INLINE SKATES HAVING STRAIGHT DRIVE TYPE JOINT

STRUCTURE

Technical Field

[1] The present invention relates to an inline skate having a joint frame structure enabling a straight skating method, in which biomechanical motion of a user when walking or running is applied to inline skating, thus minimizing kinetic energy loss, thereby enhancing the performance and efficiency thereof. Background Art

[2] Inline skates, which are recently gaining popularity as a leisure or exercise activity, include a pair of skate boots, which receive the user's feet therein, a plurality of wheels, which are mounted in a row to a frame that is provided under the lower surface of each skate boot along a longitudinal central line, and a brake pad, which is mounted to a rear end of the frame.

[3] Typically, in such an inline skate, because each skate boot is securely mounted to each frame, it is impossible for the user to skate using bending motion of his/her ankle and toes. Each wheel is rotatable both forwards and backwards without restriction. Therefore, as shown in FIG. 2, to propel the body forwards, the user must push his/her feet in directions oblique to a traveling direction. As such, in the conventional inline skate, the user travels using such propulsive force in a direction of resultant force of oblique skating motion. As a result, the efficiency of kinetic energy is reduced.

[4] Generally, to walk or run, one foot is supported on the ground, and the other foot moves in space and steps forwards while the center of gravity moves.

[5] At this time, as shown in FIG. 3, while the center of gravity moves forwards, the foot, which has been supported on the ground, is bent between a middle phalanx 106 and a distal phalanx 104 thereof, and the front part 105 of the foot comes into close contact with the ground. In this state, the user pushes the foot using muscles, which are disposed at front and rear positions of the ankle, thus propelling the body forwards. That is, the bending motion of the toes and the ankle is a prerequisite for obtaining propulsive force.

[6] If the user has a physical structure in which the toes and the ankle are not bent, the whole sole of the foot must remain on the ground while the other foot steps, or the user uses the tips of the toes in place of the front part 105 of the foot to propel his/her body forwards. In this case, motion is slow, and the ankle is overstrained to support the weight. Hence, the user skates in an unstable posture, and it is impossible to skate in a straight line. That is, the user skates in a zigzag pattern. This inconveniences and

quickly tires the user, thus markedly reducing the exercise performance.

[7] In the conventional inline skate, because the ankle and the toes are supported both by the skate boot having high stiffness and by the unbendable frame, the zigzag skating method is used, as shown in FlG. 1. However, the present invention improves on the conventional inline skate such that biomechanical motion of the user is applied to inline-skating, thus making it possible to skate in a straight line.

[8] Furthermore, the conventional inline-skating method is based on an ice-skating method. In the case of an ice skate, because resistance is relatively small, it is not difficult to skate even using small propulsive force. However, in the case of the inline skate, because the skate is typically used on a road paved with asphalt or another substance and is propelled by rolling motion of the wheels, damping force is relatively high, thus requiring greater propulsive force. Therefore, the user must use a relatively large amount of energy to obtain desired propulsive force. As well, when inline skating for a long time, there is the probability of safety hazards due to accumulated fatigue. Disclosure of Invention Technical Problem

[9] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an inline skate which allows a user to bend his/her ankle and toes such that the front part of the foot is used for forward propulsion in the same manner as when walking or running, thus reducing user's fatigue despite ensuring strong and rapid propulsive force.

Technical Solution

[10] In order to accomplish the above object, the present invention provides, including: a bendable soft skate boot having a receiving space therein; front and rear outsoles provided under the skate boot and rotatably coupled to each other by a hinge; front and rear frames respectively provided under lower surfaces of the front and rear outsoles so as to be rotatable with respect to each other around the hinge at a predetermined turning radius; and a wheel mounted to the front frame and prevented from being rotated backwards by a clutch bearing.

[11] The hinge may be constructed such that the front and rear outsoles have an upward rotating angular limit from 20° to 30° and a downward rotating angular limit of 0°. Furthermore, the hinge may comprise a plurality of hinges spaced apart from each other at regular intervals.

[12] The front and rear frames may be coupled to each other both by a guide slot, which has a predetermined curvature and is formed in a surface of one of the front and rear frames that face each other, and by a stop stud, which is inserted into the guide slot and

screwed at a predetermined position into the remaining frame.

