US2183017A - Boat - Google Patents

Description

Dec. 12, 1939. E, G, GRANT 2,183,017

BOAT

Original Filed April 24, 1956 2 Sheets-Sheet l E. G. GRANT Dec. l2, 1939.

BOAT

Original Filed April 24, 1936 2 Sheets-Sheet 2 INVENTOR. EoMu/vo G. CR/Nifn Patented Dec. 12, 1939 UNITED STATE 76,214. Divided and this application yFebruary 14, 1939, Serial No. 256,291 l 3 Claims.

My invention relates broadly to boats and particularly to small boats of the class commonly termed dinghies, although as will become( apparent hereinafter, the size of the boats made according to my invention may be varied between extremely wide limits.

The major object of this invention is to provide a Yboat structure that is exceptionally strong and durable and which will be lighter and cheaper than boats of known types. By the construction of my invention, it is possible to build a dinghy or other relatively small boat which will be light enough for the ordinary person to handle and lift without assistance. This construction gives a boat which is sufficiently rigid so as not to be deformed,v but which is nevertheless suiciently resilient to avoid excessive stresses and strains being set up in its parts upon collision.

Itis a further object of my invention to provide a boat construction which readily lends itself to quantity production methods and which has a minimum of different parts so that the dealer need not carry a large stock of unrelated parts.

It is also an object of my invention to provide a boat embodying the foregoing characteristics which is substantially puncture-proof and can therefore be used in many instances where lightweight boats have heretofore been unsuited.

A still further object of my invention is to provide a boat using veneer planking anda novel means of joining the planks which obviates the need of screws, bolts nails or the like.

In general, the boat of my invention embodiesl a construction wherein the stresses and strains are taken up by lexure throughout the midsection of the planks instead of at the joints as is customary. f

In the drawings:

Fig..1 is a rear elevation of a modied form of dinghy showing a novel transom and joint construction;

Fig. 2 is a fragmentary section taken at 2-2 of Fig. 1;

Fig. 3 is a fragmentary section in perspective showing a portion of the transom and bottom of the boat of Fig. 1;

Fig. 4 is a fragmentary section showing a modifled form of the joint of Fig. 3; f

Fig. 5 is -a fragmentary perspective showing in detail the form of longitudinal joints used in the dinghy of Fig. 1;

Fig. 6 is a section of a novel type of veneer for use in any invention; l

y Fig. 7 is a side elevation partly in section showing molds for forming the dinghy;

Fig. 8 is a top plan of the molds of Fig. 7,;

Fig. 9 is an enlarged section showing the means of gluingthe longitudinal joints; and

Fig.` l0 is a cross lsection taken at llll0 of Fig. 7.

This application is a division of my copending application, Serial No. 76,214, led April 24, 1936.

Referring to the drawings by reference charactersI have shown my invention as embodied in a boat which is indicated generally at 9. As shown the boat includes steam bent ribs Il). Three-ply veneer is employed and in the drawings the outer plyis designated by the numeral 48, the centerply or core by numeral y4i and the inner ply by numeral 42. As in the forms of my invention previously described various numbers of knuckles can be used and for purposes of illustration I have shown in Fig. l a B-bottom boat having one knuckle on each side and one on rthe bottom. In that each joint is formed in the same manner, I have deemed it necessary toillustrate only one joint in Fig. 5 to be now described in detail.

The upper or side plank is designated generally by the numeral 38 and the adjoining bottom plank by the numeral 39, each of planks 43,8 and 39 `being of veneer with plys 4B,- 4| and 42. In forming the joint the outer and inner plys 4b and 42 respectively of each plank 58 and 39 are cut back a suitable distance from their respective edges, say for example from one to three inches, leaving opposing tongues 43 andf44 formed by the inner plys 4| of planks 38 and 39. These Ytongues 43 and 44 are placed in abutment land outer and inner ashing strips 45 and 46 are glued or other- ,1

wise adhesively fastened on to the tongues 43 and 44 by anysuitable cement or glue. The strips 45 and 46`are of a width to exactly ll the spaces leftA by cutting away the outer and inner plys of the planks 38 and 39, so that when the glued joint has set, a continuous surface is formed on both the outside and inside of the boat. The flashing strips are of course bent around the joint before the glue has set and as will be apparent the outer strip 45 will be slightly wider than inner strip 45 if the plys have been cut back the same distance. By this construction all screws or other fastening means are eliminated, a smooth strong joint-is obtained and a continuous shell of 3-ply veneer is formed. By eliminating the fastening .In v1nak-ng veneer it is 4convention practice .to

