by inward links 84, 84 and outward links 85, 85', the links extending substantially vertically to cooperate with and connect the laminations of upper and lower sections. The laminations and interleaved links of upper and lower sections of both gripping heads are secured to each other by tubular pins 86, 86' about which the sections may tend to pivot under stress. In the space between upper and lower sections of gripping head 20 is positioned a cross head generally indicated at 90, and in the space between the upper and lower sections of gripping head 20' is positioned a cross-head generally indicated at 90'.

The cross-head 90 comprises a series of horizontal plates 91 (see Fig. 3A) and vertical plates 92, which may be Welded together to form an integral member which abuts against the inner surfaces of outward links 85 and is rigidly secured to the links by means of bolts 87 and a plate 88 bearing against the outer vertical faces of the links.

Each of the

girders

34 and 35 is in the form of a .U having upper and lower arms 97 and resting on one of the arms facing inwardly. At both of its sides the cross-head 90 is provided with upper and lower lateral extensions 95 extending above and below the arms 97 of each

girder

34, 35 and with an intermediate extension 96 extending between the upper and lower arms 97, the upper and lower extensions having circular openings 93 (Fig. 2A) and the intermediate extension having circular openings 99 therethrough forming bearing-surfaces for guiding and maintaining the pins 30 in their setting positions in oval openings 31 in the girders. The pins 30 are shown in the tom of cylinders movable on piston rods or stems 102, 103 secured to

frames

104, 105 which are supported on the extensions 95 of cross-head 90. The cylinders 30 'are movable into and out of the upper and'lower aligned openings 31 in the upper and lower arms 97 of the

U-shaped girders

34 and 35. When the cylinders are in their outward positions but register with a selected pair of openings 31, fluid pressure is admitted through the stems 102, 103 to force the cylinders 30 together and into the

openings

31, 99 where they lock the cross-head 90 (and, therefore, the gripper head 20) in position.

When it is desired to adjust the position of the gripper head 20, fluid pressure is admitted through suitable openings to force the cylinders 30 outwardly out of the aligned openings 31 so that the head 20 may be shifted. For the latter purpose a threaded stem 110 is bolted to each of the extensions 96 at the two sides of cross-head 90 and extends outwardly to a cylinder 112 to which it is rigidly connected. Each cylinder 112 is movable on a double-acting piston 119 and its rod or stem 114 which is releasably locked in position by means of a pair of range setting members 115, 116 movable in guides 117 formed in a head 118 fixed to the outer end of stem 114, the range setting members engaging one set of the oval openings 31 in

girders

34, 35. By admitting fluid under pressure into each cylinder 112 at one side or the other of piston 119, the cylinders 112 (and, with it, cross-head 90, head 20, and pins 30) may be shifted through a distance equal to the stroke of cylinders 112 relative to their stems 114.

In the case of a short article to be stretched, however, it may be necessary to shift the head 20 inwardly toward head 20' through a distance greater than the stroke in cylinder 1 12. To permit such greater movement a range adjustment is provided comprising said range setting members 115, 116. To vary the travel range, the setting members are moved towards each other out of aligned oval openings 31; thereafter the stems 114, together with head 118, may be moved relative to their cylinders '112 and within the arms 97 of the

girders

34 and 35 to a new position where the setting members register with a selected set of openings 31. The setting members are then moved outwardly into the selected openings to lock the stems 114 in the new position. To this end, each setting members 116 is fixed to a doubleacting piston 121 (Fig. 4) having a rod or stem 120 and engaging a bore 1240f the respective setting member 115 so that each member 115 and the associated member 116 with its piston 121 are movable relative to each other. Fluid pressure may be admitted below or above each piston 121 through

passages

122, 123 in stem 120 to move members 115, 116 towards or away from each other out of, or into, aligned openings 31. For example, when the par-ts are in the position shown in Fig. 2A, the locking pins 30 may be withdrawn from the openings 31 and fluid pressure may then be admitted between each piston 119 and the closed forward end of its cylinder 112 to shift gripping head 20 to the left in the drawings until the rearward end of each cylinder 112 is adjacent to or engages the respective piston 119. After withdrawing the setting members 115, 116 from openings 31, fluid pressure may be admitted between each piston 119 and the rearward end of its cylinder 112 to cause pistons 119, stems 114 and heads 118 to travel to the left in the drawing substantially the length of the cylinders 112. While the stems 114 move, the gripping head 20 will remain stationary due to its large mass. Setting members 115, 116 may then again be engaged in a selected set of openings 31 and gripping head 20 may again be shifted. Any required degree of travel inwardly by head 20 may thus be obtained by successively moving the stems 1:14 to the left substantially the length of their cylinders 112 at each adjustment.

The cross-head 90 (Figs. 2B and 3B) is constructed similarly to cross-head 90, and consists of a plurality of horizontal and vertical members 91', 92 welded together. The cross-head abuts against the inner surfaces of the vertical outward links and is rigidly secured to the links by means of bolts 87' and a plate 88 bearing against the outer vertical faces of the links.

