Background of the Invention The present invention relates to a toy crab capable of moving laterally like a real crab. In general, there are lots of toy crabs capable of moving in all directions, but none of them can move laterally using a number of legs like a real crab.

So, the inventor of the present invention has invented the toy crab capable of moving in the right or left direction using the plural left and right legs like the real crab. The toy crab according to the present invention can move the plural legs like legs of the real crab by using a cam structure, and can move in the left or right direction by manipulating a switch.

Objects of the Invention Accordingly, an object of the present invention is to provide a toy crab capable of moving a number of right and left legs like a real crab by using a cam structure.

Another object of the present invention is to provide a toy crab capable of moving the plural left and right legs in the left direction or right direction by manipulating a switch.

Summary of the Invention According to the present invention, there is a toy crab which is operated by cam structure, the toy crab including: a housing 3 for fixing components; leg sets 2 having a number of right and left legs 23, each of the legs having an end connected to a fixed shaft 21 and a longitudinally central portion connected to a cam shaft 22a or 22b; an operating unit for operating the cam shafts 22a and 22b; and an upper body 1 coupled to the upper portion of the housing.

The operating unit includes: a motor 4 for generating driving power; a gear set 5 for transmitting the driving power generated by the motor 4 to operate the cam shafts 22a and 22b; dry cells for operating the motor 4; and a switch 6 for stopping the motor 4 or changing the rotational direction of the motor 4.

The right and left legs are coupled at their central portions to the cam shafts, and move like a real crab through articular motion by cam motion. The toy crab moves in the right or left direction by forward and backward rotation of the motor when a user manipulates the switch.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Brief Description of the Drawings Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: FIG. 1 is a perspective view, in brief, of a toy crab operated by a cam structure according to the present invention; FIG. 2 is a perspective view, in brief, of the inside of the toy crab according to the present invention;

FIG. 3 is a perspective view, in brief, of four pairs of legs operated by the cam structure; FIG. 4 is a perspective view,-in brief, of one leg assembled by cams; FIG. 5 is a perspective view, in brief, of the leg under another condition to show a leg structure in more detail; FIG. 6 is a view showing the cam structure for assembling the four pairs of the legs of the toy crab; FIG. 7 shows examples of cam of different shapes, wherein FIG. 7a is an exemplary view of the cam having a square cam shaft hole penetrated therethrough to have phase difference of 90° therebetween the adjacent legs, FIG. 7b is an exemplary view of another cam having a hexagonal cam shaft hole penetrated therethrough to have a phase difference of 60° between the adjacent legs, and FIG.

7c is an exemplary view of a further cam having cam shaft holes of the combined shape of the cam shaft holes of FIG. 7a and 7b to have a modified phase difference therebetween the adjacent legs; FIG. 8 is a front view showing a gear set for operating cam shafts by a motor; FIG. 9 is a plan view of the gear set of FIG. 8; and FIG. 10 is a perspective view, in brief, of the gear set for operating the cam shaft according to another embodiment of the present invention.

Detailed Description of the Invention The present invention will now be described in detail in connection with preferred embodiments with reference to the accompanying drawings. For reference, like reference characters designate corresponding parts throughout several views.

FIG. 1 is a perspective view, in brief, of a toy crab operated by a cam structure according to the present invention. In the toy crab according to the present invention, all components including leg sets 2 having a number of left and right legs are coupled to a housing 3 located on the lower portion of an upper body 1. That is,

the upper body 1 is coupled to the upper portion of the housing 3 in consideration of the outward appearance of the final product of the toy crab. The upper body 1 can be manufactured in the same shape of a real crab, but it would be appreciated that the upper body 1 can be manufactured in various shapes.

The upper body 1 is to simply realize the shape of the final product, but does not provide any operational functions. A switch 6 is mounted on the upper portion or a side portion of the upper body 1 to operate the toy crab of the present invention.

FIG. 2 is a perspective view, in brief, showing a state in which the upper body 1 is removed from FIG. 1 to show the inside of the toy crab according to the present invention.

The toy crab includes a motor 4 mounted on the upper portion of the housing 3 being approximately in the form of a hexagon, a gear set 5 operated by the motor 4 and fixed to one side wall of the housing 3 to rotate cam shafts 22a and 22b, and the leg sets 2 coupled to the left and right cam shafts 22a and 22b and located inside the housing 3 and having a number of left and right legs coupled to a fixed shaft 21. Dry cells (not shown) may be detachably mounted on the lower portion of the housing 3 to operate the motor 4. Two dry cells of 1. 5V are inserted into the toy crab, and it can be easily carried out by those skilled in the art. FIG. 2 shows the switch 6 for operating the motor 4. The switch 6 can be mounted on the side portion or the upper portion of the upper body 1.

FIG. 3 is a perspective view, in brief, of four leg sets operated by the cam structure. Ends of the right and left legs are coupled to the fixed shaft 21 in order, and the central portions of the left and right legs are connected to the left and right cam shafts 22a and 22b respectively. The fixed shaft 21 is not rotated but fixed, and the cam shafts 22a and 22b are rotated to operate the left and right legs 23. A structure for moving the legs 23 in the left or right direction by the rotation of the cam shafts 22a and 22b will be described referring to FIGS. 4 to 6.

