US 3698713 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
United States Patent [151 3,698,713
Jimerson 1 Oct. 17, 1972  GAMETOY LOCOMOTION 3,463,495 8/1969 Christensen ..273/86 E X APPARATUS 1,755,621 4/1930 Whitehouse ..273/86 E  inventor: Bruce D. Jimerson, 1815 Vallecito Drive San Pedro, Cam, 90732 Primary Exammer Anton O. Oechsle  Filed: June 18, 1970  ABSTRACT 21 AWL 47,549 Objects having different coefficients of friction may be propelled across a common playing surface by different modes of directional vibration under the con- U-S. E, C, A no] of opposing player5 the repetition rate of the  Int. Cl. vibrational modes are also made variable the pl s  Field of Searc 94 may command both the speed and heading of their 46/ 198/220 own objects. Such a locomotion apparatus has numerous applications as a competitive gametoy.
 References Cited UNITED STATES PATENTS 9 Claims, 28 Drawing Figures 2,330,946 10/1943 Bergmann A 1: I w I l I) g I! 50 I r z w I I l 4] J i I j-ZZ J 25 i i I? 24 k45 PATENTEDIIBI 17 I972 3' 698,7 1 3 sum 2 or 6 INVENTOR.
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I E L m m i I NVEN'T OR.
1 GAMETOY LOCOMOTION APPARATUS BACKGROUND OF THE INVENTION Reference to US. Pat. application Ser. No. 810,207, filed Mar. 25, 1969, by Bruce D. Jimerson, the contents thereof being incorporated as background information for the purpose of describing prior art locomotion systems.
In recent years the toy manufacturers have put increasing emphasis upon creative toys and games which will promote reciprocal interplay between the participants and the game pieces. For example, in successful action toys like the slot car sets, the speed control provides the means by which the operators transfer their response and emotions to become the daredevil drivers of a miniature race track. In another action gametoy described in the above-referred to patent application, the players manuever their ships by remote control to battle one another on the surface of an artificial ocean. Another type of action gametoy enjoying prolonged commercial success is the vibrational football game in which two different football teams may be lined up by opposing players and the field vibrated so as to move the pieces in a more or less random fashion. In these, and other action gametoys however, the entertainment factor depends to a great extent on the amount of control which the participating players enjoy. Thus, in the case of the slot car, the player can control speed but not direction. In the vibrational football game, after the pieces are initially lined up, their movements are more or less random; neither team having any control over the motions of its pieces relative to the pieces of the opposing player. In the Naval Action Gametoy the players have separate control over their own ships, but only on a limited part of the playing board. Furthermore, as the degree of control is increased, the cost of manufacture rises sharply. Thus, in the Naval Action Gametoy, four separate motors are required to propel two separate and independent X-Y drive systems. Since the cost of manufacturing a plaything is very important in determining its commercial success. a desirable objective of any propelling apparatus of a controllable gametoy is that it be inexpensive.
SUMMARY OF THE INVENTION In accordance with the background information and prior art description, a paramount object of the present invention is to provide a low cost controllable gametoy.
Another object of the present invention is to provide a competitive gametoy having a plurality of moving pieces, each of which may be remotely controlled as to velocity and direction.
A further object of the invention is to provide a competitive race car game wherein each player may separately control the speed and velocity of his own vehicle.
It is another object of the invention to provide a competitive football gametoy wherein each player may remotely control the motion of his own team.
It is another object of the present invention to provide a competitive Naval Action Gametoy wherein each side may remotely control its own fleet on a common playing surface.
It is another object of the present invention to provide a locomotion apparatus which may be used to produce the desired motions and control for any of the above referred to gametoy embodiments and which may also be applied to other devices having as a requirement an inexpensive motion control for propelling a moving object relative to a horizontal surface.
