US2865645A - Roller skate having continuously applied braking means - Google Patents
Roller skate having continuously applied braking means Download PDFInfo
- Publication number
- US2865645A US2865645A US672988A US67298857A US2865645A US 2865645 A US2865645 A US 2865645A US 672988 A US672988 A US 672988A US 67298857 A US67298857 A US 67298857A US 2865645 A US2865645 A US 2865645A
- Authority
- US
- United States
- Prior art keywords
- shaft
- raceway
- axle
- skate
- roller skate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63C—SKATES; SKIS; ROLLER SKATES; DESIGN OR LAYOUT OF COURTS, RINKS OR THE LIKE
- A63C17/00—Roller skates; Skate-boards
- A63C17/14—Roller skates; Skate-boards with brakes, e.g. toe stoppers, freewheel roller clutches
Definitions
- Fig. .1 illustrates 'aportion of a skate showing a side view of a wheel and the partiallypreventing means.
- Fig. 2 is an enlarged fragment .of thelnreans for controlling said partially preventing means.
- Fig. 3 also shows a front view of a part shown in Fig. 4 illustrates the inventionappliedto other portions of a skateshowin als in s ctio a whe hrpert a ly preventing means applied thereto and the controller of said means.
- Fig. 4a shows the construction of the axle of the partial preventer.
- Fig. 4b and Fig. 40 show the meansfor controlling the partial preventer.
- Fig. 5 shows a modification of Fig. 4.
- FIG. 1 there is shown a platform for attaching the skate to the foot of the user, a frame 26 attached to the platform 15, a pair of wheels (only one is shown) mounted onthe frame 26 by means of axle 27 and a flange which is a part of the lever 16.
- flange 25 is not shown in contact with wheel 20.
- Figure 3 may be seen another view of the lever 16 and the flange 25.
- One end of the lever .16 is attached to the frame 26 at a point 31 in a manner which permits the lever 16 to have freedom of movement or the lever 16 may be constructed so as to be somewhat flexible
- This application is a division-off 2,865,645 Patented Dec. 23, 1958 ice "and fastened firmly to the point '31.
- the other endof thelever 16 fits over ;a threaded shaft 18, said sl 1aft.18 being fastened to the platform 15.
- the-plate "17 is shown-to have a hole 24'which hasa flaton one side and 'is without threads and by which means the plate '17-fits over the shaft 18 being permitted to move along the shaft '18 but not to turn.
- Figure 2b shows an end .view of the ,nut 19 and Figure 2c shows a flat side '23 o-n'the shaft 18 whose-diameter is such as to'permit the flat sided hole 24 in plate 17 to readily fit over. the shaft 18 and engage the flatside 23 as described above.
- the-nut 1-9 has on the periphery thereof a graduated scale "22.
- Theplate -17 has on its periphery a marker Zr-and 'since the plate 17 does not rotate relative to the shaft 18, the marker 21 serves 'as a point ofreference.
- the nut19 is turned so as to move toward the'plate 17 pressure is applied to the'lever "16'by'the spring 30a and the spring 'Stlthuscausing the flange 25 to engage the wheels"20.
- the invention may be practiced without the spring 30a and the spring 30 it has been foundthat one-spring alone or both will'prevent seizing of the flange 25 to the wheels 20.
- the partially restricting means may be applied to any one -or more of the wheels of a skateas has been shown in Figure 1 and as will be described hereinafter in Figure 4, or in a combination of 'the'arrangernents of Figure l and ure 4 or the like.
- FIG. '4 there is shown in section a wheel 40, the ball'bearin'gs '42 and a shaft'41 having a flared raceway 43 in-which the ball bearings "42 support the-wheel-4t in conjunction with the fixed raceway '44.
- the shaft 41 passes through the "fixed raceway 44 which is part of the frame 39.
- the shaft 41 has, on its en'dwhic'h isopposite the Fflared raceway 43, a slot 50 and an external thread i54.
- the slot 50 is engaged by atongu e part 49 fof the-shaft '53 which has an externaPthread 48 *oppos'itie' in" direction compared with the thread 54.
