US3033548A - Quenching fixture - Google Patents

Description

May 8, 1962 A. s. FRENCH QUENGHING FIXTURE 2 Sheets-Sheet l Filed June 18, 1959 ATTORNEY May 8, 1962 A. s. FRENCH 3,033,548

QUENCHING FIXTURE Filed June 18, 1959 2 Sheees-Sheerl 2 IN VENTOR ALBERT S. FRENCH BY w@ ATTORNEY Unite 3,033,548 ce y Patented May 8, 1962 of Ohio Filed June 18, 1959, Ser. No. 821,144 3 Claims. (Cl. 266-6) This invention relates to the art of quench hardening or quench strengthening metals, and more particularly to a fixture for preventing warpage of structural angle iron during quenching.

Structural angle iron is usually produced in the steel mills by a process known as hot rolling. Such hot rolled angle irons normally have relatively low tensile strengths making it necessary to use for a given load situation a greater weight of iron than would be necessary if the metal had a higher tensile strength. It is known that the tensile strength of iron can be increased by heating the metal to an elevated temperature, e.g., approximately l400 F. and then quenching it at such a rate that the internal micro structure of the steel is changed to one having a much higher tensile strength than that of hot rolled steel. One of the difficulties, however, with such quench hardening and quench stren-gthening procedures is the uneven expansions and contractions caused by the heating and the quenching which give rise to excessive distortion in the final quench strengthened product. The problem is particularly severe as the size of the angle iron to be quench-strengthened is increased.

The present invention is directed to a novel fixture which positively prevents any substantial distortion of such angle irons during such a quench strengthening operation, even for angle irons as large as 8" x 8" X 1" in cross section and as long as in length.

In accordance with the present invention, there is provided a quench fixture for large angle irons comprised of upper and lower rigid platens of a length greater than the irons to be quench-strengthened and so constructed and arranged as to receive between them the angle which is to be quench-hardened, but so as to permit the easy entry of water or other quenching medium into contact with the iron. Such platens are arranged in combination with power operated means for moving the platens into firm engagement with both sides of the angle to prevent warping during the quenching operation.

Further in accordance with the invention, the surfaces of the platens directly engage opposite sides of the angle iron, but such surfaces are recessed at spaced points opposite to surfaces of the opposite platen so that the platens will have a maximum engaging surface with the angle iron, but still will not interfere with the quenching operation.

. It is an object of t is invention to provide a novel and improved fixture for holding a structural sized angle during quench hardening of the latter.

It is also an object of this invention to provide such a fixture which positively prevents the structural angle from becoming distorted to any substantial extent as a result vof such quench hardening.

Another object of this invention is to provide such a fixture which does not interfere with the effective quench hardening of the structural angle.

Further objects and advantages of this invention will be apparent from the following detailed description of a presently-preferred embodiment thereof, which is illus- 'trated inthe accompanying drawings.

4broken away for clarity showing the quench fixture of the present invention;

FIGURE 2 is a fragmentary top plan view thereof on an enlarged scale;

FIGURE 3 is a-vertical section taken along the line 3 3 in FIG. 1;

FIGURE 4 is a fragmentary vertical section taken along the line 4-4 in FIG. 1; and

FIGURE 5 is an enlarged section taken along the line 5--5 in FIG. 3 and showing the chamfered edges of the plates on the upper and lower platens which engage the apart in succession along the fixture,as best seen in Y FIG. l. ,Each of these plates 13 is relatively rigid, although capable of a certain degree of flexing, and each defines at its upper end an upwardly facing, V-shaped seat for receiving and supporting the structural angle member 14 which is to be quench hardened. As shown in FIG. 3, this V-shaped seat is defined by top edges 15 and 16 on each plate 13 which edges extend away from each other laterally and upwardly at opposite 45 angles to the horizontal. As shown in FIG. 5, each of these top edges is beveled or chamfered at the opposite faces of that plate for a purpose which will be stated hereinafter. The beveled portions are designated by the reference numerals 16a and 16h at the edge 16 of the plate 13 in FIG. 5.

As shown in FIG. 3, each of the top edges 15 and 16 of each plate 13 is formed with four evenly spaced rectangular notches 17. Another upwardly facing rectangular notch 18 is formed in each plate 13 at the bottom of the V-shaped seat between the edges 15 and 16. The several longitudinally spaced apart plates 13 are all identical, with the top edges 15 of all lying in a common plane and the top edges 16 of all lying in a common plane.