[13] The inline skate may further include elliptical tubes, each having a predetermined curvature, provided on the front and rear frames at positions corresponding to each other; and a guide rod inserted in the elliptical tubes and supporting the front and rear frames, so that the front and rear frames are rotatable around the hinge.

[14] The wheel may include: a clutch bearing preventing the wheel from rotating backwards; and a stop key integrally fitted into notches, which are respectively formed in a circumferential inner surface of the wheel and a circumferential outer surface of the clutch bearing that correspond to each other.

[15] The skate boot may include: ankle hinges provided on the skate boot at opposite sides around an ankle of a user and supporting a bending motion of the ankle; a plurality of support ribs coupled to each of the hinge and the ankle hinges, the support ribs folding depending on rotation of the hinge and the ankle hinges; and fabric attached to adjacent support ribs and connecting the support ribs to each other. Brief Description of the Drawings

[16] FIGS. 1 and 2 are views comparing skating/accelerating characteristics of inline skates according to the conventional technique and the present invention;

[17] FlG. 3 is a conceptual view illustrating the state of the joint of the foot of a user when traveling or accelerating;

[18] FlG. 4 is a view showing an inline skate, according to a first embodiment of the present invention;

[19] FlG. 5 shows front and rear outsoles and an enlargement of hinges according to the present invention;

[20] FlG. 6 is a view showing a joint mechanism between front and rear frames according to the present invention;

[21] FlG. 7 is a schematic view showing another example of a joint mechanism between front and rear frames according to the present invention;

[22] FlG. 8 is a schematic view showing a further example of a joint mechanism between front and rear frames according to the present invention;

[23] FlG. 9 is a view showing a wheel shaft of FlG. 4;

[24] FlG. 10 is a sectional view showing a wheel according to the present invention;

[25] FlG. 11 is a side view showing a stop key provided in the wheel of FlG. 4;

[26] FIGS. 12 and 13 are a schematic view and an exploded perspective view, respectively, showing the front frame shown in FlG. 4;

[27] FlG. 14 is a view showing an inline skate, according to a second embodiment of the present invention;

[28] FlG. 15 is a view showing the inline skate of FlG. 14 when in a bent state;

[29] FlG. 16 is a detailed view showing a bending portion of a skate boot shown in FlG.

14; and

[30] FIGS. 17 through 21 are views showing several examples of a shaft locking mechanism applied to the inline skate of FlG. 14.

[31] <Description of the elements in the drawings>

[32] 1 : wheel 5: front frame 6: rear frame

[33] 7: guide slot 8: stop stud 9: front outsole

[34] 10: rear outsole 11: hinge 12: skate boot

[35] 13: ankle hinge 14: bendable part

Best Mode for Carrying Out the Invention

[36] The present invention relates to an inline skate, which includes frames, which are jointed to each other such that the skate is bendable, and a wheel, having a clutch bearing that prevents it from rotating backwards, so that, when a user skates or walks with the inline skate, smooth movement of the user's ankles and toes is ensured, thus reducing user's fatigue despite ensuring strong and rapid propulsive force.

[37] FIGS. 1 and 2 are views comparing skating/accelerating characteristics of inline skates according to a conventional technique and the present invention. As shown in the drawings, the inline skate of the present invention has a structure such that user's joints and muscles used when walking are applied to skating in a manner similar to walking. Therefore, the user can skate in a straight skating pattern 108 but does not skate in a zigzag skating pattern 107, as when using the conventional inline skate, so that power is efficiently transmitted, and the number of skating strokes is reduced to move the user a distance equal to that of the conventional art. This is realized by making the direction of application of propulsive force 101a equal to the traveling direction 102a.

[38] FlG. 3 is a conceptual view illustrating the state of the joint of the foot of the user when traveling or accelerating. FlG. 4 is a view showing an inline skate, according to a first embodiment of the present invention. As shown in the drawings, to propel the user's body forwards, the center of gravity of the body is moved towards the front part 105 of the foot and, simultaneously, the user pushes the ground in a straight direction while wheels 1 and 2, which are disposed just below the front part 105 of the foot, contact the ground. At this time, the other foot steps forwards such that force is evenly applied to the entire sole of the foot to disperse the weight of the user throughout all of the wheels 1, 2, 3 and 4, thus glidingly moving forwards. These motions are repeatedly conducted, so that the user wearing the inline skates advances forwards.