These, along with other objects and advantages of the invention to be gleaned from the detailed description of a particular embodiment given hereinbelow, are achieved by the use of a directional oscillatory plane. The plane (or playing surface area) is arranged so that it may be freely vibrated in any direction parallel with the surface of the plane. The movable objects are of different weights and have different coefficients of friction so that some of the objects (those under the control of a first player) are effected by only one mode of oscillation whereas other objects (those under the control of a second player) are effected only by a different mode of oscillation. As a consequence, each player may separately control his own team, ships, cars or whatever, to move in and about, push around, or chase after the opponents forces. Since each player has complete and full control of his own pieces over the entire playing surface, there are numerous life-like actions which may be simulated on a small scale in a manner not heretofore possible.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a cutaway view showing the playing surface and a portion of the propelling apparatus.
FIG. 2a is a cross-sectional view of the gameboard and drive apparatus.
FIG. 2b shows a throttle detail.
FIG. 3 shows an exploded view of the right side cam assembly.
FIG. 4a shows in detail the location of the cam detents.
FIG. 4b shows how the shape of the cam detents and slots enable registration of the cam lobe opposite to the cam follower protrusion.
FIG. 4c shows a situation where the cam detent is displaced beyond the point where the V-shaped detent can effect registration.
FIG. 5 shows an alternative embodiment employing a push down rotatable knob for steering and throttle control.
FIGS. 6a-6d show pictorially the displacement of the playing surface and object undergoing a vibratory acceleration cycle.
FIGS. 7a-7f show the acceleration, velocity and displacement profiles of the playing surface and object for one complete acceleration sequence.
FIGS. 8a-8e show the acceleration, velocity and displacement profile for the playing surface and the displacement profiles for two objects having different coefficients of friction where the playing surface is subjected to a first vibration mode.
FIGS. 8f-8j show the same quantities where the playing surfaceis subjected to a second vibration mode.
DESCRIPTION OF A PREFERRED EMBODIMENT Adverting to the drawings, and particularly to FIGS. 1 and 2a, a preferred embodiment of the invention comprises a smooth horizontal playing surface 10 which is supported from underneath by a substructure frame 11 having two transverse beams 12 and 13 spaced about one-fourth of the distance from each end of the playing surface, neither of which is attached to the playing surface the playing surface 10 itself is elastically coupled to the substructure frame 11 by tension spring 14-19. Springs 14-17 have an elastic constant of 10 times that of the springs 18 and 19 so as to minimize the rotational motion which would result from applying off center forces to the playing surface 10. Such an arrangement permits the playing surface 10 to be translated in any direction (in an oscillatory fashion) relative to the frame 11 as described below. The frame 11 is preferably of a plastic construction and the playing surface may be either a thin sheet of plastic or metal.
An oscillatory motion of the playing surface is brought about by the revolving cams 22 and 23. The cam 22 is driven by the gear 24 and cam 23 is driven by gear 25. The gears 24 and 25 are located on diametrically opposite sides of the lost motion drive gear 30 which is arranged to have an odd number of sectors of teeth so that only one of the gears (either 24 or 25) may be driven at any one time. The lost motion drive gear 30 is actually comprised of three separate discs, the top disc A having only three sectors of teeth (at iocations 31, 34 and 37) and the middle disc only 6 sectors of teeth (at locations 31, 32, 34, 35, 37 and 38) whereas the bottom disc C has teeth sectors at all of the nine locations (31-39). All three sectors are preferrably made of nylon and are bonded together using any conventional means so as to form the composite gear 30. The motor 40 which drives the gear 30 at a constant speed is preferrably an inexpensive 110 volt 60 cycle AC induction motor similar to the type used in inexpensive household items, although it will be understood that any type of device capable of producing a reasonably constant rotational speed may suffice for this purpose.