FIG. 4 is a brief view of one leg 23 assembled by the cam, and FIG. 5 is a view showing the leg 23 under another condition to explain the structure of the leg.

Each of the legs 23 includes a main leg member 231, a foot member 232, and a joint

member 233. The main leg member 231 has a hole 234 formed at one end thereof for inserting the fixed shaft 21 thereto, and is connected at the other end thereof to the foot member 232 by a fixing bolt 235. The joint member 233 has a cam fixing hole 238 formed at one end thereof for inserting the cam thereto, and is connected at the other end of to the foot member 232 by a fixing bolt 236.

The main leg member further has a cam moving hole 237 of an elliptical type formed at the central portion thereof for facilitating movement of the cam. The joint member 233 and the foot member 232 repeat articular motion according to the rotation of the cam shafts 22a and 22b. Support members 239 are mounted on the upper and lower portions of the rear of the main leg member 231 to prevent stop of the cam moving hole 237. The reason is to facilitate the cam motion by compensating an interval corresponding to the thickness of the foot member as the foot member is inserted between the joint member and the main leg member.

FIG. 6 is a view showing the cam structure for assembling the four pairs of the legs of the toy crab according to the present invention. Four cams 221,222, 223 and 224 are fixed to the cam shafts 22a and 22b having a square type section, and rotated by the rotation of the cam shafts 22a and 22b. The cams 221,222, 223 and 224 are mounted on one eccentric location of square holes for inserting the cam shafts 22a and 22b thereto. The four cams are assembled to have a phase difference of an angle of 90° therebetween the adjacent legs, and it can be easily carried out by those skilled in the art. The legs of the toy crab can repeat the articular motion in the same way of the real crab when the cam shafts 22a and 22b are rotated as the four cams are assembled to have a phase difference of the angle of 90° in order.

FIG. 7 shows examples of cam of different shapes: FIG. 7a is an exemplary view of a cam having a square cam shaft hole penetrated therethrough to have a phase difference of 90° therebetween the adjacent legs; FIG. 7b is an exemplary view of another cam having a hexagonal cam shaft hole penetrated therethrough to have a phase difference of 60° between the adjacent legs; and FIG. 7c is an exemplary view of a further cam having cam shaft holes of the combined shape of the cam shaft holes of FIG. 7a and 7b to have a modified phase difference

therebetween the adjacent legs.

In FIG. 7b, six legs are fixed to right and left sides and can do the articular motion by the phase difference of 60°, and in FIG. 7c showing the combined shape of the cams of FIG. 7a an 7b, the phase of the legs can be changed, and it can be easily carried out by those skilled in the art. For example, in FIG. 7a, eight right and left legs are coupled to the square hole of the upper portion and a diamond type hole of the lower portion in turn, thereby doing the articular motion by the phase difference of 45°. In case of using the cams shown in FIG. 7b, the cam shafts 22a and 22b must have a hexagonal section.

FIGS. 8 and 9 are front view and plan view showing the gear set 5 for operating the cam shafts 22a and 22b by the motor 4. When a gear 51 is rotated by the motor 4, a gear 52 is rotated, and a pair of gears 53 a and 53b being in the same form are rotated by a gear 52'connected to a shaft of the gear 52. After that, a pair of gears 54a and 54b are rotated by gears 53a'and 53b'connected to a shaft of the 53a and 53b, and then, gears 24a and 24b connected to the 54a and 54b are rotated in the same direction, and thereby, the cam shafts 22a and 22b are rotated in the same direction.

The motor 4 can be rotated in a forward or backward direction by the switch 6. For example, the motor is rotated in the forward direction when the switch 6 is located in a forward rotation position, and at this time, the toy crab is moved in the left direction. On the contrary, the motor is rotated in the backward direction when the switch 6 is located in a backward rotation position, and at this time, the toy crab is moved in the right direction. With control of the switch 6, the speed of the motor 4 can be controlled to one-step or two-step, and it can be easily carried out by those skilled in the art.

When the plural legs are fitted and fixed onto the fixed shaft 21 and the cam shafts 22a and 22b, couplings may be properly used between the legs for smooth rotation of the legs.

FIG. 10 is a perspective view, in brief, of the gear set for operating the cam shafts according to another embodiment of the present invention.

A worm gear 61 is formed integrally with a shaft of the motor 4. When the worm gear 61 is rotated, a pinion gear 62 is also rotated, and worm gears 63a and 63b coupled to both ends of a shaft 60 are rotated. Pinion gears 64a and 64b are rotated by the rotation of the worm gears 63a and 63b, and then, the cam shafts 22a and 22b are rotated in the same direction.

It would be appreciated that other gear set of different types from the gear set shown in FIG. 10 may be used, and it belongs to the scope of the present invention.

As described above, the toy crab according to the present invention can move the plural right and left legs like a real crab by the cam structure and move in the right or left direction according to turning of the switch.

While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.