US3738673A

US3738673A - Roller skate construction

Info

Publication number: US3738673A
Application number: US00143950A
Authority: US
Inventors: R Iseman
Original assignee: Micro Star Skate Co Inc
Priority date: 1971-05-17
Filing date: 1971-05-17
Publication date: 1973-06-12
Anticipated expiration: 1990-06-12

Abstract

A roller skate construction comprising a first embodiment having a cast body member having first and second spaced bores therethrough, a pair of axles mounted in said bores with each of said axles being mounted on pins inclined to the vertical in opposite directions with ball bearings securing central portions of the axles on the pins, and rubber bushings on opposite sides of the axle and interposed between the body member and the wheels for providing resistance to turning of the axle in response to plate lean. A second embodiment journals the axle in a truck which is supported relative to the plate by a ball having its center on a line extending through the point of contact between the wheel and the floor and the center of the axle. A third embodiment mounts the axle on a truck which is connected to the plate body by a pair of spaced ball connections fore and aft of the axle with the resistance provided by the ball connections being such that lateral forces applied to the wheels at the floor cannot cause more turning of the wheel than corresponds to the plate lean then being effected. The skate construction also includes, as a modification, a plug insertable in the body member for mounting the pins for the axles of the first embodiment described above so that the angle which the pins make can be adjusted by rotating the position of the plug in the skate body member. The roller skate construction also includes an improved toe stop in which the bumper is mounted on a threaded shaft which is mounted into a split sleeve which is received into a split portion of the housing which can be clamped around the toe stop, with the sleeve always abutting a predetermined shoulder in the body member so that the toe stop can be removed and replaced quickly while maintaining the desired adjustments.

Description

Unite States Patent 1 Iseman ROLLER SKATE CONSTRUCTION Richard W. Iseman, Buffalo, N.Y.

[73] Assignees Micro-Star Skate Company, Inc.,

Lakeville, Conn.

[22] Filed: May 17, 1971 [21] Appl. No.: 143,950

[75] Inventor:

Primary Examiner-Leo Friaglia Assistant Examiner-Leslie J. Paperner Attorney-Sommer, Weber & Gastel [5 7] ABSTRACT A roller skate construction comprising a first embodiment having a cast body member having first and second spaced bores therethrough, a pair of axles mounted in said bores with each of said axles being mounted on pins inclined to the vertical in opposite directions with ball bearings securing central portions of the axles on the pins, and rubber bushings on opposite sides of the axle and interposed between the body member and the wheels for providing resistance to turning of the axle in response to plate lean. A second embodiment journals the axle in a truck which is supported relative to the plate by a ball having its center on a line extending through the point of contact between the wheel and the floor and the center of the axle. A third embodiment mounts the axle on a truck which is connected to the plate body by a pair of spaced ball connections fore and aft of the axle with the resistance provided by the ball connections being such that lateral forces applied to the wheels at the floor cannot cause more turning of the wheel than corresponds to the plate lean then being effected. The skate construction also includes, as a modification, a plug insertable in the body member for mounting the pins for the axles of the first embodiment described above so that the angle which the pins make can be adjusted by rotating the position of the plug in the skate body member. The roller skate construction also includes an improved toe stop in which the bumper is mounted on a threaded shaft which is mounted into a split sleeve which is received into a split portion of the housing which can be clamped around the toe stop, with the sleeve always abutting a predetermined shoulder in the body member so that the toe stop can be removed and replaced quickly while maintaining the desired adjustments.

12 Claims, 26 Drawing Figures mmcnwm 3.738.673

SHEET-1 9f 5 INVENTOR.

Aria/P443 PAIENIEDJuN 1 2 ma SHEEI30F5 1 ROLLER SKATE CONSTRUCTION The present invention relates to an improved roller skate construction.

