US3543315A

US3543315A - Soft board fabrication

Info

Publication number: US3543315A
Authority: US
Inventors: William L Hoffman
Original assignee: WILLIAM L HOFFMAN
Current assignee: WILLIAM L HOFFMAN
Priority date: 1967-10-09
Filing date: 1967-10-09
Publication date: 1970-12-01
Anticipated expiration: 1987-12-01

Description

Dec. 1, 1970 w, HOFFMAN 3,543,315

SOFT BOARD FABRICATION Filed 0G13. 9, 1967 FIG. 6.

A INVENTOR. h//u/AM L. HOFF/v4 United States Patent O 3,543,315 SOFT BOARD FABRICATION William L. Hoffman, 16646 Linda Terrace, Pacific Palisades, Calif. 90272 Filed Oct. 9, 1967, Ser. No. 673,806 Int. Cl. A63c 7 5 00 U.S. Cl. 9--310 2 Claims ABSTRACT OF THE DISCLOSURE A surfboard fabrication providing increased safety insofar as the usual hard surfacing thereof is virtually elimiuated. Specifically, a Surfboard is fabricated with a low density core contoured to the required depth and carrying spaced stress members, and over which a skin of depressible material is carried for supporting engagement of a persons body parts, for example. Broadly, this invention is applicable to any board, plank, platform, panel or like article, where safety as related to the elimination of hard surfaces is required.

Surfboards and like planar articles are ordinarily characterized by their presentation of hard supporting surfaces. For example, ordinary surfboards are very dangerous in this respect and have been the cause of a great many serious injuries to those persons using the Same. It is the rock-hard surfacing of Such boards which is fundamentally dangerous, when coupled with the tremendous hydraulic forces that can be compounded when out of control in a pounding surf or waves. It is also the substantial inertia of the Surfboard body coupled with the lightness of construction which affords large surface areas for the hydraulic effects of wave motions, together with the presence of acutely rounded and/or sharpened edges and pointed ends. However, the usual and accepted configuration of a Surfboard cannot be disturbed in that its capabilities for its intended use depends upon the length, width and depth ratios as they are related to the camber, sheer and body lines or contours. Therefore, the usual and accepted Surfboard configuration is to be maintained, and the present invention permits said maintenance with the underlying fabrication of an entirely new and distinct concept which involves light weight, mechanical strength and Surface softness entirely throughout the board.

Usual surfboards are characterized by hard and slick surfaces which must be treated inone way or another as a compromise so as to prevent a persons slipping thereon. That is, the usual construction involves a hard surface skin which must be roughened or coated with some antiskid substance. With the present invention, however, it is an object to provide a natural foot and/or hand hold by means of a somewhat depressible surface that normally retains the dynamic contours required of the Surfboard. That is, it is a depressible skin which supports the body of the person, the hands and feet and any other parts, the skin being of a resilient substance or any material having memory that will return to its originally intended shape, Therefore, the said skin is of substantial thickness and of sufficient density so as to have consequential depressive action accompanied by mechanical strength.

It is an object of this invention to provide a method of fabricating a board having the distinctive qualities hereinabove referred to and which has manufacturing feasibility coupled with commercial practicality. With the fabrication method hereinafter described, the specified materials and their Structural relationships in the finished article are subjected to a treatment whereby a rigid structural member is encapsulated within a depressible skin without surface blemishes, whereby a finished Surfboard is extractible from a mold.

ICC

The various objects and features of this invention will be fully understood from the following detailed description of the typical preferred form and application thcreof, throughout which description reference is made to the accompanying drawings, in which:

FIG. l is a perspective View of a Surfboard embodying the present invention. FIG. 2 is a longitudinal sectional view taken as indicated by line 2-2 on FIG. 1. FIG. 3 is a transverse section of the Surfboard as it is formed in a mold. FIG. 4 is an enlarged detailed sectional view taken as indicated by line 4-4 on FIG. 3. FIG. 5 is a detailed section taken as indicated by line 5-5 on FIG. 4, and FIG. 6` is a view of the compacted and preferred filler member prior to its extension and connection to cap members.

