US2823726A - Hand press with die bracing structure - Google Patents

Description

Feb. 18, 1958 F. WAGNER 1 2,823,726

I HAND PRESS WITH DIE BRACING STRUCTURE Filed April 19, 1954 2 Sheets-Sheet 1 IN V EN TOR. FHA IVK W4 GNE R 5" Maw A T TORNE Y Feb. 18, 1958 F. WAGNER 2,823, 26

HAND PRESS WITH DIE BRACING STRUCTURE Filed April 19, 1954 2 SheetsSheet 2 A T TOR/V5 V racies due to these factors.

HAND PRESS WITH DIE BRACING STRUCTURE Frank Wagner, San Gabriel, Calif.

Application April 19, 1954, Serial No. 424,039

1 Claim. (Cl. 153-21) The invention relates to hand presses and particularly to means for maintaining the alignment of dies in hand presses.

The invention is concerned with hand presses of the type used by die makers for precision forming. Such presses are used in forming narrow strips of sheet steel or steel rule into punch dies for cutting out objects from material such as sheet cork or cardboard. Gaskets, cardboard cartons and dividers, and other like objects are punched out by steel rule dies which are usually closed polygons.

A conventional hand press consists basically of a base having a slidable carriage, a lever to move the carriage back and forth in the base, and means for mounting various forming dies to the base and carriage so that the dies may be brought together under considerable pressure by movement of the carriage.

In operation, a length of steel rule is placed between the forming dies so that its bottom edge rests on the level bed of the press while the forming procedure is carried out. If the vertical relationship between the press bed and the die faces is not maintained, a steel figure will result which is off its feet, i. e., whose bottom edge is not coplanar for its entire length.

Lack of true vertical relationship between the press bed and the die faces results from several factors. die mounts wear and allow the dies to tilt. The dies themselves may wear. thrust of the carriage to the second, or fixed, die with sufiicient force to displace the top portion of the die, distorting the desired bend line. As the carriage movement forces the dies together the dies seat against the back surfaces of their respective mounts. or dies have worn to any extent, continued carriage pressure tilts the static die from the desired verticality.

The hand press of the invention overcomes the inaccu- It includes a base, a carriage that is slidably mounted in the base and a lever adapted to reciprocate the carriage in the base. dies are removably mounted, one to the base and one to the carriage. A first clevis is fixed to the base remote from the carriage and a second clevis is fixed to the carriage remote from the die located in the carriage. A separate adjustable horizontal locator is held in each of the clevises, with an outer end of the respective locators in contact with the dies supported in the base and carriage.

The horizontal locators index against the upper portions of the dies away from the die faces and also brace these upper portions against the carriage thrust.

The locators may be adjusted horizontally by mounting them on transverse eccentric shafts journalled in the clevises. This permits the die maker to align the die faces to exact verticality with respect to the press bed at the point where the dies reach the final bending position. (This is at the extreme of the carriage travel allowable for the thickness of the material being formed.) At the final bending position the dies are thrust against The Hardened steel transmits the If the mounts A pair of mating 2,823,726 Patented Feb. 18, 1958 2 their respective mounts, and may or may not be vertically aligned. Each locator is then adjusted horizontally so that it braces the upper portion of the die in the position that gives the die face true verticality with. respect to the press bed.

To eliminate one of the wearing surfaces contributing to die inaccuracy, the preferred embodiment of the invention utilizes a unique means of die mounting Conventional hand presses have die mounts which. fit into recesses in the press base and carriage, and in turn have dovetail grooves for receiving the die proper.

The dies of the preferred embodiment have integral tangs depending from. each die. Each tang has one horizontal dimension smaller than the comparable dimension of the die body. These tangs are an exact fit for recesses formed in the upper surfaces of both the press bed and the carriage.

Use of these dies is made possible by the bracing action of the horizontal locator of the invention, which eliminates the need for heavy die mounts, enabling the dies themselves to be located directly in the press bed and carriage.

These and other advantages of the invention are ex-. plained more fully in the following detailed specification. and drawing in which- Fig. 1 is a perspective view of a preferred embodiment of the invention;

Fig. 2 is a sectional elevation taken along the longitudinal center line of the embodiment of Fig. 1;

Fig. 3 is a transverse sectional elevation taken along:

line 33 of Fig. 2;

Fig. 4 is an exploded perspective view of the preferred die mounting method;

and Fig. 6 and Fig. 7 are elevations of a radiusing die in accordance with the invention.

Figs. 1 and 2 illustrate the primary elements of the.

preferred hand press of the invention. A press base 10 of substantially conventional configuration rests on front;

and rear legs 11, 12. A carriage 13 slides in ways 14, 15

formed by L- shaped side rails 16, 17 fastened by countersunk screws to a first recessed portion 18 of the basetop.

A clevis 20 projects vertically from the rear portion; projects vertically;

of the carriage. A similar clevis 21 from the front portion of the base.

Clevis 20 supports an eccentric adjusting shaft 22 trans- A horizontally extending. die locator 23 is pivotally mounted on the adjusting shaft. so that it extends from the clevis toward the center of the. base. A helical locator return spring 24 is positioned. around the shaft and has one downwardly extending arm 25 held in a hole in the clevis, and one horizontal arm 26,-.

versely of the carriage travel.

bent over the top of locator 23. The spring loads the locator 23 against displacement away from the carriage.

bed.

28, a die locator 29, and a spring 30.