When the motor 40 is energized, the lost motion gear 30 is caused to rotate at a constant speed. The playing surface 10 can then be moved in an oscillatory fashion by lowering either (or both) of the gears (24 or 25) on its respective bearing post (41 or 42) until the teeth of the lost motion gear 30 are engaged. For example, assume that the throttle handle 43 is moved downwardly in the direction of the arrow 45 so as to compress the bottom portion of the compression spring 47. (This is accomplished as shown in FIG. 2b by making the slotted opening 49 of the throttle handle wide enough to accomodate the diameter of the bearing post 41 but not lower compression spring 47.) When the bottom portion of the lower compression spring 47 is thus compressed, the upper compression spring 50 functions to move the cam follower 26 (together with the cam 22 and its attached gear 24) downwardly on the bearing post 41. If the throttle lever 43 is depressed only part way so that the gear engages only the teeth of the A disc, only three oscillary cycles will be transmitted to the playing surface for each revolution of the gear 30. If however, the throttle 43 is depressed further, the gear 24 will move to engage the teeth of both the A and B discs so that six oscillary cycles are transmitted for each revolution of gear 30. Similarly, with the throttle fully depressed nine oscillatory cycles result. Since (as will be explained below) each oscillatory cycle results in a fixed increment of movement of the object under control, the velocity of propogation of the controlled object will be directly dependent upon the vertical location of the gear 24 with respect to the lost motion gear 30. The member 43 is thus properly termed a throttle lever in that it may be varied to increase or decrease object velocity.
In order to understand the arrangement for controlling the direction, reference may be had to the exploded view of the cam assembly shown in FIG. 3. When the gear 24 (and its intergally attached cam 22) is lowered on the bearing post 41, the teeth of the lost motion gear intermittently engage the teeth of the gear 24 causing the cam to make one complete revolution for each engaged sector of teeth on the lost motion gear 30. The rotatable cam follower 26 will experience one cycle of translatory movement for each rotation of the cam 22. The direction of this translational vibration will depend upon the position of the cam follower protrusion 62. As the cam follower 26 is rotated via the steering wheel 63, the position of the cam follower protrusion 62 changes so that the direction of vibration also changes. The cam follower 26 is arranged so that it may continuously rotate within the cylindrical shell 64, the latter being rigidly attached to the underside of the playing surface 10. The outside diameter d of the bottom part of the cam follower 26 is made slightly smaller than the inside diameter d i of cylindrical shell 64 (slip fit). This allows the cam follower 26 to be rotated with respect to the cylinder 64 (to change the vibration direction) or to slide axially with respect to the cylinder 64 when the throttle 43 is moved to vary the velocity. The translational motion of the cam follower 26 is transmitted to the wall of the cylindrical shell 64 which in turn vibrates the playing surface 10.
The compression springs 50 and 47 cause the cam 22 and cam follower 26 to remain together (with the cam 22 inside of the cam follower cavity irrespective of the throttle position. Thus, as the throttle arm 43 is lowered, the spring 50 drives both the cam 22 and cam follower 26 downwardly on the bearing post 41. When the throttle arm is raised, the cam 22 and cam follower move up together. The length L" of the cam follower is made such that the cam gear 24 just clears the top of the lost motion gear 30 when the top turret part 65 of the cam follower contacts the underside of the playing surface 10, provided that the cam 22 and cam follower 26 are rotationally aligned so that the detent flanges 66 and 77 on top of the cam are juxtaposed to the detent slots 68 and 69 on the inner end of the cam follower cavity 70. This assures that the cam lobe 61 is properly registered with respect to the cam follower protrusion 62 for the next rotational cycle.