The board fabricated in accordance with the present invention is referred to as a softboard, in that the surface thereof is not in any way hard. The board herein referred to is specifically an aquatic Surfboard, but broadly is an article of manufacture like a plank, a platform or any such panel-like article. Further, the invention is not to be limited to softness at one side of such a board, but both sides and entirely therearound, which includes top, bottom, opposite edges and opposite ends, or the comparble parts of rounded articles. However, it is a Surfboard whic his particularly well suited to this board fabrication, such as the Surfboard B shown in FIG. 1 and which involves generally, a rigid core C, an encapsulating skin S, and a skeg G. The core C is the structural element that gives the board B its cross-sectional body and longitudinal sheer, and overall rigidity, while the skin S is the non- Structural element that gives the board B its softness and encapsulating feature that protects the core C from danger and reversely from causing danger and/or bodily injury to a person who might be struck by the board. Further, there is the skin S which is depressible for the enhancement of traction without resort to the usual anti-skid features.

The structural member of the Surfboard B is the core C fashioned tothe general configuration required of the board and characterized by its inward dimensional offset a of a nominal 1/2 inch, for example. The core C is primarily a lightweight frame presenting an imperforate space occupying form to which the external skin S is attached. Accordingly, the core C need not present a precisely offset a contour, since it is the superimposed skin S which presents an exterior wall or Surface that establishes the precise outside configuration of the Surfboard. A feature of this invention is, therefore, that the core C can be advantageously constructed without resort to compound curvatures, thereby increasing the structural capability of the core C in its function as a beam or frame. Thus, the skin S varies in depth or thickness as it coextensively encapsulates the core C, being permanently adhered to the core to be held in a fixed disposition for the establishment of a permanent and precise board configuration. In practice, the skin S is molded around and onto the frame-like core C, it being preferred to employ a substantially waterproof material as the body of skin S, that is, a material which is impervious to and/or does not become water soaked.

The present invention provides a method of fabrication whereby a substantially rigid frame member or core C is encapsulated within a protective and protecting skin S. The core C, as it will be hereinafter described, is a lightweight Structural member having the general shape of the Surfboard B, no attempt being made therein to establish the precise sheer line as seen from the side, or to establish the precise camber of the deck or rocker of the bottom as seen from a transverse cross section. Consequently, the core C is smaller in configuration than the finished Surfboard B, but substantially coextensive with the configuration of the surfboard. As shown, a typical core C is of variable rectangular cross section and of tapered plan configuration, and is characterized by an arcuate sheer line variable between the top and bottom. Specifically, the transverse cross section throughout the core C presents a straight transversely disposed top and bottom 11, the longitudinal concavity of the former being greater than the convexity of the latter, whereby the forebody F and afterbody A are tapered as viewed from the side. In plan view, the said forebody F is tapered forwardly while the said afterbody A is tapered rearwardly, there being a mid-section D having straight and preferably parallel sides 12 continuous with the fore and aft bodies. In practice, the front and back are truncated

fiats

13 and 14, and in accordance with the invention the top 10, bottom 11, sides 12 and

fiats

13 and 14 are each imperforate so as to establish a male form simulating the general contours of the Surfboard B.

As illustrated, in practicing the method of this fabrication there is a mold M comprised of separable female sections mated together along a median sheer plane b that is coextensive of the Surfboard to be molded therein. In practice, the sheer plane b follows the maximum half- 'breadths of the Surfboard contours, being the parting line of the mold, and which thereby circumscribes and/ or embraces the mold and board to be processed therein. It is to be understood that the precise Surfboard contours are established in the mold M, including the sheer and crosssectional camber and rocker, and further establishing the rounded sides and ends, all of which involves the necessary variations in the dimensional offset a which establishes the thickness of skin S.