As stated hereinbefore, the cross-head is provided with lateral lugs 60, 61 which connect it to and carry the movable cylinders 41 to 46 (Fig. 1B). Each of the lugs comprises a lateral extension of cross-head 90 for receiving the

central cylinders

42, 45, and caps 130 for mounting the upper and

lower cylinders

41, 43, 44, 46, the caps being secured to the extensions 95 by means of tie-rods 131. The gripping jaw linkage (Fig. 2B) of the reciprocable or force applying head 20' is carried by cross-head 90' and serves to move the jaws 10' into initial engagement with the sheet to be stretched. When the stretching force is applied to cylinders 4146, such force will be transmittedthrough lugs 60, 61 to y m-A" the cross-head 90. The stretching force will then be applied by cross-head 9.0 to the inner faces of outward links 85' whichtransmit it to the spaced laminations 82', 83' and thus to the jaws In a corresponding way, the gripping jaw linkage 100 of the fixed gripping head is carried by cross-head 90 and serves to move the jaws 10 into initial engagement with the sheet to be stretched. The stretching force applied to the sheet by jaws 10 is transmitted through the sheet to the jaws 10 and causes the latter to grip the sheet more firmly. The force is then transmitted through

laminations

82, 83 to outward links '85, to cross-head 90, and to pins in the oval openings 31 of

girders

34, 35. The reaction forces -at 50, 51 and atpins 30 act to place the

girders

34, 35 under compression so that they are stressed in the manner of columns. As the jaws 10, 10 bear against inclined faces of the

laminations

32, 82, 83, 83' and tend to move such faces apart from each other when stretching forces. are applied, the inward links 84, 84 will be subject to pull, whereas the

outward links

85, 85 will be subject to compression apart from the forces transmitted at the cross-heads 90, 90, the tension and compression stresses in the links being relatively small. The stress distribution in the

laminations

82, 82', 83, 83' is favorable since a stress-sustaining support in the form of inward links 84, 84 is provided at a short distance from the jaws 10, 10.

It will be understood that the

girders

34, 35 form a structure which operatively connects the gripping heads so that the

frame members

14, 15 are relieved from the transmission of stretching forces as known in the art. It will further be clear that, if suitable, the frame proper may be used to connect the gripping heads operatively in conventional manner.

The invention solves the problems which presented themselves in the building of high capacity stretching machines:

a. By providing separate upper and lower laminated sections for each gripping head, larger heads can be constructed than washeretofore possible, and the stress distribution is greatly improved by the arrangement described.

12. By providing cross-heads between the upper and lower laminated sections, it is possible to mount the pressure cylinders alongside of and connected to the crosshead of the pressure applying, reciprocable gripping head so as to obtain a more compact machine. This avoids mounting the cylinders a considerable distance outwardly and connected to the reciprocable head by long links as was heretofore the practice. Likewise, the locking means for the adjustable gripping head may be conveniently connected to the cross-head thereof.

c. By providing fluid motors and range adjusting mechanisms therefor to shift the adjustable gripping head, electric motors are eliminated for this purpose while keeping the stroke of the fluid motors within practical limits. The travel mechanism described can be arranged readily on the stretching machine and connected conveniently to the cross-head of the adjustable gripping head.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a horizontal stretching machine having a frame, a pair of gripping heads supported on said frame for relative movement longitudinally thereof, upper and lower jaw means movable on said heads for gripping the material to be stretched, and means for applying pressure to move said gripping heads away from each other, the improvement which comprises each gripping head having an upper section which supports said upper jaw means and a separate lower section spaced from the upper section and which supports said lower jaw means, each section being composed of a plurality of vertical laminations, and means for interconnecting each upper section and the respective lower section adjacent the inward ends of the '6 gripping heads facing each other and adjacent the other ends of the gripping heads, said interconnecting means including links pivotally connected at their ends to the respective upper and lower sections 2. In a horizontal stretching machine having a frame, a pair of gripping heads supported on said frame for movement longitudinally thereof, upper and lower jaw means movable on said heads for gripping the material to be stretched, locking means for securing one of said gripping heads relative to the frame in adjusted position, and means for applying pressure to the other gripping head to move it away from the adjustable gripping head, the improvement which comprises each gripping head having an upper section which supports said upper jaw means and a separate lower section spaced from the upper section and which support said lower jaw means, each section being composed of a plurality of vertical laminations, means for interconnecting each upper section and the respective lower section adjacent the inward ends of the gripping heads facing each other and adjacent the other ends of the gripping heads, said interconnecting means including links pivotally connected at their ends to the respective upper and lower sections, and a crosshead in each of said gripping heads and secured thereto between the sections of each. head, said locking means of the adjustable gripping head and said pressure applying means of the other gripping head being connected to the respective cross-heads.

3. A stretching machine as specified in claim 2, in which a fixed, channel shaped girder is provided at each side of said machine, the side walls of the channels being formed by arms of the girders, and lateral extensions are provided on said .crosshead of the adjustable gripping head, said extensions having upper and lower portions embracing the girders and intermediate portions protruding into the channels between the arms .of the girders, and in which said arms have aligned sets of openings therethrough along their length, and said upper, lower and intermediate portions have one set of aligned openings therethrough at each side of the adjustable gripping head, said locking means comprising pins guided in the openings of said upper and lower portions and when in locking position engaging selected openings in the arms of the girders as well as the openings in said intermediate portions to secure said adjustable gripping head to the girders.