[39] FlG. 5 is a view showing a hinge installed in front and rear outsoles of the inline skate of the present invention. As shown in the drawing, the front and rear outsoles 9

and 10 support the skate boot 12, which is soft so as to ensure a bending motion thereof. The hinge 11 is provided at a junction between the front and rear outsoles 9 and 10, such that the outsoles are easily rotatable with respect to each other and are prevented from undesirably moving in a lateral direction.

[40] The hinge 11 has a structure similar to that of typical hinges, that is, has a structure in which a hinge shaft 1 Ia is surrounded by outsole plates, which interdigitate with each other. Preferably, grooves are formed in parts of the outsole plates which surround the hinge shaft, such that the outsole plates do not bend downwards more than a horizontal angle (180°) but bend upwards within a predetermined angular range (20° to 30°), thus preventing the foot and the inline skate from being forcibly bent when excessive load is applied backwards to the front part of the inline skate.

[41] Furthermore, a stop stud 8 is inserted into a guide slot 7, which is formed through a front frame 5, which will be explained later herein. Thus, when the inline skate is bent upwards, the stop stud 8 and the hinge 11 limit the angle at which the outsole is bent upwards to a range from 20° to 30° and prevent the outsole from being bent downwards more than a horizontal line (0°). As such, in the present invention, the front and rear outsoles 9 and 10 and the frame complement each other, thus ensuring the stability thereof.

[42] Here, the number of hinges 11 is not limited to one. That is, to ensure smooth bending operation, at least two additional hinges may be provided at positions spaced apart from the above-mentioned hinge 11 at regular intervals towards the front outsole 9 or the rear outsole 10, depending on the structure of the user's foot or the material of the skate boot 12.

[43] FIGS. 6 through 8 illustrate several examples of a joint mechanism between the front and rear frames according to the present invention.

[44] Referring to FIG. 6, an arc-shaped guide slot 7 is formed through the part of a front frame 5 that contacts a rear frame 6, such that the skate boot can be smoothly bent around the hinge 11. A stop stud 8, which is threaded on a circumferential outer surface of an end thereof, is inserted into the guide slot 7 and is tightened into a screw hole, which is formed in a part of the rear frame 6 which faces the front frame 5. Hence, the rear frame 6 is rotated with respect to the front frame 5 within a range defined depending on the radius of the arc-shaped guide slot 7. That is, the front and rear frames 5 and 6 are rotated with respect to each other while the stop stud 8 moves along the guide slot 7.

[45] In another example of a joint mechanism of the present invention, as shown in FIG.

7, a front frame 5 and a rear frame 6 are placed in the same plane. An elliptical tube 7a, which has a predetermined curvature and is divided into two parts, is provided throughout the front and rear frames 5 and 6. The two part of the elliptical tube 7a,

which face each other, are provided on the respective front and rear frames 5 and 6. Furthermore, an elliptical guide rod 8b, having a single body and a curvature corresponding to the elliptical tube 7a, is placed in the elliptical tube 7a. Thus, when the front and rear frames 5 and 6 are rotated with respect to each other, the two divided parts of the elliptical tube 7a reciprocate with respect to each other and are supported by the elliptical guide rod 8b. At this time, the hinge 11 serves as a hinge point. Therefore, it is preferable that the guide rod 8b and the tube 7a have curvatures corresponding to a circle, the center of which is the hinge 11, and the radius of which is the distance between the hinge 11 and tube 7a.

[46] FIG. 8 is a schematic view showing a further embodiment of the joint mechanism between front and rear frames 5 and 6 according to the present invention. In a manner similar to the embodiment of FIG. 6, guide grooves 7, which correspond to each other, are formed in respective surfaces of the front and rear frames 5 and 6, which face each other. A ball bearing 8a is interposed between the guide grooves 7, so that the ball bearing 8a moves along the guide grooves 7 around the hinge 11 while bending operation of the inline skate is conducted. Meanwhile, a wheel 1 has a backward rotation prevention device, in which a clutch bearing 204 serving to prevent it from rotating backwards is installed, such that, when the user steps to propel forwards, the wheel 1 is securely supported on the ground using frictional force. The clutch bearing is realized using well known technology, therefore further explanation is deemed unnecessary.

