A hull for a personal watercraft and a personal watercraft for children comprising said hull

Abstract

The present invention belongs to the field of vehicles for water transportation and recreation, more precisely to the field of personal watercrafts (PWC), also known as water scooters or jet skis. The invention pertains to a hull for a personal watercraft and a personal watercraft for children comprising said hull. The essence of the invention is that the shape of the hull has a concave recess in the bottom part of the hull arranged for contact with water, wherein said concave recess is provided in the middle part of the hull, i.e. below the seat area and below the steering element. Said concave recess is, in contrast to catamaran-shaped hulls, present only in a part of the hull, which allows formation of vacuum that ensures improved stability of the PWC. Thus, safer and easier use is ensured, which is particularly important for PWCs for use by children. Furthermore, the recess allows that the motor propeller is installed as high as possible, wherein the holder of the propeller is connected to the steering element to allow steering.

Description

[0001] A HULL FOR A PERSONAL WATERCRAFT AND A PERSONAL WATERCRAFT FOR CHILDREN COMPRISING SAID HULL

[0002] Field of the invention

[0003] The present invention belongs to the field of vehicles for water transportation and recreation, more precisely to the field of personal watercrafts (PWC), also known as water scooters or jet skis. The invention pertains to a hull for a personal watercraft and a personal watercraft for children comprising said hull.

[0004] Background of the invention and the technical problem

[0005] A personal watercraft (PWC), also called jet ski, sea-doo, or water scooter, is a primarily recreational watercraft that is designed to hold only a small number of occupants, who sit or stand on top of the craft, not within the craft as in a boat. PWCs have two style categories, namely a compact runabout, typically holding no more than two or three people, who mainly sit on top of the watercraft as one does when riding a motorcycle or quadbike, and a "stand-up" type, typically built for only one occupant who operates the watercraft standing up as in riding a motorized scooter. The latter is used primarily for doing tricks, racing, and in competitions. Both styles have an inboard engine driving a pump-jet that has a screw-shaped impeller to create thrust for propulsion and steering. Most are designed for two or three people, though four- passenger models exist. Many of today's models are built for more extended use and have the fuel capacity to make long cruises.

[0006] The problem of known PWCs is their unsuitability for use by children, as they are large, heavy and complicated to handle and drive. Specific instructions are to be followed in case a child should be a passenger on the PWC. However, children or their parents would also like to have specialized PWCs for their use. Hence, it is desirable to design a PWC suitable for children, which will enable easy and most importantly safe use. Prior art

[0007] Patent application US5879214A relates to convertible floating and sledding toy. The toy has an elongate hull for buoyantly floating the toy and child on a water surface, and for sliding downhill on a frozen snow-covered hill surface. For example, the hull may be a hollow blow moulded plastic body with downwardly extending ribs having a flat bottom surface. Handlebars are mounted to a steering shaft housed within the hull for steering the direction of the toy. The steering shaft can be releasably mounted with a water jet nozzle and alternatively with a snow riding ski. The toy mimics both a snowmobile and a jet-powered watercraft, for use in summer and winter. The waterjet nozzle is supplied with pressurized water from a swimming pool filtration system via a flexible hose.

[0008] Yamaha produces a fully inflatable ski jet, wherein the body construction and the materials differ from the present invention. The inflatable part is similar to the solution described in US5879214, wherein the Yamaha product does not have an engine and differs in the construction.

[0009] Patent application CZ219496A3 describes a water scooter, particularly for children, wherein the bottom of the body consists of a pair of side floats and between them in the front part there is float carrying the driving unit inside. This shape is similar to catamarans, while the present invention differs in the shape of the hull of the water scooter.

[0010] Description of the solution to the technical problem

[0011] The present invention aims to provide a hull and a PWC for children and solves the technical problem as defined in the independent claim. The preferred embodiments are defined in dependent claims. The essence of the invention is that the shape of the hull has a concave recess in the bottom part of the hull arranged for contact with water, wherein said concave recess is provided in the middle part of the hull, i.e. below the seat area and below the steering element. Said concave recess is, in contrast to catamaran-shaped hulls or floaters as disclosed in CZ219496A3, present only in a part of the hull, which allows formation of vacuum that ensures improved stability of the PWC. Thus, safer and easier use is ensured, which is particularly important for PWCs for use by children. Furthermore, the recess allows that the motor propeller is installed as high as possible, wherein the holder of the propeller is connected to the steering element to allow steering.