- the 'shaft'53 passes' through another fixed raceway '44 (partly shown) which is part of the frame 39.
- the shaft' 53 * has on its'end opposite t-he tongue 49 another flared racewayfl (not'shown) "which with ball bearings 42 has mounted thereon another wheel 40.
- the shaft 53 and the shaft 41 are able to move in and out of the fixed raceways 44 and may or may not turn freely.
- An adjusting nut 45 engages the shaft 41 and the shaft 53 by internal threads which mate with the thread 54 and the thread 48.
- the nut 46 serves to lock the adjusting nut 45 by being screwed tightly against it.
- the collar 47 is fastened to the shaft 41 and has engraved thereon a mark 52 which serves as a reference point.
- a scale 51 which may be graduated in inches or centimeters and fractions thereof or the like.
- axle support 57 is joined to the support 58 by means of a shaft 63.
- the axle 61 has a thread 2&3
- a flared portion 64 serving as a raceway on its opposite end and the threaded end having a flat portion23 as shown in Figure2c.
- the nut 19, the scale 22, and the collar 17 have been shown in Figure 2b and Figure 2a respectively as has the spring in Figure 5.
- Thespring 30, is applied to a raceway 62, said raceway 62 being able to ride freely on the shaft 61.
- the raceway 64 is drawn toward the raceway 62 thus applying a force through the ball bearings 42 to the wheels 40 thereby inhibitingthe motion of the wheels 40.
- the user may attach the skate to the foot in any well known manner.
- a more proficient skater using a skate constructed with a rear assembly in accordance with Figure 1 and a front assembly in accordance with Figure 4 will find that two different adjustments of the movement of the skate are possible.
- trick maneuvers may be performed by the manipulation of the riders weight toward one set of the wheels ,or toward the other set.
- a roller skate which comprises a support connected with a footplate, rotary means for providing motion to said skate, said rotary means comprising two wheels mounted on opposite sides of said support by means. of an axle, said axle passing freely through two raceways afiixed respectively on said opposite 4 sides of said support, said axle comprising a first portion having a raceway on one end and a second portion having a raceway on one end, a variable force producing means adapted to join the end opposite said raceway of said first portion of said axle with the end opposite said raceway of said second portion of said axle and ball bearings engaging said respective raceways and said Wheels.
- variable force producing means comprises a nut in threaded relation with said first portion and said second portion of said axle, means for locking said nut and means for gauging theforce applied by said nut.
- a roller skate which comprises a support connected with a footplate, rotary means for providing motion to said'skate, said rotary means comprising two wheels mounted, on opposite sides of said support by means of an axle, said axle passing freely through two raceways afiixed respectively on said opposite sides of said support,:said axle having a first raceway on one end, ball bearings engaging said first raceway and a side of one wheel, ball bearings engaging the other side ofsaid wheel and one of said afiixed raceways, a second raceway freely mounted on said axle, ball bearings engaging said freely mounted raceway and one side of the other wheel, ball bearings engaging the other side of said other wheel and the other of said afiixed raceways, the portion of said axle opposite its first raceway adapted for mounting a nut in threaded relation thereto, a helical spring engaging said nut and said freely mounted raceway, means for locking said nut in a predetermined position and means for gauging the force applied by said a rot
- a roller skate the combination which comprises a support connected .witha footplate, rotary means for providing motion to said skate, said rotary means mounted on opposite sides of said support by means of an axle, said axle adapted for free movement in a direction transverse to the rotation of said rotary means, self-adjustable force transmitting means for coupling said axle to said rotary means and means for applying a controllable force to said axle whereby said self-adjustable force transmitting means constrains said rotary means at all times.
- said axle' is adapted to include free rotation in a direction parallel to the rotationof said rotary means.
- the combination as claimed in claim 5 including means adapted for gauging the force of said means for applying a controllable force.
