CA2129196A1 - Rocking board - Google Patents

Abstract

The present invention relates to a totally new kind of skateboard, which has a means to propel forward utilizing a rider's motion and transfer of weight, without using the foot to push the board off the ground.
This is accomplished by incorporating a see-saw system on the skateboard where the rider applies his motion and weight to the see-saw board. The small pivot arc produced at the fulcrums is expanded into a larger one by a leverage multiplier. By the use of clutches the arc travel is then converted through a shaft rotation, a combination of sprockets and onto the propelling wheel.
The new skateboard is propelled by rocking the board and is fun use. It is super exercise for the legs. It can transfer a rider a short distance and still can perform regular skateboard activities.

Description

-ROCKING BOARD

The present invention relates to a new type of skateboard that does not require foot movement pushing off the ground to propel the board but rather has a means to propel by intentionally utilizing a rider's motion and transfer of weight onto the rocking board.
Construction of early skateboards were made of wooden boards and steel wheels. Until recent years, skateboarding was a very popular form of entertainment among young people.
Today, skateboard improvement include board made of fibre glass and reinforced resin for lightness and resiliency, wheels made for low friction with urethane rollers, low audible noise and accurate tracking with control. Most high tech skateboards are used by professionals for competition on skating rings. But the general public uses their skateboard on naturally slope pavement or on normally smooth paved streets. Others use them for straight riding to transport themselves a short distance. The main features to this present invention encompasses all the thrills of skateboarding and is run totally by body control of motion and weight, to give even more excitement. There have been many proposed designs to upgrade the skateboard but most are concerned with the improvement of driving mode and maneuverability.
One design is by Robert B. Armstrong's skateboard, patent number 4,795,181 issued on January 3, 1989. This proposed a skateboard comprising of a sin~le oversized centrally located 21~9196 wheel in addition to conventional pairs of front and rear wheels. The wheels are arranged so that the board will ride on three wheels simultaneously either the front or the rear. At a sufficient speed and balance the inventor claimed that the rider may be able to roll on just the single centre providing maximum challenge and maneuverability.
Another design is by Paul S. Runyan, Jr., with the patent number 4,029,330 issued June 14, 1977, which proposed a cambered skateboard provided with longitudinally adjustable truck assemblies. The tracks, being rigid, reinforced the camber of the board in addition to providing a plane support for the movable truck assemblies. By narrowing the board at one end over a truck, torsional flexibility would modify the turning characteristics of a particular board.
The present invention has a propelling wheel with a diameter close to four times larger than the skateboard rollers, positioned along the longitudinal centre of a four roller installation in a rectangular format as seen on a standard skateboard. The wheel revolves with an axle and has a small side sprocket driven by an endless chain from a larger sprocket. This larger sprocket is in one shaft with two one way clutches each positioned on either side of the propelling wheel. This propellin~ wheel is sandwiched by two parallel levers with a board at each end which will act as the see-saw for the skateboard propelling system. When the see-saw platforms move up and down, a small pivot arc is produced at 21291g6 the fulcrums. This arc is expanded into a larger one by a leverage multiplier and onto the clutches which will further convert the arc travel into a shaft rotation, and to a combination of sprocket that will power the propelling wheel.
The two pairs of rollers serve as a mechanism carrier and touch the ground one after another. Their main function i5 to counter-act the reaction force delivered by the platform's pressure direction. The front rollers also contribute to slight directional turns when the user shifts his lateral weight. The back rollers can be used to lift the forward end for acrobatic action, 180 degree turns and for dragging the brake.
At this point it is appreciated that body motion and transfer of weight from the feet to the rocking boards create a tremendous force at the see-saw fulcrums. There are friction losses through the mechanical power train but there is definitely power remaining to propel the Rocking Board.
Further features and advantages will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:
Figure 1 is the perspective view observed at the right back end embodying the present invention.
Figure 2 is the top view of the new skateboard, with an arrow at the boards showing the propelling direction. It also shows the cutting sections of A-A, B-B and C-C.