[0012] The hull is essentially a body with an upper surface with a space arranged to receive the user and a bottom surface arranged for contact with water, wherein:

[0013] - the upper surface is divided into: o a front part o a back part located on the opposite end of the nose, and o a seat part between said front and back parts, wherein in cross section o the front part is increasing from the nose towards the seat part and at the end of the front part a steering mechanism, usually a bar, is provided, o the seat part is the lowest part and is divided into a seat arranged to receive a user able to hold the steering mechanism and two spaces at left and right side of the seat arranged to receive the feet of the user, o and the back part is higher than the seat part,

[0014] - the bottom surface is divided into: o a front part below the front part of the upper surface, o a back part below the back part of the upper surface, o and a central part between said front and back parts of the bottom surface, wherein in cross section the bottom surface of the hull is shaped from two slightly convex parts and the concave recess between said convex parts, said concave recess being present below the seat area and below at least a part of the front part, at least below the steering element. In preferred embodiments, the dimensions of the concave recess or cavity, respectively, are:

[0015] - depth (height) of the recess from one quarter (25%) to one half (50%) of the height of the highest value of the height of the hull, most preferably from one third (33%) of the height of the hull,

[0016] - length of the recess is from one quarter (25%) to one half (50%) of the length of the hull, most preferably one third (33%) of the length of the hull.

[0017] The hull that is shaped in the above-described manner allows floating regardless of other components or the inflatable parts installed on said hull. The hull is preferably made in two pieces, the upper forming the upper surface and the bottom forming the bottom surface, wherein the space between them is empty. The battery and electronics are preferably installed inside the hull in said empty body. The position of the battery is usually in the front part of the hull and access to the battery is allowed with an opening with suitable closure that can be opened and closed when needed.

[0018] In a preferred embodiment of the invention the PWC for children comprises the following:

[0019] - the hull as described above, wherein the hull is preferably made from carbon, polyester or fiberglass material,

[0020] - a seat for the driver installed on said hull,

[0021] - a ladder, preferably made from inox material, installed approximately in the middle of the watercraft (middle along the length), to allow climbing into the watercraft, wherein said ladder may be provided with removable wheels for easier transport to the water / beach,

[0022] - at least one inflatable chamber surrounding said shell, wherein two inflatable chambers are preferably provided, i.e. , one in the front part and the second in the back part, wherein protective rubber layer is preferably provided around the circumference of the watercraft,

[0023] - a motor, i.e. an electric engine, installed in the concave recess that is essentially below a steering bar, wherein the propeller of the motor is provided with a protective guard to prevent injuries, - a steering bar with handles for controlling the motor and the driving direction, wherein the steering bar is provided with at least one, preferably with two or three buttons, wherein the first (essential) button is for motor control arranged for initiation and termination of driving, and the two optional are for driving in reverse and for initiation of a water pump, and wherein the steering bar is used to rotate the motor via a shaft so as to control the driving direction,

[0024] - a battery arranged to power the motor,

[0025] - an electrical circuit formed by suitable connections between the battery and the motor, wherein a main switch is provided between the battery and the motor, and wherein a switch is provided for controlling operation of the motor, said switch being controlled by the first button.

