Toy Vehicle With Transverse Energy Distribution Means

Abstract

A toy vehicle such as a car, with wheels attached to a body and a weight coupled to the body and movable in a direction transverse to the direction of motion of the vehicle to absorb or distribute energy when the vehicle strikes obliquely against a barrier that would tend to cause the vehicle to bounce sharply away. The energy may be distributed between the weight and the vehicle by slidably mounting the weight on the front axle, ahead of the center of gravity.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the field of toy vehicles adapted to be propelled along a track having barriers at the edges to keep the vehicles on the track. In particular it relates to the placement of a movable weight in such vehicles and coupled thereto to distribute transverse force imparted to the vehicles upon striking the boundaries obliquely.

2. The Prior Art

In copending U.S. Pat. application Ser. No. 126,818 filed Mar. 22, 1971, entitled TOY VEHICLE RACING GAME and assigned to the assignee of the present invention there is described a toy racing game in which spring-driven toy cars race around a closed loop track under the periodic speed control of operator-players. The cars themselves are described in greater detail in copending U.S. Pat. application Ser. No. 126,817, filed Mar. 22, 1971, now U.S. Pat. No. 3,735,526, entitled SPRING WIND-UP MECHANISM, also assigned to the assignee of the present invention. As described, the cars pass through individual slow-down devices once each lap. If the person in charge of one of the slow-down devices actuates the control at the proper time just before the car associated with that device passes through it, the device will be deactivated so as not to interfere with the progress of the car on that lap. Thus the speed will stay high and that car may catch up with or move ahead of another car that was slowed down by another slow-down device.

The track is preferably made with several sections of different direction and radius of curvature and different amounts of bank. Banking the curved parts of the track helps keep the cars from jumping off, but it is still desirable to provide a rail to make sure that the cars do not jump off. Under preferred conditions the cars would only approach the rail but would not strike it with any great force. In actuality, the cars sometimes strike the rail quite hard and then bounce back toward the inside of the curve.

Several factors combine to rotate the car sharply in response to sharp impact against the rail. For one thing, the center of gravity is behind the point of impact. In addition, the rear wheels are made so that they have a higher coefficient of friction than the front wheels in order to transmit driving force, and the front wheels therefore tend to slip toward the inside of the curve while the rear wheels continue to drive toward the outside. The exact relationship of forces is quite complex, but the end result is frequently excessive rotation of the car.

It is one of the primary objects of this invention to provide means to redistribute the rotational forces acting on a wheeled toy that strikes a barrier obliquely.

Another object is to prevent excessive impact-induced rotation of a toy car that strikes the barrier along the edge of a track.

A further object is to provide frictional energy-absorbing means in a toy car to reduce the tendency of the front end of the car to rotate excessively away from the outside rail along a curved track section upon striking the rail obliquely.

Further objects will be apparent from the following specification together with the drawings.

BRIEF DESCRIPTION OF THE INVENTION

The wheeled toy vehicle of the present invention is provided with a weight that can move in a direction generally transverse to the direction of movement of the vehicle. The weight moves in the direction to compensate for generally transverse acceleration caused by an oblique impact on the vehicle. The preferred arrangement of the weight in a four-wheeled toy car is in the form of a hollow cylinder slidably mounted on the front axle. The center of gravity is behind the front axle, and the rear axle is solidly connected to the rear wheels and is driven by a motor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a curved section of a toy race track with toy race cars on it.

FIG. 2 is a plan view of a toy race car constructed according to the invention and with part of the body broken away to show internal constructional features.

FIG. 3 is a side view of the toy car of FIG. 2 with part of the body broken away to show the interior.

FIG. 4 is a cross-sectional view of the car in FIGS. 2 and 3 and the directional stabilizing weight.

FIG. 5 is a diagrammatic cross-sectional view of a race track and toy car prior to impact of the car against the rail of the track.

FIG. 6 is similar to FIG. 5 but at a time just after the impact between the car and the rail.

FIGS. 7 and 8 are diagramatic plan views of the car of FIGS. 2 and 3 striking a curved barrier in different ways.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a fragment of a track 11 for a toy racing game. The entire track is usually a closed loop, preferably with some straight sections and other curved sections of different direction and degree of curvature, but the track, itself, is not part of the present invention. Along the outside edge of the curved track 11 is a low wall, or rail, 12. Another rail 13 forms a boundary on the other side of the track, and the racing surface 14 between these rails is not only banked, but the degree of bank increases toward the outer rail 12.