4. A stretching machine as specified in claim 2, in which a fixed girder is provided at each side of said machine and has openings therethrough along the length thereof, and in which actuating means are provided for shifting the adjustable gripping head along said frame, said actuating means comprising at each side of the machine a cylinder element and a piston element cooperating therewith, fastening means for securing one of said elements at each side to the cross-head of said adjustable gripping head, and means for releasably securing the other of said elements at each side in selected openings in therespective girders.

5. A stretching machine as specified in claim 4, in which the means for releasably securing one of said elements at each side to the respective girders includes a pair of range setting members adapted to be moved into and out of the selected openings, guides for the members, and means for moving said members into said openings so as to fix said elements in adjusted position and for moving said members out of said openings so as to permit movement of said elements relative to said girders to other openings.

6. In a stretching machine, a frame, a pair of gripping heads supported on said frame for movement longitudinally thereof, one of said gripping heads being adjustably locked in position relative to theframe, the other of said gripping heads being reciprocable and adapted to have pressure applied thereto to move the gripping heads relatively to each other; each of said gripping heads having upper and lower jaw means movable thereon for gripping the material to be stretched, each gripping head comprising an upper section in which the upper jaw means is supported and a separate lower section spaced from the upper section and in which the lower jaw means is supported, each section being composed of a plurality of vertical laminations, means connecting each upper section to the respective lower section adjacent the inward ends of the gripping heads facing each other and adjacent the other ends of the gripping heads, said connecting means including links pivotally connected at their ends to the respective upper and lower sections, and a cross-head secured to each gripping head and positioned between the sections thereof, the cross-head of the reciprocable gripping head having a lateral lug at each side; a fixed cross-head mounted at each side of the machine, and a cylinder system and a cooperating piston systern at each side, one of said systems at each side being secured to the respective fixed cross-head, the other of said systems at each side being secured to the respective lateral lug' of the cross-head of the reciprocable gripping head. e

7. In a horizontal stretching machine, frame means, a pair of gripping heads supported on said frame means for movement longitudinally thereof, one of said gripping heads being reciprocable towards and away from the other head, the position of said other head being adjustable relative to the frame means, said frame means comprising a structure operatively connecting said gripping heads, a cylinder element and a cooperating piston element for shifting said adjustable gripping head relative to said frame means to change its position, one of said elements being secured to the adjustable gripping head, and means for securing the other element to said structure selectively in one of a plurality of positions along the length of said structure, whereby the range of shifting movement of the adjustable gripping head may be varied.

8. A stretching machine as specified in claim 7, in which said structure has openings along the length thereof, and said last-named means includes a range setting member for engaging a selected opening in said structure. I

9. A stretching machine as specified in claim 8, comprising locking means for securing the adjustable gripping head to said structure in adjusted position, said locking means including a locking pin movable into and out of one of said openings when not engaged by said range setting member.

10. A stretching machine as specified in claim 7, in which said structure comprises a channel shaped girder having lateral arms and aligned pairs of openings through said arms along the length thereof, and in which said last-named means includes a pair of range setting members adapted to engage a selected pair of openings in said girder, mechanism being provided for moving the setting members into said pair of openings to fix said other element in selected position and for withdrawing the setting members to permit movement of said other element relative to the girder to another pair of openings therein.

11. A stretching machine as specified in claim 10, in which said mechanism includes a double-acting piston attached to one of said range setting members, the other member having a bore in which said piston operates.

12. In a horizontal stretching machine having a frame, a pair of gripping heads supported on said frame for relative movement longitudinally thereof, upper and lower jaw means movable on said heads for gripping the material to be stretched, and means for applying pressure to move said gripping heads away from each other, the improvement which comprises each gripping head having an upper section which supports said upper jaw means and a separate lower section spaced from the upper section and which supports said lower jaw means, each section being composed of a plurality of vertical laminations, and means for interconnecting each upper section and the respective lower section, said interconnecting means including vertical inward links disposed adjacent those ends of the gripping heads which face each other and spaced from said movable jaw means, vertical outward links adjacent the other ends of said gripping heads, and pivots connecting the ends of said inward and outward links to the respective upper and lower sections, a crosshead being provided in the space between the sections of each gripping head in abutting relation to the respective outward links.

References Cited in the file of this patent UNITED STATES PATENTS 998,455 Benton July 18, 1911 1,903,638 Sykes Apr. 11, 1933 2,009,829 Williams July 30, 1935 2,164,343 Nighthart July 4, 1939 2,315,971 Lake Apr. 6, 1943 2,391,657 Tavelin Dec. 25, 1945 2,473,109 Schneider June 14, 1949 2,523,871 Mavor Sept. 26, 1950 2,685,260 Auger Aug. 3, 1954 2,727,556 Albers Dec. 20, 1955 FOREIGN PATENTS 584,682 France Nov. 24, 1924