[0026] In a further preferred embodiment of the invention the PWC for children comprises the following:

[0027] - the hull as described above, wherein the hull is preferably made from carbon, polyester or fiberglass material,

[0028] - a seat for the driver installed on said hull,

[0029] - a ladder, preferably made from inox material, installed approximately in the middle of the watercraft (middle along the length), to allow climbing into the watercraft, wherein said ladder may be provided with removable wheels for easier transport to the water / beach,

[0030] - at least one inflatable chamber surrounding said shell, wherein two inflatable chambers are preferably provided, i.e. , one in the front part and the second in the back part, wherein protective rubber layer is preferably provided around the circumference of the watercraft,

[0031] - at least one rope is provided to allow grip of the PWC, wherein two ropes are preferably placed, one in the front part and one in the back part of the PWC so that a person can grip the rope almost at any point around the circumference of the watercraft,

[0032] - a motor, i.e. an electric engine, installed in the concave recess that is essentially below a steering bar, wherein the propeller of the motor is provided with a protective guard to prevent injuries, - a steering bar with handles for controlling the motor and the driving direction, wherein the steering bar is provided with at least one, preferably with two or three buttons, wherein the first (essential) button is for motor control arranged for initiation and termination of driving, and the two optional are for driving in reverse and for initiation of a water pump,

[0033] - a battery arranged to power the motor,

[0034] - an electrical circuit formed by suitable connections between the battery and the motor, wherein a main switch is provided between the battery and the motor, and wherein a switch is provided for controlling operation of the motor, said switch being controlled by the first button,

[0035] - a bipolar motor inverter connected into the electrical scheme between a second switch enabling operation of the button for reverse driving and the motor, said inverter being arranged to invert the rotation and hence the driving direction, wherein the second switch is controlled by the second button for reverse driving,

[0036] - optionally a water pump for ejecting water, wherein said water pump is installed under the seat and is controlled by the third button arranged to control the third switch, wherein the water pump is connected electrically to the battery via a blade fuse holder and said third switch.

[0037] The bipolar motor inverter and the water pump are strictly optional features.

[0038] In order to initiate driving, the user has to press and hold the first button to start driving, wherein the first switch closes the electrical circuit between the motor and the battery. For the duration of driving, the first button must remain pressed. In case the water pump is installed, the third button may be used to initiate a water blast from the water pump to create a similar effect as in known personal watercrafts for adults. In case reverse driving is needed, the user has to release the first button and press as well as hold the second button for reverse driving.

[0039] The inflatable air chambers are PVC or Hypalon essentially made as tubes of specific diameter and shape that corresponds to the shape of the hull. The inflatable air chambers are installed with webbing and suitable clamps. The shape of the tubes corresponds to the shape of the hull, wherein the dimensions of the hull and thus the tubes may be arbitrarily defined and adjusted with regards to intended size of users. For example, the hulls may be different sizes, such as for smaller and for older children.

[0040] The present invention successfully solves the technical problem and addresses the disadvantages of known solutions.

[0041] Brief description of drawings

[0042] The invention will be described in further detail based on exemplary embodiments and figures, which show:

[0043] Figure 1 The watercraft for children according to a possible embodiment

[0044] Figure 2 Top view (Figure 2a), side view (Figure 2b), cross section (Figure 2c) and the bottom surface (Figure 2d) of the hull of the watercraft

[0045] Figure 3 Side view of the watercraft without and with air chambers

[0046] Figure 4 Top view of the watercraft without and with air chambers

[0047] Figure 5 Diagram of the electrical circuit

[0048] Detailed description of the invention

[0049] Figure 1 shows a possible embodiment of the PWC 1 , wherein the PWC for children comprises the following:

[0050] - a hull 2 preferably made from carbon, polyester or fiberglass material,

[0051] - a seat 24 for the driver installed on said hull 2,

[0052] - a ladder 7, preferably made from inox material, installed approximately in the middle of the watercraft 1 (middle along the length), to allow climbing into the watercraft 1 , wherein said ladder 7 is provided with removable wheels 71 for easier transport to the water / beach,

[0053] - two inflatable chambers 31 , 32 surrounding said hull 2, one chamber 31 in the front part and the second chamber 32 in the back part, wherein protective rubber layer 34 is provided around the circumference of the watercraft, - two ropes 35a, 35b, wherein the first rope 35a in the front part and the second rope 35b in the back part of the PWC, so that a person can grip the rope almost at any point around the circumference of the watercraft,

[0054] - an electric engine 4, installed in the concave recess 23 that is essentially below a steering bar 6, wherein the propeller of the motor 4 is provided with a protective guard 5 to prevent injuries,