[47] As shown in FIG. 10, the wheel 1 includes the clutch bearing 204, a typical bearing

205, a bearing housing 206 and an outer bearing 207 which are provided around a wheel shaft 203. The bearing 205 serves to sustain a load applied to the wheel, and the outer bearing 207 serves to transmit a load, applied to the wheel shaft, to the frame and is a structure which is not provided in the conventional inline skate.

[48] In the case of a bearing provided in the wheel of the conventional inline skate, because friction is small on a rolling portion, a slipping phenomenon induced on the wheel shaft or wheel is negligible. However, in the inline skate of the present invention, when a load is abruptly applied to the wheel shaft in a backward direction, energy loss due to a slipping phenomenon may be induced.

[49] FIG. 11 is a side view showing a stop key provided in the wheel of FIG. 4. As described above, to prevent energy loss and to ensure reliable power transmission, insertion notches are respectively formed in the circumferential inner surface of a wheel 208 and in the circumferential outer surface of the clutch bearing 204 at positions corresponding to each other. A stop key 27 is fitted into the insertion notches, so that the wheel is integrated with the clutch bearing 204, thus preventing energy loss due to slippage. Here, the means for locking the clutch bearing to the wheel is not

limited to the stop key 27. In other words, it must be appreciated that locking members, such as a pin and a screw, are also included within the technical bounds of the present invention.

[50] Furthermore, as shown in FIG. 9, the wheel shaft 203, which supports the wheel 1 according to the first embodiment of the present invention, includes a rectangular head part 203a and a rectangular distal end part 203b in order to prevent the wheel shaft 203 from rotating. Rectangular holes, corresponding to the head and distal end parts of the wheel shaft 203, are formed in the frame, to which the wheel shaft 203 is mounted. Thus, the wheel shaft 203 is inserted into the rectangular holes in a direction from the larger hole to the smaller hole.

[51] As well, a locking screw is tightened into the distal end part of the wheel shaft 203 such that the head part 203a and the distal end part 203b, which are inserted into the rectangular holes of the frame, are prevented from undesirably rotating. In addition, a stopper 203c is provided on the head part to prevent the wheel shaft from being completely inserted into the frame. As such, the wheel shaft 203 is securely fastened to the frame both using the locking screw, which is screwed into a threaded hole formed in the distal end part 203, and using the stopper 203c, which contacts the frame. In this embodiment, the head part 203a and the distal end part 203b are described as having rectangular shapes, but, because other polygonal shapes, such as hexagonal and octagonal shapes, can provide the same function as that of the rectangular shape, it must be understood that these also fall within the technical bounds of the present invention.

[52] Thanks to the above-mentioned structure, energy concentrated on the front part 105 of the foot of the user is efficiently transmitted to the ground through the wheel 1 so that the inline skate can advance in the same direction as the rolling direction of the wheel, and the wheel can rotate forwards without restriction but is prevented from rotating backwards.

[53] FIGS. 12 and 13 are, respectively, a schematic view and an exploded perspective view showing the front frame according to the first embodiment of the present invention.

[54] As shown in the drawings, the wheel 1 is mounted to an end frame 30 having a wheel height adjusting structure. Thus, it is constructed such that the wheel 1 is spaced apart from the ground while traveling, thus improving the traveling performance. This structure may not be used in the case that rolling resistance of the clutch bearing 204 is very low due to high accuracy, unlike the typical bearing. Furthermore, even though the wheel is reduced in diameter in place of using the wheel height adjustment device so that the wheel is spaced apart from the ground by a distance of 5mm or less, the same effect is obtained.

[55] The end frame 30 is provided on the end of the front frame 5. In detail, the end frame 30 is rotatably coupled at a predetermined position to a support hinge 31, which is provided at a predetermined position on the front frame 5. A plurality of height adjustment holes 32 and 33 is formed at another predetermined position through the end frame 30, such that the height of the wheel is adjustable.

[56] Furthermore, a locking hole is also formed in the front frame 5 at a position corresponding to the height adjustment holes 32 and 33, so as to adjust the orientation of the end frame 30. To adjust the height of the wheel, a selected one of the height adjustment holes 32 and 33 is aligned with the locking hole formed in the front frame 30. Thereafter, a locking pin 34 is tightened into the aligned holes. The height of the wheel is selectively adjusted using this method. In this embodiment, in the case that the height adjustment hole 32 is aligned with the locking hole, the height of the wheel 1 mounted to the end frame 30 is adjusted to a lower position, and, in the case that the height adjustment hole 33 is aligned with the locking hole, the height of the wheel 1 is increased.

