US 3840319 A
Description (OCR text may contain errors)
United States Patent [19.1
Rhoda MOLD lNSERT  Inventor: Ralph A. Rhoda, Orinda, Calif.
 Assignee: Berkeley Pump Company, Berkeley,
 Filed: Mar. 2 8, 1973 ] Appl. No.: 345,738
 US. Cl. 425/470, 115/16  Int. Cl B28b 7/16  Field of Search 425/470, 110, 111, 112,
 References Cited UNITED STATES PATENTS 2,807,065 9/1957 Den Dooven 164/125 X 3,503,583 3/1970 Jester 425/470 X 1 oer. s, 1974 Primary Examiner-Andrew R. .luhasz Assistant Examiner'John S. Brown Attorney, Agent, or Firm-Harris Zimmerman  ABSTRACT A mold insert for use with boat hull molds preforms a portion of a molded boat hull to create a receptacle to receive a propulsion unit for the boat. The mold insert, which may be used with a variety of hull molds, forms a receptacle which mates exactly with a propulsion unit, thereby alleviating many installation problems and reducing installation costs, and reducing the incidence of leaks and installation failures. For waterjet propulsion units, the mold insert creates a channel extending from the deadrise of the hull to the transom to non-turbulently conduct water to the intake port of the propulsion unit.
8 Claims, 14 Drawing Figures i PATENIED OCT 8 4 SHEEI 1 0f 2 8mm 40,319 PATENltD SHE am: 2 3
FlG 13 MOLD INSERT BACKGROUND OF THE INVENTION Most small pleasure boats currently constructed and sold are created from an assemblage of separate parts which are manufactured for the boating industry in general, and not for a specific craft. For example, myriad boat hulls of various lengths and configurations are produced with no accommodation or regard for the propulsion means which must subsequently be in stalled. Construction of a finished boat, therefore, involves a difficult choice of propulsion unit to match a particular hull design. Furthermore, the installation of the propulsion unit involves virtually a custom fit in the hull, which is a time-consuming and expensive process. Also, the possibility of mis-installation of the propulsion unit is greatly increased.
When matching a water-jet propulsion unit with a hull configuration, the problem of custom fitting the unit into the hull can be acute. The orientation of the unit with respect to the transom and the hull bottom is critical, as is the angular relationship between the thrust of the jet unit and the drag of the hull in the water. Also, the jet intake must be continually supplied with a non-turbulent stream of water from the water flowing under the hull. In the prior art, these interrelated factors have been coordinated at best in a haphazard fashion with patch-and-fill techniques. The boats produced in this manner have lacked uniform quality, and an unwarrented element of risk has entered into the purchase of one of these craft.
SUMMARY OF THE INVENTION The mold insert of the present invention overcomes the haphazard custom-fitting of jet propulsion units to hulls while increasing the possibile combinations of jet drives and hull designs. The mold insert is employed during the forming of a boat hull to specially form a portion of the hull into a receptacle which receives the propulsion unit. The receptacle is molded into the portion of the hull where the transom joins the keel at the centerline. The mold insert may be used with many different hull molds to create a receptacle which will mate exactly with a pre-assembled jet drive unit, regardless of the overall hull configuration.
The receptacle includes the segment of the transom to which the jet drive unit is secured, thus ensuring the proper orientation of the jet units with respect to the hull. The segment of the transom surface also includes portions to be cut out so that control rods and a cooling water supply pipe may extend into the boat. The receptacle also provides a channel formed in the hull which smoothly conducts water into the intake port of the jet drive. The pre-forming of a channel of optimum shape and size assures proper water flowto the jet pump.
The insert includes a horizontal base portion which extends forward from the transom area with a slight taper symmetrical with the centerline, the forward end being perpendicular to the centerline and having a slight V rise from the centerline. A channel is formed in the base portion by a panel extending from the middle of the base portion obliquely upward to the transom portion. The panel joins vertical sides which extend to the base portion. The aft end of the channel and-the base portion terminate in the transom portion which extends upward therefrom forming an angle slightly greater than with the base. The transom includes offset portions for cutouts and for mounting surfaces for the propulsion unit, and flanges extending obliquely rearward. v
THE DRAWING FIG. 1 is a perspective view of the mold insert of the present invention.
FIG. 2 is a side sectional view of the mold insert.
FIG. 3 is a front sectional view taken along line 3-3 of FIG. 2.
FIG. 4 is a front sectional view of the mold insert taken along line 4-4 of FIG. 2.
FIG. 5 is a front sectional view taken along line 55 of FIG. 2.
FIG. 6 is a front sectional view taken along line 6-6 of FIG. 2.
FIG. 7 is a side sectional view taken along line 77 of FIG. 3.
FIG. 8 is a top sectional view taken along line 8-8 of FIG. 3. j
FIG. 9 is a top sectional view taken along line 9-9 of FIG. 3. I
FIG. 10 is a front sectional view taken along line l0l0 of FIG. 13.
FIG. 11 is a front sectional view taken along line 11-11 of FIG. 13.
FIG. 12 is a front sectional view taken along line 12-12 of FIG. 13.
FIG. 13 is a top view of the mold insert of the present invention.