In carrying out the method of this fabrication, the core C in the form described generally above is placed within the mold M and held in spaced relation to the inner walls of the mold by means of spacers 15 that establish the dimensional offset a. at each point of placement thereof. The spacers 15 can vary in shape and are preferably tapered pyramidal conical forms having a widened base 16 for flat supporting engagement upon the top 10 and bottom 11 of the core C, and with the sides 12 if so desired; and for locating engagement against the inner surface of the mold M, where circumstances require. It is the apex 17 of the spacer 15, or the truncated top thereof, that touchingly engages the surface of the mold so as to space the core therefrom. The base 16 of the spacers, strategically positioned as indicated, are cemented to the core for reliable positioning, and in accordance with the invention the spacers are formed of the same material as the skin S, or a substance compatible therewith. In practice the skin material can be polyurethane foam that is supplied into the mold M to surround the core C and spacers 15 and to solidify therein. Therefore, it is preferred to form the spacers 15 of polyurethane, of the same properties as the skin, and to which the molded skin S will fuse and/or adhere. Thus, the spacers will have the same physical properties as the skin and will be relatively undetectable. Further, and in order to provide a water impervious surface over the polyurethane skin S, the cavity Walls of the mold M are precoated with a film of vinyl plastic, or the like, and which adheres onto and transfers to the body of polyurethane that is supplied into the mold to surround the core C.

The skin S is injected or otherwise pumped into and/ or placed in the mold M in a fluid state to occupy the entire mold chamber surrounding the core C and t0 fill into and between all interstices which occur. For example, a usual appendage and modification 0f a surfboard B is a removable skeg G and which involves a chest 20 adapted to receive and mount the skeg 21 per se. In accordance with the invention the chest is molded of a plastic such as polypropylene and has a depth corresponding to the dimensional offset n plus the depth of the core C, along the bottom 11 of afterbody A and like the spacers 15 is held or otherwise fastened or cemented into a slotted opening in the bottom 11 and thereafter molded to the skin S, all without disturbing the top 10. The substance or material of skin S can vary as circumstances require and is selected to have a cushioning property, being somewhat depressible and having resilience. Such a material is polyurethane that is foamed so as to have a resilient cellular structure, and with the characteristic of adhering to other materials, such as to the core C, and of developing a surface skin that is substantially impervious to water. In practice, water will penetrate or be saturated into the surface of said polyurethane having a skin, but only slightly and to an insignicant extent. It is to be understood that other cushioning materials can be molded onto the core C, such as rubber or the like, polyfoams including urethanes, ethafoams, polyvinyl foams or any flexible or semi-flexible foam materials of reasonably light weight and solid character, or for example cellulose foams or any similar and/or suitable synthetic or natural cushioning materials.

Referring specifically to the core C, said core in its preferred form is fabricated of a filler 25 and top and

bottom caps

26 and 27 attached thereto. The core C being a frame-like and rigid structure, the filler 25 is suitably shaped and/or otherwise contoured so as to have the core configuration hereinabove described, and the

caps

26 and 27 are secured to the filler so that the core will maintain its formation. Mainly therefore, it iS necessary that the filler have sufficient vertical strength so as to resist stretch and compression, to thereby hold the

caps

26 and 27 in the established spaced relation. Secondly, and equally important, it is necessary that the caps have sufficient planar strength so as to resist both compression and tension. As shown, the filler 25 is of rectangular cross sectional configuration and the

caps

26 and 27 are sheet material of simple fore and aft curvatures so as to establish the top and bottom sheer lines of the core. The filler 25 is of low density, any suitable material such as a foamed or extruded plastic or metal, with the establishment of side walls at 12.

In accordance with the preferred form of the invention, the filler 25 of core C is a collapsible fabrication of phenolic impregnated paper adapted to be extended into vertically disposed and adjacently attached hexagonal tubular columns, commonly referred to as honeycomb And, the

caps

26 and 27 are thin coextensively wide and imperforate sheets of aluminum, for example, and which are warped into position on the filler and adhered thereto by suitable adhesive. Thus, with the said honeycomb filler 25 extended and the

caps

26 and 27 warped thereon and adhered thereto, a stiff and substantially infiexible box beam is the result.

A feature of this fabrication is the method of producing the filler 25, which comprises collapsing the filler into a solid stack of phenolic impregnated paper, the previously manufactured and completed honeycomb, and machining and/or suitably shaping the same by removing three dimensional solid areas therefrom. In the drawings are shown planar cuts whereby the resulting extended and finished structure is a box-beam of fiat sided configuration. It is to be understood, that simple curvatures can be formed top and bottom and compounded at the sides and ends. Thus, the

caps

26 and 27 are stressed skin elements affording great strength in the box-beam construction of the core C. In carrying out the invention, the phenolic impregnated paper filler 25 is coated with adhesive substrates, and likewise are the surfaces of the

caps

26 and 27, whereby the filler and caps are coextensively attached one to the other with the application of additional adhesive and/or suitable bonding agents.