The importance of registering the cam lobe 61 relative to the follower protrusion 62 lies in the dynamics of the locomotion principle to be explained below. At this point it will be sufficient to say that the cam lobe 61 must come to rest exactly opposite the follower protrusion 62. If, for example, there were no detent arrangement and the throttle were lifted upwardly at a time when the cam gear 24 was being driven by the lost motion gear 30, the teeth of the gear 24 might disengage the teeth of gear 30 leaving the cam lobe 61 at any arbitrary position with respect to the protrusion 62. Because of the detents however, gear 24 will not clear the teeth on the upper disc A of gear 30 until the cam lobe 61 is opposite the protrusion 62 so that the detents 66 and 67 occupy the detent slots 68 and 69 respectively. As shown in FIG. 4a, the detents (as well as the detent slots) are located at slightly different radial distances so that there is only one mating position. Thus, with the throttle lever 43 in the up position, the teeth of disc A will continue to drive the cam gear until it is rotated to a point where the detents 66 and 67 register with the slots 68 and 69, at which point the spring 47 functions to raise the cam gear beyond the influence of the gear 30; the relationship between the cam lobe 61 and the cam follower protrusion 62 being preserved irrespective of the angular position of the protrusion 62. It will be noted that the detents are V- shaped so as to facilitate catching the slots even though the cam lobe 61 is not exactly opposite the protrusion 62. This permits directional change to be made via the steering wheel while the cam is being intermittently drive by the toothed sectors of gear 30. Since the angular rotation of the steering wheel 63 will normally be much less than the angular speed of the cam, the slight error resulting from the angular displacement of the cam follower due to steering while the cam gear 24 is engaged by the gear 30 may be compensated for by the V-shaped detents. Thus, as shown in FIG. 4b, even though the detent 67 is not perfectly positioned with respect to the complementary slot 69, the spring forces on the two members cause the detent 67 to slide along the ramp 90 of the slot 69 until complete accordance is reached. If, however, due to some peculiarity the detent 67 is too far out of position (as shown in FIG. 4c) when the cam gear 24'cornes to rest after an oscillation cycle, the throttle handle 43 may be raised all the way to allow disc A to drive the cam gear to registration as described above.
Rotation of the cam follower to effect directional changes is accomplished by turning the wheel 63 in the desired direction. The wheel 63 is attached to the hollow steering shaft 72 by a pin 73 through accordant holes 74 and 75 in the wheel hub 76 and steering shaft 72 respectively. The inner diameter d of the hollow shaft 72 is made slightly larger than the diameter of the bearing post 41 (to provide a slip fit). The wings 77 and 78 on the steering shaft 72 function to engage the slots 79 and 80 on the guide turret 65 of the cam follower 26. In order to avoid impairing the free transfer of energy from the cam 22 to the playing surface 10, it is important to isolate both the playing surface and cam follower from any contact which would be detrimental. For this reason, the inside diameter of the turret 65 is made approximately 3/16 of an inch larger than the outside diameter (1:, of the steering shaft 72. Similarly, the slots 79 and 80 are made both wider and deeper than the corresponding dimensions of the wings 77 and 78. The width over size should not, however, be large enough to produce a noticeable play or loseness in the steering characteristics of the apparatus.
The steering wheel 63 may be rotated to change the oscillatory orientation at any time, whether or not the cam gear 24 is being driven by the lost motion gear 30. As was explained above, the speed at which the steering changes are made is usually much less than the angular velocity at which the cam is rotated by the gear 30. Hence, under normal operating conditions, registration between the cam 24 and cam follower 26 will be established by the complimentary V-shaped slots and detents even if the cam follower 26 is angularly displaced a small amount during a rotation of the cam. As shown in FIGS. 2a and 3, the pin 73 serves the dual function of connecting the hub 76 of the steering wheel 63 to the steering shaft 72, and in addition, it prevents the steering wheel from being depressed by virtue of its contact with the top of the bearing post 41. For race car and boat manuvering games and the like, the steering wheel 63 throttle lever 43 combination is idea]. If the playing surface is used to propel objects which are not normally steered with a wheel (e. g. miniature football players) it may be desirable to use a different control motif such as a rotatable push down knob which will function to vary both speed and direction. The present embodiment may be easily adapted to this end by unscrewing the throttle handle 43 and replacing the steering wheel 63 with the spring loaded knob 96 shown in FIG. 5. The inner wall 94 of the knob shaft is adapted to have a small groove 98 which accomodates the flange 95 on the steering shaft 72. The knob 96 may thus be rotated to effect direction changes or pushed down to increase velocity, the inner spring 99 functioning to depress the steering shaft and cam follower in proportion to the downward force applied.