By way of background, in roller skates, turning is effected by causing the skate plate on which the shoe is mounted to lean to the side about its longitudinal axis. This causes the front wheels to turn in a first direction and the rear wheels in the opposite direction so as to track with the front wheels and thus cause them to traverse a curve having a predetermined radius. Theoretically, when the front and rear wheels track properly, the skater should be able to traverse his desired curve without in any way varying his plate lean. However, as a practical matter, in one prior type of skate construction the radius of turn varied while the plate lean was maintained constant because the axles on which the wheels were mounted moved toward and away from each other as a result of being subjected to varying forces exerted on them through the skate plate. These varying forces were due to changing in the skaters speed while traversing a curve, shifting body weight from one skate to another, effecting jump take-offs and landings, effecting power pushes, and other such factors. This required that the skater constantly rock his foot from side to side in an attempt to compensate for the tendency for the skates to continuously change their radius of turning when subjected to the varying forces noted above. In other prior types of skate constructions, after the wheels were turned in the above mentioned opposite directions in response to leaning the plate, the above mentioned forces on the plate and the forces on the wheels at their points of contact with the floor caused the wheels to depart from their intended turning radius which also required that the skater compensate by varying the plate lean by rocking his foot from side to side. In short, in prior types of skate constructions constant compensation was required on the part of the skater in order to cause him to travel in a predetermined path without losing his aim. IN addition to the constant compensation which was required, In discussed in detail above, there were the related shortcomings that the skater in attempting to correct his aim could oversteer in certain instances. Furthermore, he could not travel as far with a given amount of power input because the constant changing of the path of movement increased the length of the path of travel. Furthermore, in certain circumstances there could even be ,a breaking of traction with the floor when the changing radius and attendant correction caused an extreme weaving which caused the skate to slide sideways rather than to roll on the floor. The above discussed loss of aim could occur, as noted above, when the front and rear wheels were adjusted to track properly. However, the loss of aim was further compounded when the front and rear wheels did not track properly. One reason for improper tracking between the front and rear wheels was that separate adjustments were provided for the front and rear wheels in prior type of skate constructions, and when these adjustments were made improperly by the skater, different amounts of wheel turn of the front and rear wheels occurred in response to plate lean, which also caused the skates to vary from the desired path of travel during turns. It is with overcoming the foregoing deficiencies of prior skate constructions that the present invention is concerned.

It is one object of the present invention to provide improved roller skate constructions which produce positive controlled equal and opposite turning of the front and rear wheels in response to the plate lean which is applied by the skater. A related object is to provide an improved roller skate construction in which the amount of wheel turning is solely a function of the plate lean and does not change with changes in speed and which is not influenced by forces which are applied to the plate and wheels during turning and in which the front and rear wheels track perfectly. A further related object of the present invention is to provide an improved roller skate construction which does not require the skater to compensate by pivoting his foot from side to side to maintain a proper aim, but which will hold to a predetermined turning radius under all conditions as long as the amount of plate lean is maintained constant.

Another object of the present invention is to provide an improved roller skate construction which cannot be adjusted by the skater and therefore always remains at a proper preset adjustment which cannot be varied and which therefore also always produces equal tracking between the front and rear wheels under all skating conditions.

A further object of the present invention is to provide an improved roller skate construction which can be disassembled and reassembled simply and quickly and be in proper adjustment incidental to the mere act of reassembling without requiring any skill on the part of the assembler, and in which the plate lean resistance will not be affected by the reassembling.

Yet another object of the present invention is to provide an improved roller skate construction in which the resistance to plate lean can be changed simply by merely replacing the rubber bushings which resist axle turning with rubber bushings of a different hardness. A related object of the present invention is to provide an improved roller skate construction in which the rubber bushings are of a configuration which will permit a relatively high preload for stabilization of the plate in a horizontal attitude and in which the amount of force does not become excessive for relatively high amounts of plate lean.

A still further object of the present invention is the provide an improved roller skate construction which can be fabricated from lightweight materials and therefore is sufficiently light to facilitate the skaters doing complicated maneuvers during competition, including jumps, fast footwork and spins.

Yet another object of the present invention is to provide an improved roller skate construction having an improved toe stop which can be inserted or removed from the skate body rapidly with a simple pull-out motion and when reinserted will maintain the same adjustment which it had when it was removed.

