US 3619833 A
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Description (OCR text may contain errors)
2 Sheets-Shoot 1 PLASTIC RAFT E. J. KELLER Nov. 16, 1971 Filed May 13, 1969 Nov. 16, 1971 E. J. KELLER 3,619,833
PLASTIC RAFT Filed May 13, 1969 2 Sheets-Shoot B HTTORNEYS United States Patent Office 3,619,833 Patented Nov. 16, 1971 3,619,833 PLASTIC RAFT Ervin J. Keller, G-4382 Lippincott, Flint, Mich. 48507 Filed May 13, 1969, Ser. No. 824,101 Int. Cl. B63c 9/ 04 U.S. Cl. 9-11 8 Claims ABSTRACT OF THE DISCLOSURE A lightweight plastic raft including a top support surface with a dependent rigid foam plastic ring side providmg flotation and defining a central air chamber. Slightly spaced, segment shaped, rigid cores are provided for the top joined by the fibre glass resin composition with which the top is coated. A valve communicates the air chamber with atmosphere and permits the raft to be vacuum locked to the water.
One of the prime objects of the invention is to provide a lightweight raft of attractive and pleasing appearance which is relatively economical to fabricate and requires no malntamence.
Another object of the invention is to provide a strong and durable raft of the character described which can be readily installed and removed from installed position.
A further object of the invention is to provide a raft of the character described which may be locked in a position of adjusted height in the water and at the same time locked in a stabilized position which prevents tipping.
Still another object of the invention is to design a selfdraining raft having an upper surface configured so that it is comfortable for sun bathing but at the same time provides a non-slip surface when wet.
Another object of the invention is to provide a raft which avoids any problems with bathing suits snagging or slivers.
Other objects and advantages of the invention will become readily apparent when considered with the attached description and with the accompanying drawings.
Briefly, in its broad aspect the invention is concerned with a fibre glass raft including segmented cores and having a wall side formed `by a otation providing member.
In the drawings:
FIG. 1 is a perspective plan view of my raft;
FIG. 2 is a top plan view thereof;
FIG. 3 is a partly sectional, side elevational View;
FIG. 4 is an under plan view with a portion partially broken away to expose the interior construction thereof;
FIG. 5 is a considerably enlarged, fragmentary, sectional elevational view taken on the line 5 5 of FIG. 2;
FIG. 6 is a fragmentary, enlarged plan view illustrating the configuration of the tread surface; and
FIG. 7 is a sectional elevational view thereof.
Referring now more particularly to the accompanying drawings, a letter 10 generally designates a raft which as shown is circular in form and comprises a slightly pitched upper surface or top generally designated lil supported on a dependent side wall 12 formed by a ring (see FIG. 3) of rigid polyurethane foam. The foam ring 12 provides adequate buoyance when the raft is in the water to support swimmers with a total weight in the neighborhood of 2500 lbs. if need be, and marginally defines a closed space or chamber 13 between the water 1'4 and the top or support surface 1.1.
As FIGS. 1 and 2 particularly indicate, the surface of the raft top 11 is configured to pie-shaped sections .'15 separated by narrow smooth surfaced portions 16 which at their radially inner ends merge into a smooth surfaced circular central portion 17. The pie-shaped sections are provided with a tread surface, as shown at I15, and it is to be understood that this tread surface 15' is provided in exactly the same manner on each pie-shaped segment 15. 'Further it will be noted that the tread surface 15 extends to a rounded peripheral edge portion 18' which joins the top 11 with the outer peripheral surface of the ring 12. The tread surface consists of parallel grooves x and y with mounds m between them having fiatted off central portions z.
The construction of the raft perhaps can best be understood from an inspection of FIGS. 4 and 5. It should be understood that the raft is formed in a female mold, and the surface configuration of the mold forms the tread portions 15 and the portions 116, 17 and 18. In forming the raft a polyester gel coat 19 (see FIG. 5) in the nature of .G12-.020 in thickness is first sprayed into the mold cavity and forms the outer exterior surface of the top 1^1 and side 12. Then a fibre glass and resin layer 20` approximately 1/s in thickness is sprayed into the cavity and forms an immediately underneath layer. The resin may be a suitable commercial polyester with a setting catalyst. The next step involves inserting pie-shaped plywood pieces about 3A in thickness in the mold to form rigid core sections. As FIG, 4 indicates the pie-shaped plywood members 21 are disposed in slightly spaced apart relationship as at 22, and do not fully meet at their radially inner ends. The segment members 21 may extend radially inwardly about the same distance as do the portions 15 shown in FIGS. 1 and 2 and, in fact, may be the same shape as the portions -15 shown in FIG. 2.
The inner ends of the plywood segments 21 are joined together by a plywood block 22 about 3%1 in thickness which is simply laid over them. Then finally a finish fibre glass resin coating 22a about 1/16 in thickness is sprayed over the interior of the raft and when set anchors the block 22 to the segments 21 to provide a unitary core structure. The spaces between segments 21 do not completely fill with resin and grooves 2211 remain. Because the pie-shaped plywood sections 21 do not extend all the way to the center of the raft a space 23 is left between them (see FIG. 5), and this space accommodates a nut 24 which secures an eye bolt `25 in position. The eye bolt 25 forms a ring to which an anchor chain may be secured in any suitable manner.