It will be understood that the explanation of the right side cam assembly is equally applicable to the left side cam assembly (i.e. parts 23, 25, etc.). The only difference between the two assemblies lies in the shape of the cams themselves. In order to understand the reason for this difference and how it can be used to produce a separate and independent control of different objects on the same playing surface, it is necessary to consider the dynamics of the locomotion principle which lies at the root of the invention.
Referring now to FIG. 6a, the locomotion principle may be understood by considering the effect of a translational displacement of the playing surface 10 relative to a movable object 100. If the coefficient of frinction between the playing surface 10 and object 100 is u then the maximum horizontal force which the playing surface can exert on the object is where M is the mass of the object and g is the gravitational acceleration, namely 32ft/sec Since force is equal to mass times acceleration, the maximum horizontal acceleration of the object 100 (due to movement of the playing surface 10) is Max Acceleration F max/M Hence, no matter how fast the playing surface 10 is moved, the object acceleration is limited to n times the gravitational acceleration. Thus, for a friction coefficient u 0.5, the object 100 will move with the playing surface 10 when the playing surface 10 is accelerated below 0.5g. When the playing surface 10 is subjected to horizontal accelerations greater than 0.5g, the object 100 will slide with respect to the playing surface 10. When the playing surface is first subjected to a horizontal acceleration less than 0.5g in one direction, and then brought back to its original position by an acceleration greater than 0.5g, the final position of the object 100 is a displacement relative to the playing surface. For example, assume that the playing surface 10 is subjected to an acceleration of 0.5g in the direction of the arrow 101 and then brought to a stop by a 1.0g acceleration in the direction of the arrow 102. FIGS. 6b and 60 show pictorially what happens to both the object 100 and the playing surface displacements. In FIG. 6b (during the 0.5g acceleration) the object 100 moves the same distance forward (in direction of the arrow 10]) as the playing surface 10. When the 1g acceleration in the opposite direction is applied, the object 100 (whose velocity is the same as that of the playing surface 10) cannot slow down as fast as the playing surface 10. Hence the object 100 slides with respect to the playing surface 10 so that when both the object 100 and the playing surface 10 come to rest, the object 100 is displaced with respect to its initial position on the playing surface. If the playing surface is then returned to its initial location in a manner which does not result in accelerations which would cause the object 100 to slide on playing surface 10, the complete sequence will result in the object 100 being displaced on the playing surface 10 a distance X I 1 as shown in FIG. 6d.
In a preferred embodiment-of the invention, the duration of the various movements of the playing surface l would be adjusted so as to return the playing surface to its initial position with zero velocity, but with the object 100 displaced. The sequence can then be repeated to produce a further displacement of the object 100 and so on, with the average velocity of the object being dependent upon the number of vibration sequences per unit time. For example, if each sequence caused the object 100 to slide 1/10 of an inch, and there were 10 sequences per second, the average velocity of the object 100 relative to the playing surface 10 would be 1 inch per second.
FIG. 7a shows a plot of an acceleration sequence which may be used to vibrate the playing surface 10 so as to return it to its initial position with zero velocity. Assuming again that p. 0.5 so that the object 100 does not slip with respect to the playing surface during the initial acceleration of 0.5g, both the playing surface 10 and object 100 will acquire a velocity of:
7 111 a dt 0.5 32 ti /i4 8 121m/n 4 10- sec) 7.7 in/sec as shown in FIG. 7b. During the second part of the sequence (from 70 5 t 5 110) the playing surface will acquire a velocity v due to the negative acceleration a,, the value of which is:
110 v =7.7 in./see.f a dt Finally, during the period 110 t S 150, a final velocity v results:
In FIG. 7c, the displacement of the playing surface is shown as a function of time. Thus, at time t 70, the playing surface will have moved from its initial position a distance:
= (0.5) (32 ftlsec (4 l0' sec) 12 in/ft =0.l53 inches at time t= 110, the playing surface will have moved to the point (0.5) (32 ft/sec (4x10 sec) 12 in/ft 0.153 in (2X10 ft/sec) (4X10 sec) l2 in/ft =0.l53 inches and, at time 1 =1 50, the playing surface will have come to rest at the point S3 S2 +1/2dyt Ngt =O.l53 in+0.l53 0.306in 0 FIGS. 7d, 7e and 7f show the acceleration, velocity and displacement of the object for the same time intervals. Thus, during a time 30 E t S the object 100 does not slip with respect to the playing surface. Hence, at t= 70, the object 100 will have travelled the same distance as the playing surface 10 so that X 0.153 inches. During the time 70 E t 5 110, the inertia of the object causes it to continue moving even though the playing surface is brought to a stop (at t The force acting on the object is uM, so the negative acceleration is F/M ,umg/m. Since this is the same as the acceleration a,, the object will simply slide forward a distance equal to that travelled during the time 30 S t S 70. Hence, during the time 70 5 t 5 I10, the object 100 moves to the point X for a total displacement of 0.306 in. Finally, during the time 1 l0 5 t S 150, the object moves backwards as a consequence of the negative velocity of the playing surface 10 during this time interval. However, since the velocity of the playing surface 10 is increasing from the time t 1 l0 to t= 150, there is a cross-over point P (at F) where the object 100 catches up to the velocity of the playing surface. From this point on, the playing surface 10 exerts a force on the object 100 which tends to increase its velocity as shown in FIG. 7e. When the playing surface comes to rest at t the object will wind-up with a resultant displacement X which may be calculated as follows:
= 0.306 (16 ft/sec (20 X 10 sec) 0.23 inches It will thus be observed that for the type of acceleration waveform shown in FIG. 7a, the resulting displacement X of the object 100 relative to the playing surface is equal to the magnitude S of the board vibration.
It will be understood of course, that the numerical example given is by way of illustration only. If such a sequence of acceleration intervals were actually employed, the maximum velocity obtainable can be estimated by multiplying the maximum number of vibratory sequences per second times the average resultant displacement per vibratory sequence. Thus, in this example, each sequence consumes 120 millisec. Hence, the maximum velocity is 1000 millisec.
= 1.92 inches/sec.
In most gametoy applications, scale velocities on the i order of 0.3 to 0.8 inches/second are entirely adequate. In these cases it is desirable to use a shorter vibration cycle duration in order to decrease the magnitude of 3/2 (32 ft/sec") (2 X sec l2 i ft) =0.l 14 inches I FIGS. 8a 8] illustrate how the above principles apply to the gametoy locomotion apparatus illustrated in FIGS. 1-5 so that opposing players may exercise independent control over different objects on the same playing surface. FIGS. 8b and 8c show the velocity and displacement profile of the playing surface when subjected to the acceleration sequence shown in FIG. 8a and FIGS. 83 and 8h show the velocity and displacement profile when the playing surface is subjected to the acceleration sequence shown in FIG. 8f.
Referring now to the acceleration sequence of FIG. 8a, the corresponding displacement of an object (No. l) on the playing surface having a coefficient of friction p. a g is shown in FIG. 8d and FIG. 8e shows the corresponding displacement of a second object (No. 2) having a coefficient of friction 4a,,,,,. Object No.1 thus behaves in a manner identical to that shown in FIG. 7f, moving with the playing surface during that part of the cycle where the frictional force pMg is equal to the inertial force Ma and slipping with respect to the playing surface when the latter is subjected to acceleration components which exceed the frictional forces. Object No. 2, having a frictional force greater than the maximum inertial force to which the playing surface is subjected during the cycle shown in FIG. 8a, does not slide with respect to the playing surface. Hence, the displacement curve (FIG. 8e) of the object 0,, is identical to the displacement curve of the playing surface (FIG. 80). When the playing surface comes to rest at the end of the vibration cycle, the object 0,, is exactly where it was at the beginning of the cycle. Hence, the acceleration sequence shown in FIG. 8a will effect only the object No.1 and not the object No.2.