The curvature of the racing surface that results from increasing the angle of bank toward the outside of curves in the track 14 helps to guide toy cars, such as the cars 16 and 17, along the track and around the curves. The cars 16 and 17 are shown in typical positions that occur as they race along the track 11. The car 16 is in a position that it might occupy if it were going very fast, and the car 17 is in a position typical of a slower moving vehicle.

There is relatively little difficutly in making the cars follow acceptable paths along the surface 14 as long as the vehicles are moving slowly, but the object of the game is to cause the vehicles to move as fast as possible and this, in turn, causes them to climb well up on the steeply banked outer portion of the curves in the track 11. Without the outer rail 12, the cars would frequently go over the edge of the track, particularly if there were a series of sharp directional changes as there would be if the track had an S-curve or a chicane. The car 16 is shown in the position that would cause it to go over the edge of the track 11 if the outer rail 12 were not present. As it is, the car 16 would strike the outer rail 12 obliquely. When the car strikes the rail 12 with substantial force, it tends to rebound sharply toward the inner rail 13. If the impact is great enough, the car may even turn around so as to be headed the wrong way.

It would be preferable for the car 16 to follow the curvature of the outer part of the racing surface 14 as closely as possible instead of zigzagging between the rails 12 and 13. FIG. 2 shows the means for reducing rebound of the car 16 and keeping it traveling in the proper direction. The car includes a body 18 that forms a support structure for all of the components. Two front wheels 19 and 20 are mounted on a front axle 21 that passes through the sides 22 and 23 of the body 18 near the front end. The device for minimizing rebound is a cylindrical weight 24 slipped over the axle 21. The weight 24 is shorter than the distance between the sides 22 and 23 and is therefore free to slide back and forth on that part of the axle 21 within the body 18.

At the back end of the car 16 is a back axle 25 with two back wheels 26 and 27 rigidly attached to it to rotate therewith. The back wheels are the drive wheels of the toy car and the back axle 25 is releasably connected to a spring drive motor within the body 18 as described in the aforesaid U.S. Pat. No. 3,735,526. In order to transmit as much power from the motor to the track surface as possible, the back wheels 26 and 27 have rubber tires 28 and 29, respectively. The front wheels 19 and 20 do not have such tires and are normally made of a relatively hard (i.e., harder than rubber tires 28 and 29) plastic that has a lower coefficient of friction with respect to the track surface 14 in FIG. 1 than the coefficient of friction of the rubber tires 28 and 29. The two front wheels 19 and 20 are at all times parallel to each other and to the two rear wheels 26 and 27. By making the front wheels of lower friction material than the rear wheels, the front wheels tend to slip slightly toward the inside of a banked curve and thus help to steer the car around the curve.

FIG. 3 shows a side view of the car in FIG. 2 and illustrates the way that the weight 24 is slipped over the axle 21. As may be seen, the weight is in the form of a hollow cylinder and has a substantially larger inner diameter 31 than the outer diameter of the axle 21.

FIG. 4 shows that the weight 24 hangs on the axle 21 and can, therefore, slide relatively freely, although, of course, there is a small amount of friction between the weight and the axle. The axle 21 passes through aligned openings 32 and 33 in the body 18.

The effect of the weight 24 in reducing any tendency of the car 16 to spin upon striking the outer rail 12 is shown in FIGS. 5-8. In FIGS. 5 and 7 the car 16 is approaching the outer rail 12 and is right at the point of impact. The movement of the car is generally longitudinally along the surface 14 of the track, but because the track curves more rapidly than the car is turning, the car is moving toward the rail 12 as indicated by the arrow 34. As may be seen, the weight 24 is near the side 22, which is the side of the car 16 that faces the inner part of the curve of the track. As soon as the front part of the car 16 strikes the rail 12, the weight 24, by virtue of its momentum, slides along the axle 21 toward the other side 23.