[0055] - a steering bar 6 with handles 61 for controlling the motor and the driving direction, wherein the steering bar is provided with at least one, preferably with two or three buttons, wherein the first (essential) button is for motor control arranged for initiation and termination of driving, and the two optional are a second button for driving in reverse and a third button for initiation of an optional water pump,

[0056] - a battery 8 (visible in figure 5, not visible in figure 1 ) arranged to power the motor 4,

[0057] - an electrical circuit (schematically shown in figure 5) formed by suitable connections between the battery 8 and the motor 4, wherein a main switch 9 and a voltmeter 10 is provided between the battery 8 and the motor 4, and wherein a switch 62 is provided for controlling operation of the motor, said switch being 62 controlled by the first button.

[0058] Figure 3 shows side view of the watercraft without and with air chambers 31 , 32, wherein there are seven rings 33 made from webbing to allow installation and fixation of air chambers 31 , 32 around the hull 2. Figure 4 shows top view of the watercraft without and with air chambers, wherein ropes 35a, 35b are visible.

[0059] As seen from figures 3 and 4, the inflatable air chamber is made from two separate parts, i.e. the front part 31 and the back part 32, wherein both parts 31 , 32 have several sections of different sizes and cross sections that allow optimal shaping of the watercraft 1 .

[0060] The front air chamber 31 is divided into seven sections, wherein the centre section has connection to two first intermediate sections, one on the left side and one on the right side, and each first intermediate section has a connection to a second intermediate section and each second intermediate section is connected to the outermost section. All seven sections together form an approximate shape of a letter II and create a symmetrical shape. The rope 35a is provided on all sections of the front air chamber 31.

[0061] The back air chamber 32 is divided in five sections, wherein the centre section has connection to two intermediate sections, one on the left side and one on the right side, and the intermediate section has a connection to the outermost section. All five sections together form an approximate shape of a letter C and create a symmetrical shape. The rope 35b is provided only in the central section and partly on adjacent sections.

[0062] The essence of the invention is that the shape of the hull 2. A preferred embodiment of the hull 2 is shown in figures 2a to 2d. The hull 2 has an upper surface 21 with a seat 24 arranged to receive the user and a bottom surface 22 arranged for contact with water, wherein:

[0063] - the upper surface 21 is divided into: o a front part 21 F, o a back part 21 B located on the opposite end of the nose, and o a seat part 21 S between said front and back parts 21 F, 21 B, wherein in cross section o the front part 21 F is increasing from the nose towards the seat part 21 S and at the end of the front part 21 F the steering mechanism 6, usually a bar, is provided, o the seat part 21 S is the lowest part and is divided into the seat 24 arranged to receive a user able to hold the steering mechanism 6 and two spaces 25 at left and right side of the seat 24 arranged to receive the feet of the user, o and the back part 21 B is higher than the seat part 21 s,

[0064] - the bottom surface 22 is divided into: o a front part 22F below the front part 21 F of the upper surface 21 , o a back part 22B below the back part 21 B of the upper surface 21 , o and a central part 22S between said front and back parts of the bottom surface, wherein in cross section the bottom surface of the hull 2 is shaped from two slightly convex parts 26 and the concave recess 23 between said convex parts 26, said concave recess 23 being present below the seat area 21 S and at least a part of the front part 21 F, preferably at least below the steering element 6.

[0065] In preferred embodiments, the dimensions of the concave recess 23 or cavity, respectively, are:

[0066] - depth (height) of the recess from one quarter (25%) to one half (50%) of the height of the highest value of the height of the hull, most preferably from one third (33%) of the height of the hull,

[0067] - length of the recess is from one quarter (25%) to one half (50%) of the length of the hull, most preferably one third (33%) of the length of the hull.

[0068] The length is calculated from the beginning of the recess as shown in figure 2b (dashed line marked with letter L), not the part with the highest depth. The height of the recess is marked with a dotted line marked with letter H in figure 2b.

