US3431601A - Modular die - Google Patents

Description

March 11, 1969 w. L. LIPSCOMB MODULAR DIE Sheet File: Dec.

Fig. 2

INVEN'IUR. WILLIS L. LIPSCOMB IJY 541 & 34m

March 11, 1969 w. L. LIPSCOMB MODULAR DIE Filed Dec. 5, 1966 MO (16 .NS mm L L S L L Y U March 11, 1969 w, upsc 3,431,601

MODULAR DIE Fileci Dec. 5, 1966 1 Sheet of 5 !2 M W. 42 INVENTOR.

F WILLIS L. LIPSCOMB KImsJ-Cmw nited States Patent 3,431,601 MODULAR DIE Willis L. Lipscomb, 2208 Willow St, San Diego, Calif. 92106 Filed Dec. 5, 1966, Ser. No. 599,138 US. C]. 18-44 Int. Cl. B29c 1/06 7 Claims ABSTRACT OF THE DISCLOSURE Background of the invention The present invention relates to manufacturing techniques and specifically to a modular die adaptable to vacuum or pressure forming of plastics, injection molding, casting of plastics or metals, or other techniques in which material is formed over shaped elements.

Among the articles which are most suitable for forming with the modular die are light control louvers or panels of cellular construction, decorative panels, screens and the like, which have an overall pattern of raised or indented zones, either uniformly repetitive or somewhat randomly arranged. Such panels are normally made on large dies made in a single piece or in large sections of the particular pattern. Large dies are expensive to make and if a portion is damaged the entire die, or at least a large portion of the die, must be replaced. In addition, a large unitary die is impractical for a small number of panels due to cost.

Summary of the invention The modular die described herein is composed of individual shaped elements each conforming to a single feature, such as a cell, of a composite pattern. The elements are designed to interfit in a variety of arrangements on a rigid bed plate and are self-aligning in assembly. Only a few different types of elements are required to build up a large die, with finished edges and corners and a distinctive pattern over all or parts of the die. If a portion of the die is damaged or is required to be changed, individual elements may be removed and replaced without disturbing the remainder of the die.

Brief description of the drawings The basic die structure and various types of die elements are illustrated in the drawings, in which:

FIGURE 1 is a top plan view of a portion of a die, partly assembled;

FIGURE 2 is a sectional view taken on line 22 of FIGURE 1;

FIGURE 3 is a perspective view of a base die element;

FIGURE 4 is a perspective view of a corner die element;

FIGURE 5 is a perspective view of an edge die element;

FIGURE 6 is a perspective view of an insert die element;

FIGURE 7 is a sectional view of a portion of a panel formed on the die assembly of FIGURE 2;

FIGURE 8 is a sectional view similar to FIGURE 2, but with alternative insert elements at certain positions;

FIGURE 9 is a perspective view of an alternative insert element;

FIGURE 10 is a perspective view of a further alternative insert element;

FIGURE 11 is a top plan view of a hexagonal type die partially assembled;

FIGURE 12 is a sectional view taken on line 12-12 of FIGURE 11;

FIGURE 13 is a sectional view showing an alternative interfitting arrangement of die elements; and

FIGURE 14 is an enlarged sectional view, similar to a portion of FIGURE 2, showing the configuration of the elements to ensure close fitting and eliminate gaps.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawings.

Description of the preferred embodiments The die is assembled on a rigid bed plate 10 which forms the base and support for the complete die. In the simple configuration shown in FIGURES 1-6 the die is assembled to form a cellular panel with square cells in a uniform pattern. Four different types of die elements are all that are necessary to make up the die and these include a base element 12, a corner element 14, and edge element 16 and an insert element 18, shown in FIGURES 3, 4, 5 and 6, respectively. To facilitate accurate assembly all of the die elements have certain common dimensions which, in this instance are the dimensions of the square cells in the pattern. In the underside of each die element is a threaded socket 20, preferably at the geometric center of the common dimensioned portion for uniformity. Bed plate 10 has pro-drilled holes 22 spaced to correspond with the common dimensions of the die elements, that is, to align with threaded sockets 20 when the die elements are assembled in interfitting configuration, so that each element is held by a single screw 24. This uniformity allows the die elements to be assembled in a variety of different arrangements with complete accuracy of alignment and continuity of the pattern. However, other means of attachment may be used if necessary for special die arrangements.

Base element 12 has an upright box portion 26 of square configuration with a depressed cavity 28 conforming to a cell of the panel to be formed, and at the lower end of the box portion is a laterally extended, symmetrically circumferential base flange 30 also of square shape. Base flange 30 extends from each side of box portion 26 a distance equal to half the width of the box portion, so that when two base elements 12 are secured with their base flanges abutting, the space between the confronting sides of the box portions will be equal to the width of a box portion. The corners of base flange 30 have arcuate notches 34 and the center of each side of the flange has an arcuate notch 36, to provide clearance for screws 24 in the assembly.