Figure 3 i5 the side view of the present invention showing the relation of see-saw leverages and the board to the roller carrier.
Figure 4 is a sectional view taken along line A-A of figure 3 showing the propelling wheel related to the frame construction.
Figure 5 is the cross sectional view taken along line B-B
of figure 3 showing the pivot support of the see-saw lever and the arrangement of the leverage multiplier in relation to the mechanism carrier frame.
Figure 6 is the cross section of the see-saw lever and mechanism carrier frame taken along line C-C to show their construction and relation to other binding parts.
Figure 7 is the enlargement of the left cross-sectional see-saw lever, the binding parts and the support which emphasize the attachment of the left initial power lever. The figure represents the enclosure of the dotted rectangular box D respective to the cross-section of figure 6.
Figure 8 is the enlargement of the right cross-sectional see-saw lever, the binding parts and the support to emphasize the attachment of the right initial power lever. The figure represents the enclosure of the dotted rectangular box E
respective to the cross-section of figure 6.
When referring to the drawings the reference number 10 generally designates the Rocking Board device embodying the present invention. When looking at the arrow sign on the 2129191~

platforms, with the arrowhead pointing directly to the viewer, the viewer's right side designates right hand characteristics while the viewer's left hand side designates left hand characteristics, respectively. The propelling wheel 1 is held in position by an axle 2 best depicted in figure 2 which fastens in a longitudinal and centered manner to the side frames 3 and 4, construction of which is best seen in figure 4. These side frames have their sides parallel and upward so that the bottom ends fasten to the cross binder 5 and 6. The cross binder ends are then screwed perpendicular to the mechanism carrier lever 7 and 8. The end pieces of the mechanism carrier lever 7 and 8 are connected across to the flat binder 9 and 10 which has a centered inclined plain 11 on its forward portion where the roller's slight turn mechanism 13 is screwed and the rearward inclined plain 12 where the brake pad 14 is attached. Axle 15 for rollers 16 and 17 is attached to the straight rear end portion of mechanism carrier lever 7 and 8 before bending upward to the inclined plain 12.
Roller 15 in relation to the rear end positioning to the mechanism carrier frame 8 is best observed in Figure 4. It will be noticed that the slight turn mechanism 13 of rollers 18 and 19 is attached in an angle to the inclined plain 11 to allow for turning efficiency and to elevate rollers 18 and 19 off the ground approximately 3/8 of an inch when propelling wheel 1 and allows rollers 16 and 17 contact with the ground as best shown in figure 3. These wheel contacts to the ground will change their provision of setting when the operation is explained in the later chapter. It is to be added in this explanation that the placement of the driving wheel axle 2 across the mechanism carrier lever is approximately 40 %
closer to the back rollers 16 and 17 and approximately 60 %
further to the front rollers 18 and 19.
Looking at the top view of the present invention on figure 2, there are two platforms 20 and 21 held together by two levers 22 and 23 in a square and in line with the mechanism carrier lever 7 and 8. Lever 22 and lever 23 have their respective cradle 24 and 25 which are positioned approximately midway to the levers. Looking at figure 7 and figure 8, cradle 24 and cradle 25 have an undercut to accept lever 22 and lever 23 (shown in cross section) in a snug fit.
The cradles' undercut depth is less than a few thousandth to the thickness of the levers so that the three securing bolts for each cradle can apply their washer pressure to the outside surface of their respective lever. This is the levers's point where the bending effect peaks and is caused by human weight application to the platforms. The cradles are designed to hold the levers free from holes and cuts yet it is adjustable in leverage distance to accommodate for moment changes. Cradle 24 and 25 have fulcrum shafts 26 and 27 positioned centered and perpendicular to the cradle's plain located at approximately 5/16 to the shaft centre at the bottom surface of levers 22 and 23 and is held in position by set screws 29 and 30 respectively as seen in figures 7 and 8. The outside ends of shaft 26 and 27 pivot in a bushing supported by brackets 30 and 31 respectively, while the inside ends pivot and are supported through a hole with a bushing located at driving wheel side frames 3 and 4. Fulcrum shafts 26 and 27 are vertically aligned but lower in position to the propelling wheel axle 2 which can be observed in figure 4. The reason for the fulcrum shafts positioned in a lower placement relative to the propelling wheel axle allows the rider a more comfortable step approach to the platform throw from the ground. Based on the working model, the size of the propelling wheel 1 is 9 inches in diameter and therefore the axle 2 centre is 4 and 1/2 inches from the ground. Using 4 and 1/2 inches as a height of the fulcrums from the ground would give the Rocking Board an unstable design and an uncomfortable step approach to the platforms for the ride. This device has two fulcrum shafts placed on both sides of the propelling wheel 1 to lower the fulcrum height to the ground. The actual working model has the fulcrum shaft's centre 3 and 3/8 inches from the ground and 1 and 1/8 down from the driving wheel axle 2 and from their shaft centres. From this discussion it is evident to conclude that a see-saw is incorporated to the rocking board which eventually will drive the propelling wheel.
Returning back to the device platforms, the top view in figure 2 shows the forward platform 21 designated with the arrowhead while the rear platform 20 has the tail. This 212~1~S