The lower platen 1t) also includes a pair of longitudinal side bars 19 and 20 (FIG. 3) which run lengthwise of the lower platen in spaced relationship above the base angle irons 11 and 12, as best seen in FIG. 3. These side bars are rigidly attached to the opposite edges of the several plates 13 by welding.

The upper platen of the fixture includes a rigid cylindrical pipe 21 which extends lengthwise above the lower platen 1t). A plurality of longitudinally spaced apart plates 22 are welded to the lower side of pipe 21, extending downward therefrom toward the respective plates 13 on the lower platen, as best seen in FIG. 3. Each of the plates 22 on the upper platen is aligned vertically with the corresponding plate 13 on the lower platen. As shown in FIG. 3, each plate 22 is V-shaped at its lower end, presenting bottom edges 23 and 24 which extend upward and laterally outward at opposite 45 angles to the horizontal. As shown in FIG. 5, these edges are beveled or chamfered at their Opposite faces, the beveled portions of edge V24' being indicated by the reference numerals 24a and 24b. These bottom edges 23 and 24 on the plates 22 of the upper platen engage the upper faces of the structural angle 14 which is to be quench hardened. At each of these bottom edges 23 and 24, there are formed four notches 25 of rectangular cross section which are staggered or offset with respect to the upwardly facing notches 17 formed in the top edges of the respective plate 13 on the lower platen. Also, at the intersection of the edges 23 and 24, at the crotch of the V, a notch or cut away portion 26 is provided.

In one practical embodiment, the plates 13 and 22 on the lower `and upper platens are each 5%: inch thick and are spaced apart in succession lengthwise of the xture 3% inches. In this embodiment, the upwardly facing notches 17 in each plate 13 on the lower platen are each 3A inch wide, neighboring notches 17 being spaced apart from each other a distance of 1% inches, and the notch 18 is inch wide and is spaced from the adjacent notches 17 a distance of 1% inches. In this embodiment, the downwardly facing notches 25 on each plate 22 on the upper platen are each 34 inch wide and spaced apart from each other a distance of 1%t inches, with the lowermost pair of these notches 25 being located a distance of 1% inches along the respective lower edge from the crotch of the V. By virtue of this arrangement, the notches 25 in the plates 22 of the upper platen are positioned opposite solid portions of the upper edges 15 and 16 of the respective plates 13 in the lower platen, while the notches 17 in the upper edges of the plates 13 are positioned opposite solid portions of the respective plates 22 at their lower edges.

In order to insure proper vertical alignment between the upper and lower platens, there are provided a plurality of stabilizer bars 30 which are rigidly connected to the upper platen 21 at its opposite sides and which extend downward therefrom. As best seen in FIG. 4, each stabilizer bar 30 is Welded to a plate 31 which is attached at its opposite ends to an adjacent pair of the plates 22 on the upper platen, as shown in FIG. 1. Each stabilizer bar 3b extends vertically downward and is snugly, but slidably, received in a guide member 32 which is welded at its opposite ends to the longitudinal side bar 19 on the lower platen. This guide member 32 defines a vertically extending opening of rectangular cross section which slidably receives the corresponding stabilizer bar 30. In the embodiment illustrated, there are four such stabilizer bars 30 and guides 32 on each side of the. tixture. It has been found in practice that this arrangement insures that the upper and lower platen will move directly toward and away from each other when actuated.

Suitable power-operated means is provided for selectively moving the upper and lower platens together to clamp the structural angle 14 -between them just before quenching and to move the upper and lower platens apart to release the angle following quenching. While this power-operated mechanism may take severall different forms, in the preferred embodiment it comprises a toggle mechanism lactuated by an air cylinder.

Referring to FIGA, the air cylinder 40 is bolted on top of the pipe 21 near one end thereof. A piston (not shown) is reciprocably mounted inside the cylinder and is coupled to a reciprocatory shaft 41. Suitable air inlet and outlet fittings are provided at 42 and 43, respectively.

The piston shaft 41 is coupled pivotally through a yoke 41a to a pair of rigid links 44. At their opposite ends the links 44 are coupled pivotally through a cross pin 47 to an elongated shaft 45 which extends lengthwise across the top of the upper platen.

A plurality of toggle links 46 are pivotally connected at their upper ends to the shaft 45 at spacedpoints along the latters length. This pivotal connection is provided by a cross pin 47 in each instance.