FIG. 14 is a side view of a trimmed mold insert of the present invention.
. DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention comprises a mold insert which is inserted in the mold of a boat hull. As shown in FIG.
1, the mold insert 16 has lateral surfaces 17 and 18 As shown in FIG. 13, the channel 24 is symmetrical about the centerline 19. Also, beginning at the junction of the top panel 26 and the lateral surfaces shown in cross-section in FIG. 10, the lateral surfaces begin to form a V-shape as their junction at the centerline angles downward, as shown in FIG. 11. The V-shape is increasingly pronounced at the end 21, as shown in FIG. 12. This V-shape is intended to blend into the deadrise common to any hull, making the mold insert compatible with most all hull molds.
The junction of the top panel 26 and the lateral surfaces 17 and 18 is rounded, providing a smooth transition into the channel, as seen in FIG. 2. The top panel is stepped at surfaces 27 and 28 to create mounting surfaces in the hull for the jet drive unit. The vertices 31 and 32 formed by the top panel and the sides 27 and 28 are initially rounded, as shown in FIG.'6, become seen in FIG. 5, and are nearly perpendicular vertices at the midlength of the channel, as depicted in FIG. 4. The cutout surface 29 in the top panel and the corresponding cut out surface 33 in the upright member, shown in FIGS. 2 and 3, delineate with a marker line areas in the boat hull which are cut out during installation. This pre-designation of areas to be removed greatly facilitates installation.
The upright member 22 includes offset surfaces 34 and 36, as shown in FIGS. 1 and 3. Offset surface 34 forms an area in the molded hull through which an aperture for the cooling water supply pipe is cut. Because the supply pipe is not parallel to the centerline, the surface 34 is offset in the vertical plane from the centerline, as shown in section in FIG. 9, so that the pipe will enter the surface 34 perpendicularly. The offset surface 36 forms an area in the molded hull in which openings for the control rods will be made. These rods extend rearwardly from the transom, toward the centerlineand the plane of the lateral surfaces. To allow these rods to enter the hull perpendicularly, the surface 36 of the mold insert is offset in the vertical plane both from the upright member 22, as shown in FIG. 7, and from the centerline, as shown in FIG. 8.
These offset surfaces reduce thepossibility of leaks in the finished hull. I
The mold insert 16 provides a means of modifying the configuration of a great many hull designs to permit them to accommodate exactly a jet propulsion unit. The predetermined angle between the upright member 22, which forms the transom portion of the receptacle, and the lateral surfaces 17 and 18, which are parallel with the keel, ensure the proper orientation of the jet drive. The channel 24 creates a rising passageway in the hull to direct a stream of non-turbulent water to the jet drive. The outline 37, shown in FIGS. 1 and 3, provides a raised face for the placement of the external portion of the jet drive assembly. With the preformed cutouts 29 and 33 to reduce installation time, and the offset surfaces 34 and 36 to eliminate leaks, the mold insert provides an ideal way to overcome the customfitting and guesswork found in the prior art, while retaining the wealth of unique combinations of hull designs and propulsion units.
Whereas in the prior art each and every finished boat hull had to be modified to receive installation of a jet propulsion unit, the present invention requires only that the hull mold be modified once, to produce a great many hulls which require no alteration prior to propulsion unit installation. To modify the hull mold, a mold insert 16 is appropriately trimmed and secured to a mold, as shown in FIG. 14. To accomplish this, the insert is situated and aligned in the mold, using the rear portion 40 of the lower edges of the side panels 27 and 28 as position control surfaces which are flush with the mold surface. The remaining portions of the lower extremities of the side panels, the lateral surfaces and the -lower portions of the upright member 22 are then scribed and cut so that the insert rests evenly in the mold and conforms to the deadrise of the hull.
Next, the flange 23 is trimmed to remove portions 41 of the flange, shown in phantom, which interfere with the transom forming area of the mold. The insert is then secured in place with adhesive or the like, with the junctions filleted. The junction 42 of the channel 24 with the keel line of the mold is filled with fiberglass, clay or the like to provide a smooth transition into the channel. The boat mold is then ready to produce hulls to be used with a jet propulsion drive.
1. A mold insert for modifying a boat hull mold, comprising:
receptacle forming means to form a receptacle in said boat hull to receive a jet-drive propulsion unit,
' 3. The mold insert of claim 2, wherein said lateral surface means, said channel forming means, and said transom forming means are all symmetrical about a common vertical plane.
4. The mold insert of claim 2, wherein said lateral surface means and said transom forming means form an angular relationship greater than 5. The mold insert of claim 4, wherein said transom forming means includes offset surfaces which are angularly offset from said vertical plane and from said transom forming means.
6. The mold insert of claim 1, wherein said channelforming means extends from said lateral surface means obliquely upward to said transom-forming means.
7. The mold insert of claim 6, wherein said channelforming means includes a toppanel perpendicular to said vertical plane and extending from said lateral surface means obliquely upward to said transom-forming means.
8. The mold insert of claim'7, wherein said channelforming means further includes two vertical panels parallel to said vertical plane and extending from said lat-" eral surface means to said top panel and joined therewith, said vertical panels also joining said transomforming means.