indicates to the rider the direction of the propellinq motion.
This also clarifies that the device can only go in a forward direction. The rider can stop on an average ground slope or grade without slipping back provided he steps either on one of the platforms in a collapse stroke. Referring to figure 2 and 3, the platforms have an equal flat surface area, but the forward platform's 21 leading edge is less than the rear platform's 20 trailing edge surface area. It can be observed in figure 3 that the placement of the rear platform's 20 flat surface area is 2/3 in advance over the centre of roller 17, for the purpose of; when the foot shifts over on the trailing edge surface area on the collapse stroke of platform 20, the entire front including the propelling wheel 1 lifts up and hangs in the air by pivoting to the rollers 16 and 17 and the maneuverability of the device reaches an optimum. The flat surfaces of the platforms including the leading and trailing surfaces are covered by sand aggregates 19 and allows for better contact between the rider's shoes and thereby giving excellent control over the Rocking Board. The bottom surfaces of the leading and trailing edges of platforms 11 and 12 ride and sit nicely over their respective incline plains 11 and 12 at the platform's collapse stroke, which add to the streamline looks of the Rocking Board.
It is aforementioned that the propelling wheel 1 is propelled by a power train deriving from the rider's motion and an intentional transfer of weight. This motion and weight 21~919~

is then transferred to the front and rear platforms through the left and right foot or right to left according to the rider's stride preference. One power stroke develop when a platform is at its highest position and the rider steps down to create a collapse stroke. Since there are two platforms, there are two opposite power strokes created when the see-saw goes up and down. The power analysis of a see-saw leverage is obtained from a step down stroke, while another lever coming from the fulcrum counter- acts the forces otherwise the whole device will just tumble in the direction of the platform in motion. This is where the mechanism carrier levers 7 and 8 are very important. Their strength in materials is as strong as that of the see-saw lever. The length of carrier lever 7 and 8 from the fulcrums to the front rollers or from the fulcrums to the back roller is longer than the see-saw levers and promotes stability in pumping the platforms. The pumping efficiency of the platforms is best attained when that platform starts from its highest height, wherein the opposite platform is fully lowered; and then is depressed to its lowest point, meanwhile the opposite platform now rises to the up position. Though in actual operation platform strokes or height are not measured, just depressing any platform in a high position causes the Rocking Board to react. It can be noticed in figure 3 that there is a solid line for the see-saw, the mechanism carrier lever and their designated rollersin comparison to a dotted line equivalent. This figure , 2l29l9~