[57] In other words, in the case that the locking pin 34 is tightened into the height adjustment hole 33, the wheel 1 is disposed at the same height as that of the other wheels 2, 3 and 4. In the case that the locking pin 34 is tightened into the height adjustment hole 32, the wheel 1 is disposed at a position spaced apart from the ground by a predetermined distance. The technical principle of this structure is equal to that of the case in which the hinge, which is the rotating center, is disposed at a lower position and the height adjustment holes are disposed at an upper position.

[58] FIGS. 14 and 15 are views showing an inline skate, according to a second embodiment of the present invention.

[59] In the second embodiment of the present invention, a joint mechanism between front and rear frames 5 and 6 and front and rear outsoles 9 and 10 have the same construction as those of the first embodiment, and the same reference numerals and names are used, therefore further explanation will be omitted.

[60] The second embodiment of the present invention further includes ankle hinges 13, which are provided on a skate boot 12 at opposite sides around the ankle of the user, as well as including a hinge 11 of the outsole of the skate boot 12. Furthermore, a bendable part 14, which has flexible fabric 15 and support ribs 16, is provided on each of bending parts of the skate boot, at which the skate boot bends around the hinge 11 and the ankle hinges 13. The wheel 1 is provided on a wheel shaft, the end of which has a semicircular cross-section, and which is selectively locked by a locking means, so that the wheel 1 is selectively rotatable backwards.

[61] Hereinafter, the second embodiment of the present invention will be explained in detail with reference to the attached drawings.

[62] As shown in FIGS. 14 and 15, the ankle hinges 13 are provided on the skate boot 12 around the ankle of the user. The bendable parts 14, each of which consists of the flexible fabric 15 and the support ribs 16, are formed in the skate boot 12, such that the skate boot 12 is smoothly bent around the hinge 11 and the ankle hinges 13. Furthermore, the second embodiment has a structure such that backward rotation of the wheel 1 is controlled by a means for selectively locking the wheel shaft 203.

[63] As shown in FlG. 16, each bendable part 14, which is bent around the hinge 11 or the ankle hinge 13, includes the flexible fabric 15 and the support ribs 16. The support ribs 16 serve to sustain a load and support the flexible fabric 15 while it is wrinkled when the skate boot is bent. Therefore, when the skate boot 12 is bent, the skate boot keeps the foot of the user comfortable, thus making it possible for the user to skate more smoothly and comfortably.

[64] The several support ribs 16 are coupled to the hinge 11 and the ankle hinges 13, and the flexible fabric 15 is provided between adjacent support ribs 16. Thus, when the skate boot is bent around the hinge 11 and the ankle hinges 13, the bendable parts 14, each of which includes the support ribs 16 and the flexible fabric 15, are wrinkled. As such, when the user skates or walks, the bending motion of the skate boot is repeatedly conducted, as shown in FIGS. 14 and 15.

[65] FIGS. 17 through 21 are views showing several examples of a shaft locking mechanism for selectively controlling the backward rotation of the wheel shaft, according to the second embodiment of the present invention. These examples will be explained in detail herein below.

[66] The wheel 1 having the clutch bearing 204 is constructed such that reverse rotation of the wheel 1 is controlled by locking the wheel shaft 203. That is, the method of operating the wheel 1 is changed by locking or releasing the wheel shaft 203.

[67] FlG. 17 is a view of a critical part of another example of a wheel shaft locking mechanism of the wheel 1 having the clutch bearing when viewing a side view of the inline skate. As shown in the drawing, an end of the wheel shaft 203 has a semicircular cross-section. Support rings 18 are integrally provided on the frame at regular intervals.

[68] Furthermore, a locking key 17 having a predetermined length is inserted into the support rings 18 and selectively contacts a planar surface of the semicircular cross- sectioned end of the wheel shaft 203 to lock the wheel shaft 203.

[69] Here, the locking key 17 and the support rings 18 are preferably arranged in the longitudinal direction of the frame.