Insert element 18 has a box portion 36 similar in size to box portion 26 and with a corresponding cavity 38, but no flange.

Edge element 16 has a box portion 40 with a cavity 42, also corresponding to box portion 26, but below one half of box portion 40 is a dropped base portion 44 equal in thickness to flange 30. Base portion 44- extends from one side of box portion 40 and is integral with a shoulder 46 along that side, the upper face of the shoulder being substantially coplanar with the bottom of cavity 42.

Corner element 14 is somewhat similar to edge element 16, having a corresponding box portion 48' and cavity 50, but the dropped base portion 52 and shoulder 54 extend around two adjacent sides forming the outer corner.

It should be noted that all of the box portions are of equal vertical height, so that the upper edges are in a common plane when assembled and correspond to the basic plane of the panel to be formed.

In assembly, the base elements 12 are secured in place first with their flanges 30 abutting, as in FIGURE 1, and provide a basic framework on which the remainder of the elements are assembled. This simplifies alignment and layout of any particular patterns which may be used. It will be seen that notches 32 and 34 combine to form clearance holes for screws in alignment with the bed plate holes 22. Corner elements 14 are then added at the corners of the assembly, the overall size of which is determined by the number of base elements used. The box portions 48 rest on the flanges 30 of the corner base elements when the dropped base portions -2 are pulled down by screws 24 to seat on bed plate 10. Next the edge elements 16 are added and also rest on base flanges 30 along the outer edges of the assembly. All intervening spaces are then filled with insert elements 18, each held by its own screw 24, to complete the cellular pattern. The relative positioning of the elements around a base element 12 is indicated in broken line in FIGURE 3. The shoulders 46 and 54 form a continuous shoulder surrounding the assembly which, in the formed panel 56 shown in FIGURE 7, provides an edge flange 58 coplanar with the bottoms of cells 60. If an accurate trimming guide is required a trim bar 62 may be fitted around the periphery of the die, as indicated in broken line in FIG- URES 1 and 2. Trim bar 62 has a bevelled edge 64 adjacent the shoulders 46 and 54 to form a shallow groove, into which the panel material is forced to provide a trim flange 66. This also prevents undue stretching of the panel material around the edges of the die.

The cellular cavities are by no means limited to the square form, even with the square configuration of the elements. In FIGURE 9, for example, an insert element 68 is shown with a hexagonal cavity 70, while FIGURE shows an insert element 72 with a cylindrical cavity 74. Either of these is interchangeable with insert elements 18 to provide variations in the pattern. Many different shapes can be incorporated into any or all of the die elements to form panels of various configurations. It is not necessary for all of the cells to be on one side of the basic plane of the panel. In FIGURE 8, for example, are shown insert elements 76 having raised portions 78, which would form cells on the opposite side of the panel from those formed in the adjacent cavities. Raised portions of various configurations can be incorporated into die elements other than the insert elements if required.

The die elements can have a basic planform shape other than square, as in FIGURES 11 and 12, in which the pattern is hexagonal. In this configuration, assembled on a bed plate 80, the die elements include a base element 82, a corner element 84, an insert element 86 and three types of edge elements 88, 90 and 92, which are necessary to complete the hexagonal pattern. Base element "82 has a hexagonal box portion 94 with a correspondingly shaped cavity 96 and a peripheral base flange 98, also hexagonal. At the center of each edge of base flange 98 is a semicircular notch 100 to provide clearance for retaining screws 102, which hold each element in place.

Insert element 86 is a simple hexagonal box containing a cavity 104 and corresponds to insert element 18. Edge element 88 has a half-hexagon box portion 106 with a corresponding cavity 108 and fits over the base flange 98 in the manner of edge element 16, an external shoulder 110 providing the edge flange of a formed panel.

Edge element 90 has a box portion 112 similar to portion 106, but includes a half-hexagon base flange 114 to fit between the base flanges of adjacent base elements 82. The outer edge of element 90 has a shoulder '116 to match shoulder 110.

Edge element 92 has a V-shaped base flange 118 to fit around a portion of base flange 98, and an upright wall 120 having a pair of V-shaped recesses 122 to receive portions of insert elements 86. Along the outside of wall and co-extensive therewith is a shoulder 124.

Corner element 84 is similar in many respects to edge element 92, having a base flange 126, wall portion 128 with recesses 130 and a shoulder 132, differing only in having a shoulder 134 continuing around one end.

As with the square configuration the hexagonal elements may be provided with a variety of cavity shapes or raised portions and arranged in different patterns. Triangular shapes are particularly adaptable to this configuration.