illustrates what levers are at work or have just finished a stroke, and how the rollers at the opposite end are definitely raised upwards. It has been said that the height of a platform drops correspondingly in an inclined plain depicting the see-saw efficiency. Whichever platform is under pressure,corresponding carrier lever rollers are always in contact with the ground while the opposite carrier lever rollers are up. If the rider decides to shift his weight to the opposite platform spontaneously, that opposite carrier lever roller has to contact the ground before an effective platform pumping is carried out. For reason of efficiency, the hopping rollers bottom surfaces will be no higher on flat ground than 3/8".
There is no occurrence when all five wheel are in contact with the ground, otherwise the propelling wheel loses its grip to propel the Rocking Board. The difference in forces developed from the see-saw lever and the corresponding carrier lever will be found at the fulcrums. Power levers 32 and 33 attached to cradle 24 and 25 and to fulcrum shafts 27 and 28 respectively, initiate this fulcrum power to the power train located on both sides of the driving wheel.
The see-saw mechanism create two opposite types of power.
If one side of the see-saw is delivering power, the other side is in a relax mode and vice versa. But with the aid of two one way clutches, these relax and working motions are converted into one directional shaft rotation to continuously drive the propelling wheel into a forward motion.

An example of the side power train is seen in figure 5 taken from section line B-B of figure 2, where the arrangement of leverages belongs to the left side of the driving wheel 1.
This power train works when the rear platform is depressed from its top to bottom position. The flow of motion is traced when a force, designated by an arrowr depresses the see-saw lever down. Assuming the mechanism carrier lever 8 is supported up by roller 17, represented by an upward arrow, cradle 26 will sway clockwise from its fulcrum shaft 27. Power lever 32 has its midway length bolted to the upper body of cradle 26 and the pivot point positioned at the fulcrum shaft 27. It is evident that the top end of the power lever 32 will arc to sway in the direction of cradle 26. Attached to the end of power lever 32 is a chain (bicycle size) connected to the short lever of dual lever 35. Dual lever 34 has a portion with a larger body to accommodate a bearing/bushing to revolve at axle 35.
The following recognition paragraph will review the power flow route. If the cutting plain of figure 5 is turned in a 180 degree angle, this allows section parts to rejoin their full length size. Axle 36 is rigidly attached to side frame 4 and unto the side frame 3, as best observed in figure 2. Shaft 37 on the other hand, is at the opposite top end of side frames 4 and 3, installed to rotate parallel to axle 36.
Fulcrum 27 rejoins its cut off length at side frame 4 and the cut off crosses frame 5and6 to theirrespectiveadjoiningparts.

2129lg6 The top end of the dual lever 35 has another piece of chain (bicycle size) running to sprocket 39 and wrapping around at approximately 1/2 of its circumference. The chain after wrapping the sprocket, has extra links wherein the end is attached to an extension spring 43. This spring 43 is routed and aligned to the chain infeed and sprocket for the purpose of free binding operation. The end of spring 43 hook to point 45. Sprocket 39 is attached to a one way clutch. The one way clutch de~ignate that one rotation is running while the opposite rotation is locked. The clutch used in the present invention is called a freewheel for bicycle use. The brand is DICTA, manufactured by Lida Machinery Co. Ltd R.O.C., size 1/2 x 3/32 x 14T. The hub of clutch 41 is attached and keyed to shaft 37, which belongs to the left power train and is driven by the back platform 20r has a sprocket free run opposite to the rotation of the propelling wheel 1 or the lock rotation within the rotation of the propelling wheel 1. The right hand side of the propelling wheel 1, is a large sprocket 46, placed and keyed to shaft 37. A small sprocket 47 is attached to the side centre hub of propelling wheel 1, and is aligned and driven by the big sprocket 46 by an endless chain 48. Meanwhile, there is another power train on the right side of propelling wheel 1, which is driven by front platform 21. The operation of leverages and the one way clutch 40 are the same as the left-hand power train, except the power lever 32, is pointing to the ground to reverse the power flow. The 2129~96 -appearance of this power lever 32 and its related components is seen in figure 6 and the details are in figure 8. The pivot point of power lever 32 is inserted in fulcrum shaft 26 at its midway length and is bolted down the centre of the cradle 24.
The bottom end of this power lever 32 has a chain (bicycle size) connected to the short lever of dual lever 34 (same construction of dual lever 35) where the bearing/bushing attaches and pivots to the other end of axle 36. The long lever of dual lever 34 has another piece of chain (bicycle size) running on sprocket 38 and wrap around at approximate 1/2 of its circumference. The chain after wrapping the sprocket, has extra links wherein the end is attached to an extension spring 42. Spring 42 is routed and aligned to the chain infeed and sprocket for the purpose of free binding operation. The end of spring 42 hooks to point 44, in line and opposite point 45 off side frame 3. The hub of clutch 40 is attached and keyed to shaft 37 and the right side of the big sprocket 46. Once again, the lock rotation of clutch 40 is within the rotation of the propelling wheel 1. When a chain is engaged to sprocket 38 and is pulled in the direction of the arrow marked on the platforms, clutch 38 will lock, turning shaft 36 (looking at a cross-section face) in a clockwise rotation, and transmits the power to the big sprocket 46. The big sprocket 41 transmits power to the small sprocket 47 by an endless chain 48 and thereon the propelling wheel 1 moves forward. The big sprocket 46 is four times larger than the 2l29l~5 driven small sprocket 44. Springs 42 and 43 reset the used chain into the standby relax mode by pulling the used chain on through the sprocket overrunninq their respective clutches which have just delivered power to shaft 37. The connection of power levers are from long to short. The flex-glass guard 50 encases the propellin~ wheel and appropriate moving parts to prevent injury to the rider. From these speed multiplier systems it is evident that a small arc movement at the fulcrums can generate wheel rotations, at a fair enough speed for the Rocking Board to be enjoyable.
It will be apparent to those skilled in this art that various modifications and changes are possible with the Rocking Board construction and the operatin~ system described herein without departin~ from the spirit and scope of the invention. Accordingly, all such modification and chan~es are intended to be part of this invention.