[0069] The PWC 1 preferably further comprises a bipolar motor inverter 12 connected into the electrical scheme between a second switch 63 enabling operation of the button for reverse driving and the motor, said inverter 12 being arranged to invert the rotation and hence the driving direction, wherein the second switch 62 is controlled by the second button for reverse driving.

[0070] Optionally, the PWC may additionally comprise a water pump 14 for ejecting water, wherein said water pump 14 is installed under the seat 24 and is controlled by the third button arranged to control the third switch 13, wherein the water pump 14 is connected electrically to the battery 8 via a blade fuse holder 11 b and said third switch 13.

[0071] The electrical circuit of the PWC is shown schematically in figure 5. The electrical circuit is formed by suitable connections between the battery 8 and the motor 4, wherein a main switch 9 and a voltmeter 10, as well as a blade fuse holder 11 , are provided between the battery 8 and the motor 4, and wherein the switch 62 is provided for controlling operation of the motor 4, said switch being controlled by the first button. In case reverse driving is enabled, the bipolar motor inverter 12 is connected into the electrical scheme between the second switch 63 enabling operation of the button for reverse driving and the motor, said inverter 12 being arranged to invert the rotation and hence the driving direction, wherein the second switch 62 is controlled by the second button for reverse driving.

[0072] For embodiments with the water pump 14, the latter is controlled by the third button arranged to control the third switch 13, wherein the water pump is connected electrically to the battery 8 via a blade fuse holder 11 b and said third switch 13.

[0073] To initiate driving, the user has to press and hold the first button to start driving, wherein the first switch closes the electrical circuit between the motor and the battery. For the duration of driving, the first button must remain pressed. In case the water pump is installed, the third button may be used to initiate a water blast from the water pump to create a similar effect as in known personal watercrafts for adults. In case reverse driving is needed, the user has to release the first button and press as well as hold the second button for reverse driving.

Claims

Patent claims1. A hull (2) for a personal watercraft (1 ), wherein the hull (2) comprises an upper surface (21 ) and a bottom surface (22) arranged for contact with water, characterized in that the bottom surface (22) has a concave recess (23) provided in a central part of the hull (2), i.e. below a seat part (21 S) and at least partly below a front part (21 F), preferably at least below a steering element (6).

2. The hull (2) according to claim 1 , wherein the hull (2) is shaped as a body with the upper surface (21 ) with a space (24) arranged to accommodate a user and the bottom surface (22) arranged for contact with water, wherein:- the upper surface (21 ) is divided into: o the front part (21 F), o a back part (21 B) located on the opposite end of the nose, and o the seat part (21 s) between said front and back parts, wherein in cross section o the front part (21 F) is increasing from the nose towards the seat part (21 F) and at the end of the front part the steering mechanism (6), usually a bar, is provided, o the seat part (21 F) is the lowest part and is divided into a seat (24) arranged to receive a user able to hold the steering mechanism (6) and two spaces (25) at left and right side of the seat (24) arranged to receive the feet of the user, o and the back part (21 b) is higher than the seat part,- the bottom surface (22) is divided into: o a front part (22F) below the front part (21 F) of the upper surface (21 ), o a back part (22B) below the back part (21 B) of the upper surface (21 ), o and a central part (22S) between said front and back parts (22F, 22B) of the bottom surface (22), wherein in cross section the bottom surface (22) of the hull (2) is shaped from two slightly convex parts (26) and the concave recess (23) between said convex parts (26), said concave recess (23) being present below theseat area (21 S) and at least partly below the front part (21 F), preferably at least below the steering element (6).

3. The hull (2) according to claim 1 or claim 2, wherein the dimensions of the concave recess (23) are:- depth (height) of the recess (23) from one quarter to one half of the height of the highest value of the height of the hull (2), most preferably from one third of the height of the hull (2),- length of the recess (23) is from one quarter to one half of the length of the hull (2), most preferably one third of the length of the hull (2).

4. The hull (2) according to claim 3, wherein the dimensions of the concave recess are:- depth of the concave recess (23) is one third of the height of the hull (2),- length of the concave recess (23) is one third of the length of the hull (2).

