Surfboard with removable tail surface area portion
o United States Patent 11 1 1111 3,879,782 Oliver Apr. 29;, 1975 [54] SURFBOARI) WITH REMOVABLE TAIL 3,409,920 11/1968 Brownley 9/310 E SURFACE AREA PORTION 3,516,099 6/1970 Morey et al /310 E [76] Inventor: Clifford Clinton Oliver, 2439 FOREIGN PATENTS OR C T ONS Grandview St. San iego, Calif. 166.686 1/1934 Switzerland 403/339 92110 23,780 11/1882 Germany 403/339 22 F&#39;] d: A 6, 1973 1 1 e ug Primary Examiner-Duane A. Reger 1 1 pp 385,896 Assistant Examiner-Galen L. Barefoot [52] U.S. Cl 9/310 E [57] ABSTRACT [51] hit. Cl. A63C 15/00 An improved surfboard h i a cut out in the tail [58] Field of Search 9/310 B, 310 C, 310 E; block portion Th periphery of the cut out is pro- 403/3801 333 vided with a grooved slot. A removable tail surface portion is provided which includes a flange for remov- [56] References Cned ably mating with the periphery of the cut out portion UNITED STATES PATENTS of the tail block so as to form a unitary surfboard 1.608.000 11/1926 Ramlett 9/310 B structure A m a l pin f r l king together the 1,853.159 4/1932 Wclsh tail surface portion to the tail block portion while the 2.300.219 10/1942 Hannum same are mated is provided. 2,894,760 7/1959 Kolstad 3.337.886 8/1967 Ekstrom 9/310 E 8 Chums. 5 Drawmg Figures SURFBOARD WITH REMOVABLE TAIL SURFACE AREA PORTION BACKGROUND OF THE INVENTION The invention relates to surfboards and more specifically to a basic surfboard adapted to receive and lock thereto a removable tail surface portion having a selective configuration. 1 i  
  It is well known by surfers that the tailsurface configuration of a surfboard performs an important function in control and maneuverability of the board. Each different wave and loading condition requires v a different tail surface configuration for maintaining ideal control and maneuverability of the board. Presently surfboards are manufactured with the tail surface as a fixed integral portion of the tail block portion of the surfboard. When a surfer encounters changed loading or wave conditions he must select a surfboard that has the desired tail surface configuration for the changed condition. Obviously for surfing under a plurality of different conditions, a surfer must possess a plurality of boards having different tail surface configurations. This of course would not be practical because of the expense. Many surfers now surf under adverse conditions because they do not possess a plurality of boards having the desired different tail surface configurations. In addition, some of the most desirable surfing areas are inaccessible except by the surfer carrying his board to the area. The surfer is presently required to carry more than one board or choose a single board that will meet a single wave condition.  
 SUMMARY OF THE INVENTION The instant invention provides a low cost means for changing the tail surface configuration of a single basic board. The configuration is changed by removing the existing tail surface and replacing it with one selected from a plurality of low cost, light weight, interchangable tail surfaces having different surface configurations.  
  The invention provides a low cost means for enabling a surfer to possess &#39;a board having the desired tail surface configurations by possessing several different shaped tail surface inserts that are light in weight and small in size that are easily transportable.  
  These features and other advantages of this invention will become readily apparent upon reference to the following description, when taken in conjunction with the accompanying drawings, wherein:  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the bottom view of a surfboard.  
  FIG. 2 is a prospective cut away view of the rear portion of the surfboard with the tail surface removed.  
  FIGS. 30 and 3b show two additional tail surface configurations.  
  FIG. 4 is a cross-sectional side view of the rear portion of the surfboard.  
 DETAILED DESCRIPTION OF THE PREFERRED IMBODIMENTS Referring now to FIG. I, a basic surfboard 10 has a bottom portion 12. The bottom portion 12 has a center line 14 running the longitudinal length of the surfboard 10. The board 10 has a rear tail block portion 16. which includes mounting means 18 for receiving and mating to a removable tail surface portion 20 to form a unitary surfboard structure.  