When the car 16 strikes the rail 12, the impact, which would be taken by the right front wheel 20, would tend to spin the car counterclockwise as indicated by the arrow 36 in FIG. 7. The location of the center of gravity 37 of the car between the front axle 21 and the back axle 24 has a bearing on the tendency of the car 16 to spin in response to the impact. The center of gravity is the point at which the mass of the car 16 would be located for straight line movement, and the farther back it is, the greater the tendency of the car to spin. Another factor that would affect the tendency of the car 16 to spin is the polar moment of inertia. The mass of the car is, of course, not concentrated at the center of gravity 37 but is distributed along the length of the car. The more mass there is at the ends, the less the tendency to spin. However, it is undesirable to add mass, for this would make the car too heavy to accelerate well, since acceleration, for a given driving force, is inversely proportional to the mass. Thus, placing the weight 24 near the front end of the car is beneficial insofar as reducing the tendency to spin, but it is more important to allow the weight to move along the axle 21 in response to the sideward acceleration of the car 16 as a result of the impact of striking the rail 12.

In any case, as the front end of the car 16 bounces away from the rail 12, the weight 24 is forced against the wall 23 of the body as shown in FIG. 6. The weight 24 tends to try to continue moving in a straight path tangential to the direction of movement of car 16 along the surface 14 of the track in spite of the fact that the front end of the car is moving to the right in the direction indicated by the arrow 38. When the side 23 of the car strikes the end of the weight 24, energy from the weight is transferred to the car and causes the front end of the car to move back toward the rail 12 or at least not to move away from the rail as rapidly as it had done during the initial bounce in response to the impact against the rail. Thus, the car tends to continue along a desired path on the surface 14 of the track.

In exaggerated circumstances, as shown in FIG. 8, the initial bounce of the front end of the car 16 away from the rail 12 may even cause the rear end of the car to spin against the rail. This secondary impact of the car against the rail 12 will cause the back end to swing around in the direction indicated by the arrow 39. This clockwise rotation of the car tends to offset the original counterclockwise spin produced by impact of the front wheel 20 against the rail and helps keep the car 16 on the proper path.

The car 16 is symmetrical and will work as well for right-hand curves as for the left-hand curve illustrated. In either case, the weight 24 helps the car follow a proper path, even on a serpentine track.

Claims

What is claimed is:

1. A toy comprising:

A. a support structure;

B. a plurality of road wheels attached to said support structure and having fixed, substantially parallel axes of rotation; and

C. a weight loosely coupled to said structure ahead of the center of gravity thereof and movable in a direction substantially transverse to the direction of movement of said toy in response to sudden acceleration of said toy in a direction having a substantially opposite transverse component to impact said structure and transfer energy from said weight to said support structure.

2. The toy of claim 1 in which two of said wheels have a substantially common axis of rotation and said weight is supported between said two wheels.

3. The toy of claim 2 in which there are at least two additional wheels having a second common axis of rotation and the center of gravity of said structure is between the first mentioned two wheels and said two additional wheels.

4. The toy of claim 3 in which said first-mentioned two wheels are in front of said additional wheels in the normal direction of travel of said toy and said weight is in front of said center of gravity.

5. The toy of claim 4 comprising, in addition, an axle common to both of said first-mentioned two wheels and attached to said support structure, said weight being slidably mounted on said axle.

6. The toy of claim 5 in which said weight is a hollow cylinder and said axle extends therethrough.

7. The toy of claim 6 in which said support structure is a hollow car body and said axle is a straight rod extending through said car body near one end thereof and said weight encircles said axle within said car body but is axially shorter than the portion of said axle within said car body, whereby said weight can slide on said axle.

8. The toy of claim 4 in which the road-contacting perimeters of said first-mentioned wheels are harder than the road-contacting perimeters of said additional wheels.

9. The toy of claim 4 comprising, in addition, a second axle common to said additional wheels, said additional wheels being non-rotatably mounted on said second axle to rotate as a unit therewith.

10. The toy of claim 1 in which said support structure comprises a hollow car body and said toy comprises, in addition,

A. a front axle mounted near the front end of said body and extending through first aligned openings in opposite sides of said body, a front pair of said wheels being mounted on opposite end portions of said axle outside of said sides; and

B. a rear axle mounted near the rear end of said body and extending through second aligned holes in said opposite sides, a rear pair of said wheels being rigidly mounted on end portions of said rear axle to rotate as a unit therewith;

said toy having a center of gravity between said axles.

11. The toy of claim 10 in which said weight is slidably mounted on said front axle between said sides and has a length along said front axle less than the distance between said sides, whereby it can slide along said front axle.

12. The toy of claim 9 comprising, in addition elastic tires encircling only said rear wheels.