5. The hull (2) according to any of the preceding claims, wherein the hull (2) is made from two pieces, an upper piece forming the upper surface (21 ) and a bottom piece forming the bottom surface (22), wherein the space between them is empty, wherein said space is configured to receive the battery (8) and electronics.

6. The hull (2) according to any of the preceding claims, wherein the hull (2) is made from carbon, polyester or fiberglass material.

7. A personal watercraft (1 ) for children comprising the hull (2) according to any of the preceding claims.

8. The personal watercraft (1 ) for children according to the preceding claim, wherein it further comprises the following:- the seat (24) for the driver installed on said hull (2),- a ladder (7), preferably made from inox material, installed approximately in the middle of the watercraft to allow climbing into the watercraft (1 ), wherein saidladder (7) may be provided with removable wheels (71 ) for easier transport to the water or beach,- at least one inflatable chamber (31 , 32) surrounding said hull (2), wherein two inflatable chambers are preferably provided, i.e., a first air chamber (31 ) in the front part and a second air chamber (32) in the back part, wherein protective rubber layer (34) is preferably provided around the circumference of the watercraft,- a motor (4), i.e. an electric engine, installed in the concave recess (23) that is essentially below a steering bar (6), wherein the propeller of the motor (4) is provided with a protective guard (5) to prevent injuries,- the steering bar (6) with handles (61 ) for controlling the motor (4) and the driving direction, wherein the steering bar (6) is provided with at least one, preferably with two or three buttons, wherein the first button is for motor control arranged for initiation and termination of driving, and the two optional are for driving in reverse and for initiation of a water pump,- the battery (8) arranged to power the motor (4), said battery installed in the empty space in the front part of the hull (2),- an electrical circuit formed by suitable connections between the battery (8) and the motor (4), wherein a main switch (9) is provided between the battery (8) and the motor (4), and wherein a switch (62) is provided for controlling operation of the motor (4), said switch (62) being controlled by the first button, wherein said electronics are installed in the empty space inside the hull (2).

9. The personal watercraft (1 ) for children according to claim 8, wherein it further comprises:- at least one rope (35a, 35b) is provided to allow grip of the PWC, wherein two ropes are preferably placed, a first rope (35a) in the front part and a second rope (35b) in the back part of the PWC so that a person can grip the rope almost at any point around the circumference of the watercraft.

10. The personal watercraft (1 ) for children according to any claim from 8 to 9, wherein it further comprises:- a bipolar motor inverter (12) connected into the electrical scheme between a second switch (63) enabling operation of the button for reverse driving and the motor (4), said inverter (12) being arranged to invert the rotation and hence the driving direction, wherein the second switch (63) is controlled by the second button for reverse driving.11 . The personal watercraft (1 ) for children according to any claim from 8 to 10, wherein it further comprises:- a water pump (14) for ejecting water, wherein said water pump (14) is installed under the seat (24) and is controlled by the third button arranged to control the third switch (13), wherein the water pump (14) is connected electrically to the battery (8) via a blade fuse holder (11 ) and said third switch (13).

12. The personal watercraft (1 ) for children according to any claim from 8 to 11 , wherein two air chambers (31 , 32) are provided.

13. The personal watercraft (1 ) for children according to the preceding claim, wherein each inflatable air chamber is made from two separate parts, i.e. the front part and the back part, wherein both parts have several sections of different sizes and cross sections that allow optimal shaping of the watercraft.

14. The personal watercraft (1 ) for children according to the preceding claim, wherein:- the first air chamber (31 ) is divided into seven sections, wherein the centre section has connection to two first intermediate sections, one on the left side and one on the right side, and each first intermediate section has a connection to a second intermediate section and each second intermediate section is connected to the outermost section, and wherein all seven sections together form an approximate shape of a letter II and create a symmetrical shape,- the second air chamber (32) is divided in five sections, wherein the centre section has connection to two intermediate sections, one on the left side and one on the right side, and the intermediate section has a connection to theoutermost section, wherein all five sections together form an approximate shape of a letter C and create a symmetrical shape.

Images