[70] In the case of this construction, when the user moves the locking key 17 towards the wheel shaft 203, the locking key 17 is brought into contact with the planar surface of the semicircular cross-sectioned end of the wheel shaft 203, thus locking the wheel

shaft 203.

[71] Conversely, when the locking key 17 has moved in a direction away from the wheel shaft 203, the locking key 17 does not interfere with the wheel shaft 203, that is, the wheel shaft 203 is released.

[72] FlG. 18 is a view of a critical part of a further example of the wheel shaft locking mechanism of the wheel 1 having the clutch bearing when viewing a side view of the inline skate. Here, the drawing disposed at an upper position illustrates the locked state of the wheel shaft, and the drawing disposed at a lower position illustrates the unlocked state of the wheel shaft. As shown in the drawings, one end of the wheel shaft 203 has a semicircular cross-sectioned shape, in the same manner as that of the former example. A rectangular locking plate is eccentrically provided at a predetermined position on the front frame 5 using a screw.

[73] In this case, as shown in FlG. 18, when the locking plate is oriented such that a surface thereof contacts the planar surface of the semicircular cross-sectioned end of the wheel shaft 203, it serves as a normal locking plate 19, thus locking the wheel shaft 203. When the locking plate is oriented in the opposite direction, that is, in the direction moving away from the planar surface of the semicircular cross-sectioned end of the wheel shaft 203, it serves as the turned locking plate 20, thus releasing the wheel shaft 203.

[74] FIGS. 19 through 20 are views of a critical part of a further example of the wheel shaft locking mechanism when viewing a plan view of the inline skate. In this case, one end of the wheel shaft 203 has a semicircular cross-sectioned shape in the same manner as in the previous examples.

[75] Furthermore, an elastic locking key 21, having a predetermined length, is hinged to a support piece 23, which is provided on the frame 5 at a position adjacent to the wheel shaft 203. The elastic locking key 21 is coupled at an end thereof to the support piece 23 through a spring 22, such that an eccentric elastic force is applied to the elastic locking key 21.

[76] In this construction, the elastic locking key 21 is rotated around the support piece

23, thus selectively locking or unlocking the wheel shaft 203.

[77] In detail, as shown in FlG. 19, when the elastic locking key 21 is rotated towards the wheel shaft 203, an end of the elastic locking key 21 is brought into contact with the planar surface of the semicircular cross-sectioned end of the wheel shaft 203, thus locking the wheel shaft 203. Conversely, as shown in FlG. 20, when? the elastic locking key 21 is rotated in a direction away from the wheel shaft 203, the end of the elastic locking key 21 is removed from the planar surface of the semicircular cross- sectioned end of the wheel shaft 203, thus releasing the wheel shaft.

[78] FlG. 21 is a view of a critical part of yet another example of the wheel shaft locking

mechanism when viewing a side view of the inline skate. In this case, a ring-shaped knob 26 is coaxially and rotatably provided around an end of the wheel shaft 203. A pushing member 24, which is tapered such that it is inclined in one direction, is provided on the circumferential inner surface of the ring-shape knob 26.

[79] Furthermore, a compression member 25, one end of which is hinged, is provided between the wheel shaft 203 and the pushing member 24 of the ring-shaped knob 26.

[80] In the case of this construction, when the user rotates the ring-shaped knob 26 in one direction at a predetermined angle, the pushing member 24, having a tapered shape, pushes the outer surface of the compression member 25 due to the shape thereof. Then, an end of the compression member 25 is rotated around the hinge and is brought into close contact with the circumferential outer surface of the wheel shaft 203, thus locking the wheel shaft 203. Conversely, when the user rotates the ring- shaped knob 26 in the opposite direction, the compression force of the pushing member 24, which has been applied to the compression member 25, is removed, so that the wheel shaft is released. Industrial Applicability

[81] As described above, in the present invention, biomechanical motion is applied to inline skating, so that a straight skating method is possible. Such a new skating method has an advantage of high efficiency compared to the conventional inline skate.

[82] Particularly, when traveling a relatively long distance or skating at high speed, the present invention reduces physical fatigue and thus makes it possible for the user to skate faster. Furthermore, in the case that a locking mechanism of a clutch wheel is released, the user can skate in the same skating manner as in the conventional art. Moreover, the present invention permits bending motion of the ankle and toes of the user when skating, thus making it possible for the user to skate more efficiently.

[83] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.