A second recessed portion 31 of the base holds a hardfl ened steel die mount 32. A die 33, which is one of a} Fig. 5 is a plan section taken along line 55 of Fig. 2;;

In similar fashion, clevis 21 holds an adjusting shaft;

3 machined to present a true surface to register against respective ends 37, 38 of locators 23, 29.

A rod 40 projects from one side of the press base and a conventional machinists square 41 is pivotably mounted on the outboard end of the rod so that the ruler 42 of the square runs in a line that is transverse of the press. The ruler is used to determine the position for the bends in the steel strip being formed in the press.

The carriage 13 reciprocates in the ways in response to movement of a lever arm 43 to which it is coupled by a link 44 journalled at one end on a first pin 45 in the carriage and at its other end on a second pin 46 fixed in a forked extension 47 of the lever arm. A pivot 48 through the lever arm back of the extension is held by a pair of spaced wings 49, 50 projecting upwardly from a sloping upper surface 51 of the rear leg 12 of the press base. A notch 52 in the rear of the carriage provides clearance for movement of the link 44.

The forward movement of the carriage is stopped by the die block 32, but the various thicknesses of materials processed require additional travel limiting means. Without a travel control, a set of dies would have to be made to accommodate each metal thickness by varying the distance from the die face to the forward edge of the die tang. Therefore the preferred embodiment of the invention provides a travel control means with a wide range of variation. The control means comprises a control arm 55 pivotably fastened at an end 56 to an extension of the carriage pin 45. An elongated opening 57 near the opposite end 58 fits around a projection of the lever arm pivot 48. A long screw 59 passes through a tapped hole and projects into the elongated opening. Any increase in the distance that the screw projects into the opening decreases the length of carriage travel, since the end of the screw butts against the pivot projection when forward movement of the carriage toward the center of the base pulls the travel control in that direction. A locking nut 60 on the external portion of the screw fixes the position of the screw after the desired adjustment is made.

Figs. 3, 4 and 5 illustrate in more detail the construction of the preferred hand press.

Clevis 20 is shown in enlarged horizontal section in Fig. 5. Adjusting shaft 22 holds locator 23 at its most rearward position. Arms 61, 62 of clevis 20 are slotted horizontally at the point Where they journal the shaft. Screws 63, 64 threaded into the bottom faces of slots 65, 66 bind the clevis arms about the shaft when the screws are tightened. A squared end 67 on the shaft provides means for rotating the shaft and adjusting the locator when the screws are loosened.

The locator has an enlarged end 68 to accommodate a bore 69 which fits an eccentric portion 70 of the adjusting shaft. A groove 71 in the side of the enlarged end houses the locator return spring 24 and provides a channel for spring arm 26. Clevis assembly 21 is identical to clevis assembly 24), which has been described in detail with reference to Fig. 5.

When the locators are lifted to change dies, the springs return them to indexing position. In Fig. 3 locator 29 is in indexing position against die 33 in the base. The die in the carriage is broken away to show die 33. A tang 72 of carriage die 34 projects into a recess 73 in hardened block 35 that is fastened to a horizontal lip 74 on the carriage. The configuration of the block is a continuation of the carriage configuration so that the block and carriage move in ways 14, 15 as an integral unit.

In order to seat the die above the bed of the carriage and base, one horizontal dimension of the die body must exceed the comparable dimension of the tang. Thus, as illustrated in Fig. 4, die 34 has a body portion 77 that exceeds the longitudinal dimension of the tang 72, while a radiusing die 80, shown in Figs. 6 and 7 has a body portion 81 that exceeds the transverse dimension of a tang 82.

The tangs of dies 34, 80 conform to the vertical surfaces of the recess in block 35. The mating die of each pair (not shown) has a tang that conforms to the recess in the die mount in the base. For uniformity in manufacture, the recesses are alike in dimension and shape, but need not be so.

Dies to impart a wide range of configurations to the sheet steel stock can be used in this press. More acute bends than a conventional press can handle may be done on the press of the invention because it permits use of less bulky dies and affords clearance behind the dies.

The accessibility of its travel control and the measuring ease provided make it a tool that speeds the production of steel rule products.

I claim:

A hand press comprising a base, a carriage slidable along a portion of the base, lever means adapted to reciprocate the carriage, a first die mount immovably supported on the base, a second die mount mounted on the carriage to reciprocate therewith, first and second dies mounted respectively in and projecting from the first and second die mounts in mating relation when the second die mount is moved into proximity with the first die mount by reciprocation of the carriage, a first clevis immovably supported on the base in fixed spatial relation to and outwardly of the first die mount on the side thereof opposite the carriage, a second clevis mounted on the carriage in fixed spatial relation to and outwardly of the second die mount on the side thereof opposite the first die mount so as to move with the carriage, a first die locating member held in the first clevis and extending inwardly therefrom to engage and brace the first die at a point spaced from the first die mount, a second die locating member held in the second clevis and extending inwardly therefrom to engage and brace the second die at a point spaced from the second die mount, adjustable means mounting each die locating member in its respective clevis operable to adjust the position of the respective die locating member and thereby provide an adjustment of the respective die, said adjustable means comprising a shaft rotatably mounted horizontally in the respective clevis and transversely of the extension of the respective die locating member, the shaft having an enlarged cylindrical section within the clevis eccentric to the shaft axis and about which the die locating member is rotatably supported whereby rotation of the shaft within the clevis results in a linear displacement of the die locating member.

References Cited in the file of this patent UNITED STATES PATENTS 1,170,227 Eaton Feb. 1, 1916 1,478,443 Lorch Dec. 25, 1923 2,277,360 Wagner Mar. 24, 1942

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