Another object of the present invention is to provide an improved roller skate construction having a cast or molded body member which eliminates excessive machining during fabrication, and in which all parts are positively located relative to each other because the body member is fabricated in one piece. Other objects and attendant advantages of the present invention can readily be perceived hereafter.

The improved roller skate construction of the present invention comprises plate means having a longitudinal axis and an upper side and a lower side, an axle having opposite ends for mounting wheels, and mounting means for mounting said axle for rotation solely about a fixed central point and solely in response to varying the amount of lean to which said plate means is subjected while preventing changing of said angle in response to lateral forces applied to said wheels and said plate other than those forces required to effect the plate lean. The foregoing can be achieved by a number of different modifications. The present invention also includes an improved toe stop construction which can be slipped into or out of the skate body rapidly with great ease and perfectly reliability as to alignment.

The various aspects of the present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of the improved roller skate construction of the present invention mounted on a shoe;

FIG. 2 is a plan view of the roller skate construction of FIG. 1 looking upwardly at the sole of the shoe;

FIG. 2A is a fragmentary view taken in the direction of arrows 2A-2A;

FIG. 3 is a fragmentary cross sectional view taken substantially along line 3-3 of FIG. 2 and showing the manner in which the wheel axles and the toe stop are mounted on the body member;

FIG. 4 is a fragmentary cross sectional view taken substantially along line 4-4 of FIG. 3 and showing the structure for securing the toe stop in position;

FIG. 5 is a fragmentary cross sectional view taken substantially along line 5-5 of FIG. 3;

FIG. 6 is a fragmentary cross sectional view taken substantially along line 6-6 of FIG. 3;

FIG. 7 is a fragmentary side elevational view taken substantially along line 7-7 of FIG. 8 and showing a modified construction for permitting the adjustment of the axis about which the axle turns;

FIG. 8 is a fragmentary cross sectional view taken substantially along line 8-8 of FIG. 7;

FIG. 8A is a side elevational view of the axle used in the embodiment of FIG. 8;

FIG. 8B is a view of the axle of FIG. 8A rotated 90";

FIG. 9 is a fragmentary cross sectional view taken substantially along line 9-9 of FIG. 8;

FIG. 10 discloses a modified form of the present invention which utilizes frustoconical helical spring overlays on the rubber bushings to limit the amount of wheel turn;

FIG. 11 is a view similar to FIG. 10 but illustrating the mode of operation of the subject matter of FIG. 10;

FIG. 12 is a fragmentary cross sectional view taken substantially along line 12-12 of FIG. 14 and showing an alternate modification of the present invention which prevents wheel turning due to side forces applied to the wheel;

FIG. 13 is a fragmentary cross sectional view taken substantially along line 13-13 of FIG. 12;

FIG. 14 is a rear elevational view taken in the direction of arrows 14-14 of FIG. 12;

FIG. 15 is a fragmentary cross sectional view taken substantially along line 15-15 of FIG. 16 and showing an alternate construction for providing positive steering control without being influenced by lateral forces applied to the wheel;

FIG. 16 is a rear elevational view of the subject matter of FIG. 15 taken substantially along arrows 16-16 of FIG. 15;

FIG. 17 is a schematic view showing the angles which the front and rear wheels will assume during a turn when both the front and rear axles pivot the same amount;

FIG. 18 is a schematic view showing the angles which the front and rear wheels assume when the axles on which they are mounted pivot different amounts;

FIG. 19 is a side elevational view of a roller skate construction in which the truck is resiliently mounted on rubber cushions in such a manner that the wheel turn angle can be influenced by lateral forces applied to the wheels;

FIG. 20 is a fragmentary cross sectional view taken substantially along line 20-20 of FIG. 19 and illustrating how the lateral forces applied to the wheels can affect the steering angle; and

FIGS. 21, 22 and 23 show diagrammatically how the turning angle for the wheels increases with greater plate lean angles.

The improved skate 10 of the present invention is adapted to be mounted on a shoe 11 having a sole 12 by means of rear spaced bolts 14 and front spaced bolts 15 which extend through heel l6 and sole 12, respectively.