Claims (4)

1. A rocking board in rectangular shape, comprising of a substantially large propelling wheel positioned along the longitudinal centre of a four roller installation shape in rectangular format like a standard skateboard, held in position by an axle fastened to two side frames which hold further the two side power train and mechanism flexi-glass guard in conjunction, the bottom portion ends joined in unison to two outside parallel leverages to become a mechanism carrier lever having a front with inclined plain attached to two steerable rollers and the back straight portion ends attached to an axle for two performance rollers, after which a back inclined plain where brake pad are attached, aligned with these inclined plains are two platforms with an approximate equidistance to the propelling wheel peripheral diameter and rigidly held together by two see-saw leverages, which are parallel to mechanism carrier levers, each having a fulcrum shaft aligned, where the outside ends are supported and pivot to bearing posts located at the centre length of the mechanism carrier lever, with the inside ends carried and pivot to the side frames located below and vertically aligned to the propelling wheel axle.

2. The device of claim 1 wherein mechanism carrier levers have each end with inclined plain centrally located, the total length is longer than the see-saw lever and their material strength equal, the location of two back roller axles at the lever's straight portion is approximately 40% closer to the axle centre of the propelling wheel and the front two steerable rollers installed to the front inclined plain approximately 60% further to the propelling wheel axle centre, the installation of two steerable rollers in the incline plain will give the rolling surface off balance allowance to the back rollers' surfaces by 3/8 of an inch using the propelling wheel surface as a pivot point on a flat surface ground, meanwhile the installation of brake pad at the rear inclined plain makes manoeuvre braking effective.

3. The device of claim 1 wherein the back platform has a large back lead than the front one rigidly held together in a square by two see-saw levers where each lever has a separate aligned fulcrum shaft mounted and pivot below respective propelling wheel axle at the side frames which allow the platforms a low swing to the ground.

4. The device of claim 3 wherein the two separate see-saw levers produce two opposing power arcs at their fulcrum, are magnified at the two side power trains by leverages with equivalent travel length in the individual bicycle chain length wrapping around their sprockets wherein sprocket one way clutches convert the chain length strokes into a one way shaft rotation, a large sprocket to the shaft transmits the power by endless chain to the small sprocket coupled to the side of the propelling wheel and cause the rocking board movements.