Landscapes
- Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)
- Motorcycle And Bicycle Frame (AREA)
Description
Dec. 23, 1958 s, LEVIN 2,865,645
ROLLER SKATE HAVING CONTINUOUSLY APPLIED BRAKING MEANS Original Filed May 16, 1955 2 Sheets-Sheet 1 .1 .5. 159+. T =1 Af g;
47 INVENTOR Dec. 23, 1958 s. LEVIN 2,865,645
ROLLER SKATE HAVING CQNTINUOUSLY APPLIED BRAKING MEANS Original Filed May 16, 1955 2 Sheets-Sheet 2 NVENTQR nited tates ROLLER SKATE HAVHNG CONTINUOUSLY APPLIED BRAKING MEANS The invention relatesgenerallyto skates utilizing rotary means to providemotionand more specifically to skates that maybe utilized, for example, for initiating beginners in the art of skating or-for training purposes, although not limited thereto. and is co-pending withmy application Serial No. 508,475 filed May '16, 1955.
If a novice in the art ofskatingis carefully observed itwill be seen that the usual freedom of motion of a skate prevents a maintenance .of balance as the skate has a tendency to move more quickly-thanthe rider. The obvious resultais frequent falls, possible injury and usually discouragement. Until the'ankles are strengthened and a sense of balance is developed the'conventional skate remains a hazard,*particularly for the young.
It is an object .of the invention to provide a skate whereby the art of skating maybe quickly and safely assimilated.
It is another objectof the invention toprovide a training skate which is simple indesign and economical to construct.
It is an objectof the t-invention to provide a roller skate having means for partially preventing rotation of the skate wheels.
With the above objects inview, together with such other objects and advantages .as may subsequently appear, the invention resides in parts hereinafter described by way .of example, :in the following specification of certain modes of execution of the invention and illustrated in .the accompanying drawings in which:
Fig. .1 illustrates 'aportion of a skate showing a side view of a wheel and the partiallypreventing means.
Fig. 2 is an enlarged fragment .of thelnreans for controlling said partially preventing means.
2a. g-12b andfig. Zc-s n-deta se r l of the parts shown in Fig. 2.
Fig. 3 also shows a front view of a part shown in Fig. 4 illustrates the inventionappliedto other portions of a skateshowin als in s ctio a whe hrpert a ly preventing means applied thereto and the controller of said means.
Fig. 4a shows the construction of the axle of the partial preventer.
Fig. 4b and Fig. 40 show the meansfor controlling the partial preventer.
Fig. 5 shows a modification of Fig. 4.
Referring to Figure 1 there is shown a platform for attaching the skate to the foot of the user, a frame 26 attached to the platform 15, a pair of wheels (only one is shown) mounted onthe frame 26 by means of axle 27 and a flange which is a part of the lever 16. For clarity flange 25 is not shown in contact with wheel 20. In Figure 3 may be seen another view of the lever 16 and the flange 25. One end of the lever .16 is attached to the frame 26 at a point 31 in a manner which permits the lever 16 to have freedom of movement or the lever 16 may be constructed so as to be somewhat flexible This application is a division-off 2,865,645 Patented Dec. 23, 1958 ice "and fastened firmly to the point '31. The other endof thelever 16 fits over ;a threaded shaft 18, said sl 1aft.18 being fastened to the platform 15. 1
Referring now to Figure 2, which is an enlarged portion of Figure 1, it will be seen that thelever 16 'fits over the shaft 18f-by means of a hole 28 which is sufficiently large in diameterto permit movement of the lever 16 along the shaft 18. constraining the lever 16 are the spring 30a and the spring '30. The spring 30 is utilized between the lever 16 and the platform 15 and the spring 300 is utilized between the lever 16 "and a plate'17. The plate '17 rides upon an internally threaded nut 19 which may be raised or lowered on the thread 29 on the shaft '18. Referring to Figure 2a, the-plate "17 is shown-to have a hole 24'which hasa flaton one side and 'is without threads and by which means the plate '17-fits over the shaft 18 being permitted to move along the shaft '18 but not to turn. "Figure 2b shows an end .view of the ,nut 19 and Figure 2c shows a flat side '23 o-n'the shaft 18 whose-diameter is such as to'permit the flat sided hole 24 in plate 17 to readily fit over. the shaft 18 and engage the flatside 23 as described above. Referring again to Figure12, the-nut 1-9 has on the periphery thereof a graduated scale "22. Theplate -17 has on its periphery a marker Zr-and 'since the plate 17 does not rotate relative to the shaft 18, the marker 21 serves 'as a point ofreference. When the nut19 is turned so as to move toward the'plate 17 pressure is applied to the'lever "16'by'the spring 30a and the spring 'Stlthuscausing the flange 25 to engage the wheels"20. Althoughthe invention may be practiced without the spring 30a and the spring 30 it has been foundthat one-spring alone or both will'prevent seizing of the flange 25 to the wheels 20.