have the grain of the outer plies run substantially at right angles to the grain of the center ply for obvious structural reasons. As mentioned in describing the first form of my invention, I prefer to have the grain of the outer plies of my planks substantially parallel with the axis of the boat. In placing the flashing strips, however, there are two main features to be considered, first adequate shear strength in the joint at the juncture of tongues 43 and 44, and second the exibility required to bend the strips around the corner formed by the juncture of said tongues. If the grain of the strips is parallel to the edge of the planking, maximum flexibility for construction purposes is obtained, but the shear strength is minimum, and if the grain runs at right angles to the plank edge, the shear strength of the joint is maximum, but it is impossible to bend the strip around the corner without breaking. I have found that by placing the strips with their grain at a slight angle, say from to 20 to their longitudinal axis, that a satisfactory compromise between these two conditions is effected and the joint will have both adequate shear strength and flexibility for forming. I have further found that by giving these angles reverse slopes that still further shear strength and stiffness are given to the joint. These features are best seen in Fig. 5 where it will be noted that the grain of strip 45 has a negative slope of around with respect to the longitudinal axis of the strip, and that the grain of the strip 4B has a positive slope of approximately the same angle with respect to its longitudinal axis. It will be understood that these angles while preferably equal, need not be so, and that the amount of the respective angles will vary with the material being used and the exact dimensions and shape of the boat being constructed.

The glued hashing strip type of construction gives a boat which is lighter, cheaper and stronger than the chine type previously described, which is itself lighter, cheaper and stronger than existing types of boats. Likewise, this type of boat takes up more ilexure in the plank midsection and will stand more flexure at the joints, and smaller knuckle angles are therefore practical which means a wider range of shapes and designs in construction.

In Figs. 2, 3 and 4 I have illustrated a novel type of joint for accomplishing the juncture of the bottom and sides of the shell with the stern piece or transom. In all of these figures I have shown the planks and transom as made of veneer and it will be seen that they are each recessed by cutting back their respective center ply 4l. A metal strip 4l such as brass or other noncorrosive material is bent to the angle made between the adjoining faces of the transom l2 and bottom plank 39. The lengths of the angled portions of the strip 47 are such as to completely ll the recesses formed in the transom and bottom plank, and are preferably formed with teeth 48 on their upper and lower` faces adapted to be embedded in the inner and outer plies of the veneer when the boat is formed. The heel 49 of the strip 4l may be bowed out to allow the outer plies 43 to be beveled and placed ush with its outer surface as shown in Figs. 2 and 3, or it can be a simple bend entirely enclosed by the outer plies which are made to abut at the joint as illustrated in Fig. 4. The form of Figs. 2 and 3 affords more protection to the joint against sliding the boat on the sand. In each case it is preferable to fill the joint and surround the strip 41 with waterproof cement or glue to prevent leakage to the inside of the veneer. When using this type of joint I nd it advisable to make the transom in sections so that the teeth 4B are always pulling substantially with the grain, as this minimizes the danger of splitting the transom.

In Fig. 6 I have illustrated a novel form of veneer which is peculiarly well adapted for boat construction where waterproof material is of course desirable. For purposes of illustration I have shown a three-ply veneer, but it will be understood of course that more or less plies can be made without varying the method. Outer plies 50 and an inner ply or core 5l are provided in conventional manner, although for boat construction I prefer to make the outer plies 5i! a trifle thicker than the core 5I to give increased life and lateral flexibility with a consequent increased ability of the plank midsection to absorb all stresses by easy flexure.

In forming the veneer of my invention I place strips of raw rubber, such for instance as the type used in retreading automobile tires, between the various plies and vulcanize the wood ply strips to the rubber by the application of heat and pressure in known manner. I have found that the amount of heat and pressure required to form a perfect bond between the wood and the rubber is much less than that necessary in the construction of present known types of veneer which use casein glue, blood glue, phenol plastics and the like.

The veneer made by my method has a great many advantages over present types, particularly for boat construction. It is of course thoroughly waterproof and much more resilient than the veneer made with binders which dry out brittle, and especially is valuable in making the flashing strip joints heretofore described. The vulcanized rubber not only makes a better and more permanent bond between the wood plies, but also with the metal joining strips 41 if these are used. Another advantage of the rubber bonded veneer resides in the ease with which the veneer or the boat made therefrom can be patched, for a quick drying rubber cement can be used which makes a waterproof and durable patch with a minimum of effort.