 &#39; Referring&#39;now to- FIG. 2, the tail block portion includes mounting means 18 that includes a slotted channel 22 positioned between walls 24, 26. The slotted channel 22 receives and mates with flange 28 of tail surface portion 20. The tail block portion 16 of the basic board includes &#39;a locking flange 30 with an apperiphery 38 that angles rearward from the tail block portion 16 &#39;so as to form a shape substantially that of a half diamond that is symmetrical with the center line 14 of the basic board (shown&#39;in FIG. 1). FIG. 3b shows a tail surface portion 20 having a rear periphery 38a that forms a semi-circle extending between the corner 40 and 42 of the tail block portion 16.  
  The tail surface portion 20 of the board 10 of FIG. 1 has a rear periphery 38b that has an elongated portion 44 on one corner of board 10 that tapers forward in a semi-arc to tail block portion 16 at the opposite corner of board 10.  
  The tail surface portion 20 of the board 10 of FIG. 2 has a rear periphery 360 formed by two semi-circles meeting at the center line 14 of the board inward from the outer corners 40a and 42a of the tail block portion 16 of the board 10.  
  it should be obvious how mating and interchangeability of the tail surface portion 20 to tail block portion 16 is performed. A short summary of explanation follows.  
  The basic board 10 as shown in FIG. 4 has a slotted channel for receiving flange 28 of the tail surface portion 20 so that the tail surface when mated forms a continuation of the surface lines of the basic board 10 as shown in FIG. 1, 3a, 3b so that a unitary surfboard structure is formed that resembles a conventional surfboard. When the two portions are mated in thus manher the aperature 32 through flange 30 is co-axial with aperture 34 through tail portion 20. The locking pin 36 is then inserted through the aligned apertures to secure the two portions together. A tapered pin 36 can be inserted from the top of the board toward the bottom until it is held in place by friction of engagement. The locking pin may also be threaded through threads provided in apertures 32, 34 or a keeper in the form of a blot may be inserted through smooth apertures 32, 34 and a nut threaded on the free end thereof. The opposite operation is employed for removing the tail surface portion 20 from the basic board 10.  
  From the foregoing it will be evident that the present invention has provided a surfboard with an interchangeable tail surface portion in which all of the various advantages are fully realized.  
 What is claimed is:  
 1. An improved surfboard comprising:  
 a unitary surfboard structure having a tail block portion with a cut away tip surface area;  
 a plurality of differently configured tail block tip surface area sections;  
 mating means for removably mating any selected one of said plurality of said tip surface area sections to said cut away tip surface area of said surfboard so as to provide a tip surface area of desired configuration to said surfboard; and  
 removable locking means for locking the mated one of said plurality of tip surface area sections to said surfboard;  
 said cut away tip surface area is substantially V&#34; shaped;  
 said mating means comprises a slotted channel on the 1 rear periphery of said tail block portion and each of said plurality of tip surface area sections include a flange for mating within said slotted channel.  
  2. The invention as defined in claim 1 wherein each side of the outer surface of said V forms an equal acute angle with the center line of said surfboard.  
  3. The invention as defined in claim 1 wherein said removable locking means comprises in combination apertures passing through said tail block portion and each of said tip surface area sections, said apertures are coaxial when said tail block portion and a selected one of said tip surface area sections are mated, and a removable pin passing through said apertures for maintaining a mated configuration.  
  4. The invention as defined in claim 3 wherein said apertures are threaded and said pin is threaded for threaded engagement there with.  
  5. The invention as definedin claim 1 wherein one of said plurality of tip surface area sections is substantially diamond shaped.  
  6. The invention as defined in claim 1 wherein one of said plurality of tip surface area sections has a convex outer periphery.  
  7. The invention as defined in claim 1 wherein one of said plurality of tip surface area sections has an outer periphery comprised of at least two curved portions in contact at the center line of said surfboard.  
  8. The invention as defined in claim 1&#39; wherein one of said plurality of tip surface sections has an outer periphery with an elongated portion on one side thereof.