- In accordance-with the' -in vention, the partially restricting means may be applied to any one -or more of the wheels of a skateas has been shown in Figure 1 and as will be described hereinafter in Figure 4, or in a combination of 'the'arrangernents of Figure l and ure 4 or the like. J
Referring now to Figure '4 there is shown in section a wheel 40, the ball'bearin'gs '42 and a shaft'41 having a flared raceway 43 in-which the ball bearings "42 support the-wheel-4t in conjunction with the fixed raceway '44. The shaft 41 passes through the "fixed raceway 44 which is part of the frame 39. V
in Figure 4a, and Figure 477 *it can be seen that "the shaft 41 has, on its en'dwhic'h isopposite the Fflared raceway 43, a slot 50 and an external thread i54. The slot 50 is engaged by atongu e part 49 fof the-shaft '53 which has an externaPthread 48 *oppos'itie' in" direction compared with the thread 54. The 'shaft'53passes' through another fixed raceway '44 (partly shown) which is part of the frame 39. The shaft' 53 *has on its'end opposite t-he tongue 49 another flared racewayfl (not'shown) "which with ball bearings 42 has mounted thereon another wheel 40. The shaft 53 and the shaft 41 are able to move in and out of the fixed raceways 44 and may or may not turn freely.
An adjusting nut 45 engages the shaft 41 and the shaft 53 by internal threads which mate with the thread 54 and the thread 48. The nut 46 serves to lock the adjusting nut 45 by being screwed tightly against it. When the adjusting nut 45 is turned the tongue 49 slides in the slot 50 permitting an increase or decrease in the separation of the shaft 41 and the shaft 53 at the same time preventing rotation with respect to each other. The collar 47 is fastened to the shaft 41 and has engraved thereon a mark 52 which serves as a reference point.
On the adjusting nut 45 is engraved a scale 51 which may be graduated in inches or centimeters and fractions thereof or the like.
- By bringing the said shafts 41 and 48 together, pressure is applied-through the ball bearings 42 to the wheels 40. The 'rotati'onof the wheels 40 is thus prevented to a degree which may be predetermined by setting the adjusting nut 45 in accordance with the graduated scale 51.
Referring to Figure there is shown a modification of Figure 4 in which. the-principle of the invention is fur- .ther set forth. The wheels 40, the ballbearings 42, the
fixed raceways 44, "the axle support 57 and the upper support 58 attached to footplate have been previously described. .The axle support 57 is joined to the support 58 by means of a shaft 63. The axle 61 has a thread 2&3
on one end, a flared portion 64 serving as a raceway on its opposite end and the threaded end having a flat portion23 as shown in Figure2c. The nut 19, the scale 22, and the collar 17 have been shown in Figure 2b and Figure 2a respectively as has the spring in Figure 5. Thespring 30,is applied to a raceway 62, said raceway 62 being able to ride freely on the shaft 61. When the spring 30 is compressed by turning the nut 19 the raceway 62 presses against the ball bearings 42 in contact with it. At the same time the raceway 64 is drawn toward the raceway 62 thus applying a force through the ball bearings 42 to the wheels 40 thereby inhibitingthe motion of the wheels 40. The user may attach the skate to the foot in any well known manner.
At first enough pressure is applied to rather heavily restrict the motion of the wheels and skating is practiced. The skater will find that it is very'easyto stand up and balance is quickly learned. As training progresses the pressure is gradually released in definite steps in accordance with the scale 51 or thescale 22 whichever is used, the actual quantities being dependent on such factors as the age, previous skill, weight and the like of the user whoquickly becomes an accomplished performer.