As shown in FIG. 3, each such toggle link is composed of two legs 48 which are `joined by a connecting plate 48a, the complete unit being of approximately inverted U-'shape in cross section, as shown in FIG. 3, with upstanding ears 49 connected to the pivot pin 47. Each such toggle link straddles the pipe 2-1 of the upper platen with the opposite legs 4S of the toggle link being spaced from the pipe 21, as best seen in FIG. 3. At each toggle link 46 there is provided a shaft 50 which extends from front to back through the middle of the pipe 21 and interconnects the lower ends of the respective opposite legs 48 of the toggle link. A suitable flanged bearing 51 is engaged between the lower end of each toggle linkage leg 48 and the adjacent end of the shaft 50 so that the toggle link 46 can turn with respect to the shaft 50. The shaft Si) is tightly received by the pipe 21 so that any vertical movement of the shaft Sil will be imparted to the upper platen.

Each toggle link 46 also presents a pair of legs 52 which respectively extend upward from the lower ends of the legs 48, as shown in FIG. l. As best been in FIG. 3, these legs 52 diverge outwardly away from the Velti-` cal planes of the respective lower ends of the legs 48. At their outer ends the legs 52 `carry horizontal pins 53 which are pivotally connected to downwardly extending links 54. At their lower ends the links 54 are attached to bolts 55. The lower ends of the bolts 55 are attached to inverted U-shaped links 56 which are pivotally mounted on fixed pins 57. The respective pins 57 are supported ixedly from the lower platen. Thus, as shown in FIG. 3, each pin 57 is mounted at one end in the longitudinal reinforcing bar 19 or 20, and is mounted at its opposite end in a bracket 58 which is welded to the base angle iron 11 or 12 and extends upward therefrom. With this construction the respective bolts 55 are pivotally supported from pivots 57 which are iixed on the lower platen.

In the operation of this mechanism, when it is desired to spread the upper and lower platens away from each other, the air cylinder 40 is operated to move the piston shaft 41 to the right in FIG. l. The resulting movement of the shaft 45 to the right causes the several toggle linkages to move the upper and lower platens apart from each other. Conversely, when the air cylinder 40 is operated to move the piston shaft 41 to the left, the resultant movement of the shaft 45 to the left causes the several toggle linkages to move the upper and lower platens toward each other.

In the use of this fixture in a quench hardening operation, the angle iron 14 which is to be quenched after having been heated to the quench hardening temperature is drawn lengthwisey across the upwardly facing V-shaped seats defined by the plates 13 on the lower platen. This is done when the upper and lower platens are spread apart a suliicient distance to permit such insertion of the angle iron. Immediately after seating the angle iron 14 on the lower platen, as described, the air cylinder 40 is actuated to cause the upper and lower platens to move toward each other and thereby move into clamping engagement with the inner and outer sides of the angle iron 14, as shown in FIG. 3. Then the fixture with the angle iron clamped in place is dunked rapidly in a tank filled with quenching fluid such as oil or water. During such quenching, the fixture holds Y the angle iron 14 throughout its length in such a manner as to prevent the angle iron from distorting transverse to its length as a result of such quenching. The notches 17 and 18 in each plate 13 on the lower platen Iand the notches 25 and 26 in the plates 22 on the upper platen permit the circulation of the quenching liquid across the inner and outer faces of the angle iron 14 so that the quenching takes place as effectively and about as quickly as it would take place in the absence of this fixture. Since the notches in the upper platen plates 22 are in staggered relationship with respect to the notches in the lower platen plate 13, there is no appreciable tendency for the angle member 14 to become distorted at these notches. As already pointed out in the preferred embodiment, the work-piece engaging edges of the plates 13 and 22 are beveled or chamfered, as shown in FIG. 5. This is to permit lengthwise slippage of the angle member 14 as it contracts during quenching. This is highly desirable since the fact that such longitudinal contraction of the angle member is permitted to take place further reduces the tendency for strains to be set up in the angle member which would tend to produce distortion of the angle member transverse to its length. Also, the plates 13 and 22 are capable of flexing to a slight degree, which further tends to permit longitudinal contraction of the angle iron 14 without transverse distortion thereof.

While there has been described in detail herein and illustrated in the accompanying drawings a specific presently preferred embodiment of this invention, it is to be understood that various modications, omissions and refinements which depart from the disclosed embodiment may be adopted without departing from the spirit and scope of this invention.