Consider next what happens to each object when the playing surface is subjected to the acceleration sequence shown in FIG. 8f. Object No. 2, having a frictional force equal to 4a moves with the playing surface during the first part of the vibrating cycle, and then slips when the playing surface is subjected to greater acceleration. The profile shown in FIG. 8j is therefore identical with that shown in FIG. 7f except that the time scale is compressed. The Object No.2 is thus displaced by the vibrating cycle shown in FIG. 8f but not by the vibrating cycle shown in FIG. 8a.
FIG. 8i shows the spurious displacement of Object No.1 as a consequence of the acceleration cycle shown in FIG. 8]". Since Object No.1 slips during the entire acceleration sequence of FIG. 8f, and since the duration of the vibrating cycle is only a that shown in FIG. 8a, the resultant cross coupling error E is relatively small (about percent in the case illustrated). This slight infiuence of the acceleration cycle shown in FIG. 8f can be easily compensated for by the contestants, or it can be reduced even further by slightly modifying the acceleration profile shown in FIG. 8f. Even if no compensation is employed, it will be evident that for the practical purposes of a gametoy, the slight cross coupling error can be ignored and in essence, the acceleration profile shown in FIG. 8a will motivate only Object No.1 and the acceleration profile shown in FIG. 8f will motivate only Object No.2. Hence, if the direction of the acceleration components shown in the sequences of FIG. 8a and the repetition rate of such sequences are under the control of one player, and the direction of the acceleration components shown in the sequence of FIG. 8f and its repetition rate are under the control of a second player, the first player will be able to command the speed and direction of objects having one coefficient of friction and the second player will be able to command objects having a different coefficient of friction, so long as the two sequences do not occur simultaneously.
Referring once again to FIGS. 1 and 2a, it will be seen that the cam gears 24 and 25 are positioned opposite one another, and the lost motion gear 30 is arranged to have an odd number of toothed sectors. This arrangement assures that the playing board 10 is time shared so that vibratory cycles do not occur at the same time. Thus, if both players have their throttles fully depressed, there will be 18 cycles for each revolution of the lost motion gear 30. Nine of these will effect objects with one frictional coefficient and nine will effect objects with a different frictional coefficient. If the time duration of the longest cycle is 60 milliseconds and the vibrating amplitude is 0.1 inches, the maximum velocity of an object under the command of either player is H2) (1000 millisec/60 millisec) (0.1 inch) 0.83 inches/sec In the example given above (with both players operating under full throttle), the playing surface is equally time shared. When one of the players reduces speed by lifting the throttle, one of the cams will not be engaged nine times for each revolution of gear 30. There may thus be more of the short duration cycles or more of the long duration cycles, depending upon which player is commanding a higher velocity.
In order to generate the acceleration profiles shown in FIGS. 8a and 8f, the earns 22 and 23 must be shaped so that, when driven at constant angular velocity by the gear 30, the resultant displacement of the playing surface (as of function of time) will be as shown in FIGS. and 8h respectively. It will be evident that for a constant linear velocity, the displacement shown in FIGS. 80 and 8h will result from a cam lobe having exactly the same shape. Thus, for a constant angular velocity, the cams 22 and 23 will have radial displacements equal to the corresponding linear displacements shown in FIGS. 8c and 8h.
The importance of registering the cam lobe with the follower protrusion can now be appreciated. If the acceleration sequence were to start at some arbitrary point (e.g. t= 50 in FIG. 7a) the resultant displacement of the object X would be completely unpredictable. The detents 66 and 67 together with the slots 68 and 69 thus assure that the cam lobe 61 begins and ends opposite the protrusion 62. When the cam gear 24 is engaged by a sector of teeth on gear 30, it is thus turned one complete rotation, the protrusion 62 being displaced in accordance with the profile shown in FIG. 7c as the cam lobe 61 rotates. Since the outside of the cam follower 26 is in contact with the cylinder 64, the protrusion displacement is transferred to the playing surface.
Where higher translation velocities are desired, the object may be designed to have directional frictional characteristics which allow them to slip freely in one direction with respect to the playing surface, but not in another. in most applications, and even those involving miniature cars, locomotion velocities in the range of l inch/second are adequate. Since the cars are not in slots, but are steered around curves and obstacles, control becomes difficult at greater speeds. Where the apparatus is used to propel football players it is advantageous to make the objects having a low coefficient of friction heavier than the objects having a high coefficient of friction in order to balance the blocking characteristics of each team.