A more proficient skater, using a skate constructed with a rear assembly in accordance with Figure 1 and a front assembly in accordance with Figure 4 will find that two different adjustments of the movement of the skate are possible. By this means trick maneuvers may be performed by the manipulation of the riders weight toward one set of the wheels ,or toward the other set.
It can also be seen that the young will find great safety in the invention in addition to the pleasures thereof.
It is to be understood that various equivalents of the embodiment disclosed may beused without departing from the spirit and scope of the invention.
What is claimed is:
1. In a roller skate the combination which comprises a support connected with a footplate, rotary means for providing motion to said skate, said rotary means comprising two wheels mounted on opposite sides of said support by means. of an axle, said axle passing freely through two raceways afiixed respectively on said opposite 4 sides of said support, said axle comprising a first portion having a raceway on one end and a second portion having a raceway on one end, a variable force producing means adapted to join the end opposite said raceway of said first portion of said axle with the end opposite said raceway of said second portion of said axle and ball bearings engaging said respective raceways and said Wheels.
2. In a roller skate the combination as claimed in claim 1 including means adapted for gauging the force of said force producing means.
3. In a roller skate the combination as claimed in claim 1 wherein said variable force producing means comprises a nut in threaded relation with said first portion and said second portion of said axle, means for locking said nut and means for gauging theforce applied by said nut.
4. In a roller skate the combination which comprises a support connected with a footplate, rotary means for providing motion to said'skate, said rotary means comprising two wheels mounted, on opposite sides of said support by means of an axle, said axle passing freely through two raceways afiixed respectively on said opposite sides of said support,:said axle having a first raceway on one end, ball bearings engaging said first raceway and a side of one wheel, ball bearings engaging the other side ofsaid wheel and one of said afiixed raceways, a second raceway freely mounted on said axle, ball bearings engaging said freely mounted raceway and one side of the other wheel, ball bearings engaging the other side of said other wheel and the other of said afiixed raceways, the portion of said axle opposite its first raceway adapted for mounting a nut in threaded relation thereto, a helical spring engaging said nut and said freely mounted raceway, means for locking said nut in a predetermined position and means for gauging the force applied by said nut.
5. In a roller skate, the combination which comprises a support connected .witha footplate, rotary means for providing motion to said skate, said rotary means mounted on opposite sides of said support by means of an axle, said axle adapted for free movement in a direction transverse to the rotation of said rotary means, self-adjustable force transmitting means for coupling said axle to said rotary means and means for applying a controllable force to said axle whereby said self-adjustable force transmitting means constrains said rotary means at all times. 6. In a roller skate, the combination as claimed in claim 5 wherein said axle' is adapted to include free rotation in a direction parallel to the rotationof said rotary means.
7. In a roller skate, the combination as claimed in claim 5 including means adapted for gauging the force of said means for applying a controllable force.
References Cited in the file of this patent UNITED STATES [PATENTS 822,782 Hruby Mar. 24, 1908 2,160,432 Davidson May 30, 1939 2,725,238 Day Nov. 29, 1955
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US672988A US2865645A (en) | 1955-05-16 | 1957-07-19 | Roller skate having continuously applied braking means |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US508475A US2865644A (en) | 1955-05-16 | 1955-05-16 | Controllable skate having continuously applied brake |
US672988A US2865645A (en) | 1955-05-16 | 1957-07-19 | Roller skate having continuously applied braking means |
Publications (1)