Having thus described my invention, l claim:

l. A fixture for holding elongated heated structural shapes of substantially uniform cross section as such shapes are subjected to a quenching action, said fixture being comprised of a pair of platens of generally equal length longer than the length of the structural shape to be held, each platen being comprised of an elongated structural member rigid in both the horizontal and vertical directions transverse to its longitudinal length, a plurality of similar and equally spaced plates rigidly fastened to said structural member and each having a plane perpendicular to the longitudinal length thereof, each plate having an edge extending transversely to the longitudinal length of said member with the edges of each plate of each platen all being in a common plane, the plane of the edges of one platen being parallel to the plane of the edges of the other platen to define an elongated work piece receiving space of uniform thickness in both a longitudinal and transverse direction, the plates of one platen being spaced the same distance apartand in the same transverse plane as the plates of the other platen, the edges of each plate having a plurality of spaced notches extending generally transversely to the plane of the plate and longitudinally of the platen, the notches of one plate of one platen being so spaced an arranged as to be offset from the notches of the opposed plate of the other platen and means for forcefully bringing said platens into pressure engagement with a work piece positioned therebetween whereby when saidwork piece is placed in a quench tank, the work piece is held with a maximum degree of rigidity while exposing the maximum surface area of the work piece to direct contact with the quenching liquid.

2. A fixture yfor holding elongated heated structural shapes of substantially uniform cross section as such shapes are subjected to a quenching action, said fixture being comprised of a pair of platens of generally equal length longer than the length of the structural shape to 'be held, each platen being comprised of an elongated structural member rigid in both the horizontal and vertical directions transverse to its longitudinal length, a plurality of similar and equally spaced plates rigidly fastened to said structural member and each having a plane perpendicular to the longitudinal length thereof, each plate having an edge extending transversely to the ngitudinal length of said member with lthe edges of each plate of each platen all being in a comm-on plane, the plane of the edges of one platen being parallel to the plane of the edges of the other platen to dene an elongated work piece receiving space of uniform thickness in both a longitudinal and transverse direction, the plates of one platen being spaced the same distance apart and in the same transverse plane as the plates of the other platen, the edges of each plate having a plurality of spaced notches extending generally transversely to the plane of the plate and longitudinally of the platen, the notches of one plate of one platen being so spaced and plate of the other platen and means arranged as to be offset from the notches olf the opposed plate of the other platen and means for forcefully bringing said platens into pressure engagement with a work piece positioned therebetween, a plurality of toggles pivotally mounted on one platen on longitudinally spaced transversely extending axes, each toggle including a first arm mechanically connected to the other platen, `and a second arm and power means interconnecting the second arm of each toggle for pivoting said toggles and moving said platens into pressure engagement with a work piece positioned in the work piece receiving space of said fixture.

3. A fixture for holding elongated heated structural shapes of substantially uniform cross section `as suche'y shapes are subjected to a quenching action, said fixture being comprised of a pair of'platens of generally equal length longer than the length of the structural shape to be held, each platen being comprised of an elongated structural member rigid in both the horizontal and vertical directions transverse to its longitudinal length, a plurality of similar and equally spaced plates rigidly .fastened to said structural member and each having a plane perpendicular to the longitudinal length thereof, each plate having an edge extending transversely to the longitudinal `length of said member with the edges of each plate of each platen all being in a common plane, the plane of the edges of one platen being parallel to the plane of the edges of the other platen to define an elongated work piece receiving space of uniform thickness in both a longitudinal and transverse direction, the plates of one platen being spaced the same `distance apart and in the same transverse plane as the plates of the other platen, the edges of each plate having a plurality of spaced notches extending generally transversely to the plane of the plate and longitudinally of the platen, the notches of one plate of one platen being so spaced and arranged as to be offset from the notches of the opposed for forcefully bringing said platens into pressure engagement with a work piece positioned therebetween, a plurality of 4toggles pivotally mounted on one platen on longitudinally spaced transversely extending axes, each toggle including a frst arm mechanically connected to the other platen, and a second arm and power means interconnecting the second arm of each toggle for pivoting said toggles and I moving said platens into pressure engagement with a work piece, said plates being rigid in -a transverse direction and slightly flexible in a longitudinal direction, the edges of said plates between said notches being bevelled whereby said plates may flex slightly iny a longitudinal directlon to permit the work piece clamped between the edges to slip longitudinally relative thereto and contract as the work piece cools.

References Cited in the file of this patent UNITED STATES PATENTS 256,898 Jacobs Apr. 25, 1882 1,418,985 Stock June 6, 1922 1,444,258 Lothrop Feb. 6, 1923 2,608,752 Schilling Sept. 2, 1952 2,709,077 Allen May 24, 19755 FOREIGN PATENTS 667,961 Great Britain Mar. 12, 1952

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