From the foregoing it will be seen that the board fabrication hereinabove set forth is for a soft board as distinguished from a hard board, the patentable method and article residing in interdependent steps on the one hand and cooperative structure on the other hand. However, it will be observed that there are various methods by which the surfboard B can be produced and that the novel method herein disclosed is the preferred method of producing the same. The resulting article is, in either case, a soft surfaced and cushioned board and which is inherently safer by far than the usual hard surfaced boards. A distinct advantage is the unobvious superior foothold, hand or knee hold afforded by virtue of the depressible property of the board. In practice, the useable trend surface of the Surfboard B is textured at 30 so that it is not slick, and with the application of body weight the foot, hand, knee or any other body part depresses into the surface of the board, below the normal mold line, and creates an indentation that tends to anchor the persons body part at and/or within the depression made thereby. Therefore, there is a restrictive action against planar movement or displacement and a natural requirement for lifting the body parts out of the anchoring depressions. However, with the discriminate selection of material depressibility, it is possible to have sufficient surface stiffness Without undue and/or hindering softness, all as may be required by the experience and requirements of the surfboard users.

In practicing this invention, the skeg chest 20 can be captured and suitably located in the mold so as to support and carry the core C in cantilevered fashion in which case the forebody F of the core can be positioned with a minimum application of spacers 15 or equivalent positioning means. Further, the flat sides 12 covered by the generously thick body of skin S affords an effective bump-rail surrounding the board B, while the body form of the nose and tail can be backed by suitable nose and tail blocks 31 and 32 that extend from the truncated ends 13 and 14. The finished board B can be fabricated to weight specifications as required, and the polyurethane skin S having a surface subject to slight water penetration thereby presents a water to Water antifriction property that enhances operation of the board.

Having described my invention, I claim:

1. A soft surface Surfboard including, a rigid elongated low density male core having an imperforate exterior and in the form of a frame comprised of top and bottom cap members held in spaced relation by a three dimensional filler of adjacent columnar tube disposed substantially normal to the said cap members, and having sides, and having a skeg chest embedded therein and projecting therefrom, and a depressible skin coextensive of the core and bonded thereto and to and around said skeg chest and held thereby in the configuration of the core so that the board has overall surface softness with acess to said skeg chest, and wherein the skeg chest bears against the said top cap and through the ller and projects from an opening in the botom cap member.

2. The soft surface Surfboard as set forth in claim 1 and wherein, the top and bottom cap members are of sheet aluminum and the three dimensional filler is of phenolic impregnated paper having adjacently attached hexagonal columnar tubes disposed substantially normal to the said cap member.

References Cited UNITED STATES PATENTS 2,794,756 6/ 1957 Leverenz 161-43 2,858,580 11/1958 Thompson et al. 2,926,363 3/ 1960 Madlem 9-6 3,137,873 6/ 1964 Garrolini 9-310 3,145,400 8/1964 Yoakurn 9-310 3,224,924 12/1965 Von Ardenne et al. 16l-68 3,276,050 10/ 1966 Edwards 9-310 3,323,154 6/1967 Lambach 9-310 3,414,919 12/1968 Gust 9-310 3,067,507 12/1962 Titus. 3,072,225 1/ 1963 Cremer et al.

FOREIGN PATENTS 961,612 6/1964 Great Britain.

MILTON BUCHLER, Primary Examiner P. E. SAUBERER, Assistant Examiner U.S. Cl. X.R. 9-6; 161-68, 161

Disclaimer 3,543,315.-WZlz`am L. H omcm, Pacific Palisads, Calif. SOFT BOARD FABRICATION. Patent dated Dec. 1, 1970. Disclaimer filed Jan. 21, 1974, by the inventor. Hereby enters this disclaimer to all claims of said patent.

[Ocz'al Gazette 00150561I 15, 1.974.]