The space 23 also provides a passage communicatmg with an opening 26 extending through coatings 19, 20 and 22a and block 22. A normally closed conventional, depressible stem, tire valve 27 selectively communicates the air chamber or space 13 with the exterior atmosphere. The valve may be a conventional Shrader valve of the type used on vehicle tires or could be any other suitable valve. The opening 26 is preferably of a size to snugly receive the valve 27 which preferably is slightly recessed in the opening 26 so that the accessible, depressible stem thereof lies slightly below the surface 17 of the raft.
The plywood segments 21 are slightly spaced apart as at 22 because it is highly desirable to provide a crown or slope to the supper surface 11 of the raft to permlt water to drain off. It would not be possible to provide such a crown with a circular core.
Once the raft is formed and placed in the water as shown in FIG. 3, it may be vacuum locked in position in a manner in which will now be described. The top of the raft is loaded as, for example, by placing sand bags on it to cause it to sink lower into the water, and this has the effect of compressing the air in chamber 13 so that it now assumes a pressure greater than atmospheric pressure. If the stem of the valve 27 is now depressed by a person sitting on the raft, air may be evacuated from the chamber 13 to the desired degree. rlfhen, when the sand bags or other weights are removed, the raft raises in accordance with the amount of air which has been removed so that the air in chamber 13 is now below atmospheric pressure and the raft accordingly is vacuum locked in position. The height of the raft in the water may be varied with the amount of air which is removed in this way, and by vacuum locking the raft to the water a great stability is provided which permits diving from the raft without displacing it. The stability further permits boarding of the raft as with a ladder anchored to the side thereof without any chance of tipping the raft. The raft is described in the appended claims.
1. A buoyant body oating in water comprising: a top; means forming a buoyancy providing perimetral section below the top and immersed in the water; said body including a wall bounding a closed inner air chamber between the water and top; and normally closed opening means normally closed to prevent air flow between said chamber and the exterior atmosphere, but openable to open the chamber to the exterior atmosphere; the pressure in said chamber being substantially less than atmospheric, when the body is ilioating normally upright in the water without load, to vacuum lock the body to the water.
2. The combination defined in claim 1 in which said top has a non-skid tread surface thereon and the tread surface comprises a surface having cross-hatched grooves defining squares with raised flatted-oi mounds.
3. A floating body comprising: a downwardly and outwardly sloping top; and a side wall including a generally perimetral skirt portion extending downwardly a substantial distance from the underside thereof to form the bottom of the side wall; said skirt in cross-section constituting a block of coated plastic foam having suicient height and width to provide for -tloating the raft in unloaded condition with the top raised a substantial distance out of the water and the skirt substantially immersed in the water, said perimetral skirt being of a width to dene a generally centrally symmetric-compartment of substantial size inward of said skirt under said top, and open at its bottom; said top having a configured non-skid tread surface, and outwardly and downwardly sloping narrow drain channels, depressed relative to the top of the tread surface, extending from a central portion of the top of the body to the perimetral edges thereof and separating the tread surface into sections.
4. The combination defined in claim 3 in which the tread surface comprises a surface having cross-hatched grooves defining squares with raised flatted ot mounds.
5. The combination of claim 3 wherein said foam comprises a rigid plastic foam ring joined iush with the periphery of said top; said tread surface comprises grooves cross-hatched in the surface with flatted off mounds between said grooves; and said top comprises relatively closely spaced, segment shaped plywood core sections covered on top by a hardened bre glass and resin composition.
6. The combination defined in claim 5 in which the upper surface of said composition is covered by a nish plastic coating; said core sections are centrally joined by a plywood piece to provide a unitary structure; the underside of said core sections and piece are coated with a hardened fibre glass and resin composition to bind the piece and core sections together; and said composition binds said foam ring to said top.
7. The combination defined in claim 6 in which the inner ends of said core sections do not meet and a central space remains between them; a valve passage communicates said space with the air chamber formed under said top .by the ring and the exterior of said top; a normally closed valve in said passage; an anchor ring mounts on said plywood piece, and anchor means in said central space locks it in position.
8. A oating body comprising: a top; and a side wall including a generally perimetral skirt portion extending downwardly a substantial distance from the underside thereof to form the bottom of the side wall; said skirt in cross-section constituting a block of coated plastic foam having sufficient height and width to provide for oating the raft in unloaded condition with the top raised a substantial distance out of the water and the skirt substantially immersed in the water; said perimetral skirt being of a width to define generally centrally symmetric compartment means of substantial size inward of said skirt under said top and open at the bottom; said compartment constituting a closed air chamber between the water and top when the raft is in :the water; and normally closed opening means in said top, normally preventing air flow in either direction between said chamber and atmosphere, but openable to communicate said chamber with the exterior atmosphere.
References Cited UNITED STATES PATENTS 2,287,518 6'/ 1942 Flynn 9-11 2,421,171 5/ 1947 Trautvetter et al 52-181 2,858,790 11/1958 Russell, Jr. 9-11 3,048,859 l8/1962 Maillot 9-11 3,090,339 5/1963 Carr 9--11 3,172,343 3/1965 Jacobs 52-177 3,179,076 4/ 1965 Sheiiield 9 1 1 3,344,764 l`0/ 1967 Ziermann 9--11 3,035,286 5/ 1962 Brill 9-11 MILTON BUCHLER, Primary Examiner S. W. WEINRIEB, Assistant Examiner U.S. Cl. X.R. 4G-91; 272--1 B