Publication Number | Publication Date |
---|---|
US2865645A true US2865645A (en) | 1958-12-23 |
Family
ID=27056204
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US672988A Expired - Lifetime US2865645A (en) | 1955-05-16 | 1957-07-19 | Roller skate having continuously applied braking means |
Country Status (1)
Country | Link |
---|---|
US (1) | US2865645A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4127282A (en) * | 1977-02-23 | 1978-11-28 | Hans Gorlach | Skate board vehicle |
US5232231A (en) * | 1992-08-12 | 1993-08-03 | Bruce Carlsmith | Brake for roller skates |
US5511805A (en) * | 1994-05-12 | 1996-04-30 | Mcgrath; Neal | Braking apparatus for use with in-line roller skates |
US5947486A (en) * | 1994-11-04 | 1999-09-07 | City Glider Product Gmbh | Biodynamic roller skate |
US20030214104A1 (en) * | 2002-05-17 | 2003-11-20 | Chuck Chang | Roller skate having a safety device |
US20100314851A1 (en) * | 2009-06-10 | 2010-12-16 | James Stewart Palmer | Speed control system |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US822782A (en) * | 1904-05-23 | 1906-06-05 | Clarence L Altemus | Current-distributer for sparking devices. |
US2160432A (en) * | 1938-06-28 | 1939-05-30 | George P Buzan | Dipper door control |
US2725238A (en) * | 1952-01-29 | 1955-11-29 | Samuel S Day | Training-type roller skate |
-
1957
- 1957-07-19 US US672988A patent/US2865645A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US822782A (en) * | 1904-05-23 | 1906-06-05 | Clarence L Altemus | Current-distributer for sparking devices. |
US2160432A (en) * | 1938-06-28 | 1939-05-30 | George P Buzan | Dipper door control |
US2725238A (en) * | 1952-01-29 | 1955-11-29 | Samuel S Day | Training-type roller skate |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4127282A (en) * | 1977-02-23 | 1978-11-28 | Hans Gorlach | Skate board vehicle |
US5232231A (en) * | 1992-08-12 | 1993-08-03 | Bruce Carlsmith | Brake for roller skates |
US5511805A (en) * | 1994-05-12 | 1996-04-30 | Mcgrath; Neal | Braking apparatus for use with in-line roller skates |
US5947486A (en) * | 1994-11-04 | 1999-09-07 | City Glider Product Gmbh | Biodynamic roller skate |
US20030214104A1 (en) * | 2002-05-17 | 2003-11-20 | Chuck Chang | Roller skate having a safety device |
US20100314851A1 (en) * | 2009-06-10 | 2010-12-16 | James Stewart Palmer | Speed control system |
US8371594B2 (en) * | 2009-06-10 | 2013-02-12 | James Stewart Palmer | Speed control system |
US20130118843A1 (en) * | 2009-06-10 | 2013-05-16 | James Stewart Palmer | Speed control system |
US8500136B2 (en) * | 2009-06-10 | 2013-08-06 | James Stewart Palmer | Speed control system |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4738456A (en) | Wheeled ski simulator | |
US4084831A (en) | Skateboard with control unit | |
US4138128A (en) | Ski board | |
EP0500991B1 (en) | Rollerboard for road-skiing | |
US4775162A (en) | Swingable skateboard | |
US20150239292A1 (en) | Recreational vehicle | |
US6331007B1 (en) | Sporting equipment binding apparatus | |
US20160375347A1 (en) | System And Method For Regulated And/Or Limited Speed Control | |
US20090066150A1 (en) | Cam Action Caster Assembly for Ride-On Devices | |
FR2593402A1 (en) | SPECIALIZED APPARATUS AND ACCESSORIES FOR INITIATION, TRAINING AND DEVELOPMENT IN ALPINE SKIING AND ITS TEACHING | |
US2865645A (en) | Roller skate having continuously applied braking means | |
US3000643A (en) | Controllable skate having continuously applied brake | |
US4092033A (en) | Skateboard having a flexible and resilient chassis with speed control means | |
US5372384A (en) | Ski-turn simulator | |
US6206389B1 (en) | Method and apparatus for surfable skateboards | |
US5397154A (en) | Stabilizer device for skiers | |
US10870459B2 (en) | Learning aid for central wheel structure auto-balancing device and auto-balancing device having same | |
CN101745213A (en) | Street board | |
US9504903B2 (en) | Braking apparatus for a recreational riding board apparatus | |
EP2337613A1 (en) | Rollerski or skate with braking system and method for braking said sports item | |
US3934893A (en) | Slalom ski device | |
US3729207A (en) | Snow ski training device | |
US2865644A (en) | Controllable skate having continuously applied brake | |
US2920899A (en) | Roller skate with small turning radius | |
US7156778B1 (en) | Motocross exerciser |