Referring now to Figs. '7 to 10, it will be seen that I have provided a simple and rapid means of forming the boats of my invention with particular reference to the gluing or cementing of the flashing strips shown as a feature of the second form of boat construction hereinbefore described. The numeral 68 indicates a bottom or lower mold made of any suitable substance such as concrete for example, and the numeral 6I denotes an upper or interior mold member made of suitable material and adapted to t inside of the mold 6l) as best shown by Fig. l0.

The interior of mold 60 is shaped to properly form the boat to be built and is provided with a plurality of grooves 62 positioned to receive the joints or seams of the boat, and a series of transverse grooves 63 opposite the positions of the ribs l of the boat, and the joint between the transom and the bottom planks. The inner mold 6| is likewise provided with longitudinal and transverse grooves numbered 64 and 65 respectively which are directly opposed to the grooves of mold 60 when the mold 6I is lowered into position by any convenient means such for example the cables 66. Air bags 6l and 68 such as hoses are provided in the grooves of lower` mold 60 and up- 75 per mold 6| respectively and may be made in any convenient form to it their respective grooves.

In forming a boat by the use of the foregoing molds the outside hashing strips 45, the tongued planks for sides and bottom and the inside flashing strip iii are placed in position in the lower mold (iii with the air bags 61 in place and only partially inflated. The inner mold 6| with its airbags 63 is then lowered into position forcing the shell to assume the position of the mold, the necessary glue or cement having been placed between the flashing strips and their respective tongues. The air bags 6l and 68 are then iniiated to the required pressures to give exactly the correct forces to the joint and the whole allowed to stand until the glue has Set. The upper mold is then removed and the ribs lll are put in place and the mold 6l again lowered into position with its transverse air bags inflated to glue the ribs to the shell. It will be apparent of course that numerousvariations in this procedure may be followed. For instance the two steps may be combined by placing the ribs in position when the shell is formed and gluing both joints and ribs at once, or if desired separated molds may be used, one pair for gluingthe seams of the shell and a second pair for gluing the ribs. However, in every case it will be found that complementary molds are necessary and preferably that they be provided with elastic means for regulating the pressure on opposite sides of the joints.

While the forms of my invention shown and described herein are now deemed the preferred forms and are fully capable of attaining the objects and providing the advantages herein mentioned, it is to be understood that they are zmere ly illustrative of the broad principle involved in my invention as dened by the appended claims. Having thus described my invention I claim:

l. In a boat having ribs bent to form knuckles termediate layer, thelayers overlying and underlying said abutting edge portions having spaced edges, flashing strips located in the spaces between the edges of the overlying and underlying iayers, and secured to the intermediate layer, the grain of the overlying and underlying layers being parallel to their length, the grain of the flashing strips being at a relatively small angle to the joint covered thereby, the grain of the overlying and underlying flashing strips being reversed with respect to each other.

2. A boat including a shell comprising a plurality of longitudinally extending planks, said planks each comprising a plurality of layers of veneering secured together, the intermediate layer of each plank having joints with the longitudinal edges directly abutting one another, the longitudinal edges of both the inner and outer layer being spaced from each other to expose the inner and outer surface of the intermediate layer, a flashing strip on the inside and a hashing strip on the outside of the intermediate layer and positioned between the spaced edges of the inner and outer layers respectively to close the joint, the flashing strips being secured to the intermediate layer, said planks having the grain of the inner and outer layers parallel to their length, the grain of the ashing strips being at a relatively small angle to the joint covered thereby, the grain of the ashing strip on the inside ci the intermediate layer being reversed with respect to the grain of the hashing strip on the adjacent outside flashing strip.

3. A boat including a shell comprising a plurality of spaced, transverse ribs and longitudinally extending planks secured to said ribs, said planks each comprising a plurality of layers of veneering secured together, said ribs being bent to form knuckles, the intermediate layer of each plank having joints at the knuckles with the longitudinally edges directly abutting one another, the longitudinal edges of both the inner and outer layer being spaced from each other to expose ythe inner and outer surface of the intermediate layer, a flashing strip on the inside and a ashing strip on the outside of the intermediate layer and positioned between the spaced edges of the inner and outer layers respectively to close the joint, the flashing strips being secured to the intermediate layer, said planks havingathe grain of the inner and outer layers parallel to their length, the grain of the flashing strips being at a relatively small angle to the joint covered thereby, the grain of the iiashing'strip on the inside of the intermediate layer being reversed with respect to the grain of the hashing strip on the adjacent outside flashing strip.

EDMUND G. GRANT.

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