Different coefficients of friction are easily obtained by making the contact base of the objects from different materials (e.g. plastic and rubber). It will be understood also, that the basic concept of the apparatus may be extended to more than two different types of objects. Thus, three different cams could be used having progressivly shorter acceleration sequence durations. This would be desirable, for example, in' controlling the ball carrier separately from the other members of the team or to control three separate miniature cars, etc. Thus, although a preferred embodiment of the present invention has been shown and illustrated, it will be understood that the invention is not limited thereto, and that numerous changes, modifications and substitutions may be made without departing from the spirit of the invention.
l. A locomotion apparatus comprising:
a horizontal playing surface;
vibration producing means for steering slidable objects on said horizontal playing surface comprising means for oscillating the entire playing surface in a single direction parallel to the plane of said playing surface; and
means for controlling the azimuth direction of the oscillation of said playing surface without changing the azimuth orientation of the playing surface.
2. The locomotion apparatus recited in claim 1 wherein said vibration producing means comprises:
means for producing an acceleration in one direction and a subsequent acceleration of a different magnitude in the opposite direction; and
means for controlling the duration of each of the accelerations to bring said playing surface to rest after said playing surface has been accelerated at least once in each direction.
3. The apparatus recited in claim 1. wherein said vibration producing means comprises:
means for cyclically applying a first magnitude aeceleration to said playing surface in one direction followed by a second magnitude acceleration to said playing surface in a direction opposite to direction of the first acceleration;
means for controlling the number of vibratory cycles per unit of time whereby the average velocity of slidable objects resting upon said playing surface may be varied.
4. The apparatus recited in claim 1 wherein said vibration producing means comprises:
a first vibrating means for displacing and returning said playing surface so that objects having a first coefficient of friction which are resting on said playing surface will be displaced relative to said playing surface by said first vibrating means, but
not objects having a second coefficient of friction;
a second vibrating means for displacing and returning said playing surface so that objects having a first coefficient of friction will not be materially affected by said second vibrating means whereas objects having a second coefficient of friction which are resting on said playing surface will be displaced by said second vibrating means;
means for time sharing said first and second vibrating means so as to prevent the vibrations from occuring simultaneously.
5. The apparatus recited in claim 4 wherein is included:
means for independently controlling the repetition rate and direction of said first and second vibrating means whereby both the velocity and direction of objects having different coefficients of friction may be independently varied.
6. The apparatus recited in claim 5 wherein said vibration producing means comprises:
a lost motion gear driven by said motor, said lost motion gear having an odd number of toothed sectors;
diametrically opposed cam gears arranged to be moved to engage the sectors of said lost motion gear;
a first cam attached to one cam gear;
a second cam attached to the other cam gear, said first and second cams to be shaped to produce different acceleration cycles;
a cam follower in contact with each cam and in contact with said playing surface whereby said playing surface can be vibrated by both cams when said motor is energized.
7. The apparatus recited in claim 6 wherein said lost motion gear comprises a plurality of layers each having a different number of toothed sectors; and
means for moving each of said cam gears independently to engage or disengage the toothed sectors of difi'erent layers of said lost motion gear whereby the number of vibratory cycles per unit time produced by each of said cams may be varied to effect independent velocity control of objects having different coefficients of friction.
8. The apparatus recited in claim 6 wherein is included a means for independently rotating each of said cam followers relative to their respective cams to change the direction of vibration of said playing surface whereby the direction of travel of objects having different coefficients of friction may be independently controlled.
9. The apparatus recited in claim 6 wherein said lost motion gear comprises a plurality of layers each having a different number of toothed sectors;
means for moving each of said cam gears independently to engage or disengage the toothed sectors of different layers of said lost motion gear whereby the number of vibratory cycles produced in a given time by each cam may be varied to effect independent velocity control of objects having different coefficients of friction; and