A simple form of the die, illustrated in FIGURE 13, uses base elements 136 which are similar to the box portions of base elements 12, but omitting the base flanges. These flangeless base elements 136 are secured directly on bed plate 10 in an alternating arrangement and the spaces are filled by insert elements 118. To facilitate assembly the base elements 136 are shown as converging slightly toward their upper ends, that is, the sides 138 are inclined inwardly and upwardly. The sides 140 of insert elements 18 are correspondingly inclined inwardly and downwardly. The taper need only be on the order of a few thousandths of an inch, merely enough to facilitate insertion of the insert elements between the secured base elements. Screws 24 will wedge the insert elements firmly in place between the base elements and seated on the bed plate. This simple form has one advantage over the flanged base element assembly, in that a small die can be made, not limited to the basic three units plus multiples of two necessary when the flanges must be accommodated. The tapered side configuration is adaptable to all forms of the die elements.

Since the die elements can be readily produced in quantity by casting or molding, it is desirable to minimize tolerance requirements. The most critical fit in the assembled die occurs at the upper edges of the box portions, where gaps between adjacent elements would cause corresponding ridges in the formed panels. To ensure close fitting without impractical manufacturing precision, the die elements may be made as shown in FIGURE 14, which use base elements 12 and insert elements 18 as examples, although the configuration is applicable to all die elements. Insert element 1 8 has the tapered sides 140, as shown in FIGURE 13, while the base elements 12 have correspondingly tapered sides 142. At the upper edges of sides 140 the taper is increased so that the upper edges of box portion 36 have widened portions 144. Similarly, at the upper edges of sides 142 the taper is decreased to provide widened portions 146. The widening is on the order of one or two thousandths of an inch in each case, merely enough to ensure a tight fit. Since the widening occurs around the edges of cavities the die elements will normally accommodate any very slight distortion occurring by the tight fitting, without affecting the formed panel. The technique of laying out an initial framework of base elements ensures uniformity throughout the die, and eliminates the possibility of progressive or accumulative misalignment or error which could occur if the elements were merely assembled in rows across the die.

As illustrated the basic die is suitable for vacuum or pressure forming of sheet material, or for pressing into deformable material. By adding barriers or walls around the die a panel could be made by pouring in liquid material which can be hardened. Further, the die can be adapted to injection molding by securing a plate over the die at the required spacing, or even by using a complementary die built up in the same manner and dimensioned to provide the necessary wall thickness in the panel. All the techniques are well known and are mentioned to indicate the adaptability of the modular die construction.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and

that the specification and drawings are to be considered as merely illustrative rather than limiting.

I claim:

1. A modular die, comprising:

a rigid bed plate;

a plurality of die elements each incorporating a specific shaped portion of the die and being individually secured to said bed plate, said die elements interfitting closely in abutting relation and forming a composite die structure;

said die elements including (a) base elements adapted for initial securement to the bed plate in a predetermined overall pattern, thereby providing a basic fixed framework for the die and preventing accumulative error across the composite die during the assembly thereof; and

(b) insert elements secured between said base elements.

2. The structure according to claim 1 and further including edge elements interfitting with said base and insert elements along at least portions of the die, said edge elements having edge forming portions abutting in continuous relation.

3. The structure according to claim 2 and further including corner elements interfitting with said base and insert elements at corners of the composite die, said corner elements having edge forming portions continuous with the corresponding portions of said edge elements.

4. The structure according to claim 1, wherein said base elements have base flanges extending from the lower portions thereof, the base flanges of adjacent base elements abutting and spacing the base elements apart at the correct distance to receive said insert elements in close fitting inter-relation, and said insert elements resting on said flanges.

5. The structure according to claim 4 and further including edge elements partially overlapping said base flanges along the edges of the die, said edge elements having dropped portions externally of and equal in thickness to said base flanges, whereby the edge elements rest on the base flanges and said bed plate.

6. The structure according to claim 1, wherein the outer sides of said base elements converge upwardly from said bed plate, the outer sides of said insert element being correspondingly divergent, whereby the insert elements fit in tightly wedging relation between the base elements.

7. The structure according to claim 6, wherein at least portions of the upper peripheries of said base elements and insert elements are outwardly thickened to bind tightly against each other when assembled.

References Cited UNITED STATES PATENTS 2,443,826 6/1948 Johnson l844 X 2,715,752 8/1955 Hunter l844 X 3,061,880 11/1962 Weisbach l844X 3,360,829 1/1968 Germ 18-42 J. SPENCER OVERHOLSER, Primary Examiner. J. H. FLINT, JR., Assistant Examiner.

US. Cl. X.R. 249-l17,

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