Bolts

14 and 15 also extend through plate 17 which includes portions 18 extending outwardly from body member 19.

Nuts

14 and 15 secure the skate 10 securely in position.

The body member 19 and plate 17 are cast integrally from aluminum or magnesium or any other suitable material which can also be plastic, such as nylon. By casting the foregoing member 19, machining and assembling operations are decreased and the weight can be held relatively low. For example, the weight of each casting in aluminum is 19 ounces, in magnesium is 12 ounces, and in nylon is 7 ounces. It will be appreciated that by lessening the weight of body member 19, the skaters performing fast and intricate skating maneuvers, such as jumps and spins, is facilitated.

Preferably a plastic film 20 can be mounted on member 19 so that it covers all exposed parts of the housing portion 19 and the underside and edges of plate 17, thereby obviating the necessity for polishing the basic casting. This plastic can be of the type which is vacuum formed and slipped over the housing portion 19 prior to the mounting of the axles and wheels thereon. Furthermore, this plastic can be prechromed to provide the desired shiny effect.

The housing member 19 includes a front bore 21 and a rear bore 22 which are formed during the casting process. Both of these bores extend entirely through the

portions

23 and 24 of the housing member 19, as can be seen from FIGS. 5 and 6. Furthermore, bore 21 is identical to bore 22 except that each is inclined at the same angle but in an opposite direction to the vertical, as can best be seen from FIG. 3. The axles 25 which are inserted through

bores

21 and 22 are identical and it can therefore be considered that FIGS. 5 and 6 are different views of the same axle 25. Each axle 25 includes a central plate-like portion 26 having an aperture 27 therein. Bores 28 are located on opposite sides of plate 26 and receive the outer races 29 of ball bearings 30 with a press fit. The inner races 31 are separated by spacer member 32. A pin 33 in the nature of a bolt extends upwardly through

bores

34 and 35 in front housing portion 23. Bolt head 36, which may be formed to receive a hexagonal wrench in opening 37, bears against sleeve 38 which in turn bears against the inner race 31 next to which it islocated. The inner race of the opposite bearing bears against washer 39 which is held against wall 40 of bore 21. A hexagonal nut 41 is received in hexagonal bore 42 in body portion 23 and threads onto threaded end 43 of bolt 33. It will be appreciated that by inserting a hexagonal wrench into opening 37, bolt 33 may be rotated to secure nut 41 firmly thereon and whenthe nut 41 is tightened to its fullest amount, the central portion of axle 25 will be mounted on ball bearings for pivotal movement about the axis of pin member 33. A pin member 33 which is analogous to pin 33, mounts the rear axle 25 on rear housing portion 24 in the same manner. The primed numerals on bolt 33 and on housing portion 24 correspond to the parts associated with bolt 33 and housing portion 23, respectively, which are unprimed. Central portion 28' of axle 25 which houses the bearings merges into enlarged axle portions 44 which in turn merge into outer reduced axle portions 45 which are threaded at their outer ends 46. Bec se .of the ball bearing mounting of the axles in the above described manner, there is no looseness in the fit, except for the rotation, and therefore the axles willtn solely in response Plate an u not in r sponse to th r fa tors, as will become more apparent hereafter.

The front body portion 23 has a pair of circular depressions 4 in an th ee body po ion 24 ha a pair of circular depressions 48 therein on opposite sides thereefe' h e g d nd 9 o subs antial y frustoconical rubber bushings 50 are seated i d pressions 47 and 4 8. AperturesS in the bushings seat on enlarged shaft portions 44 and concaye portions 51' ag the ou e p t o of oiising 28'- he out ends 52 of u hing 50 a en aged by wash 5 which are mounted on reduced end portions 45 of the e d shu h shou de b ween th tetluee end Portion 45 nd the nla g d axle po tions 44 adj cent thereto. Front wheels 54-are mounted on reduced axle Portions 5 by a s f spa ed he" hearings 55 and h h el a e h l in position by means o l locking nuts 56 which thread onto threaded axle portiehs It will h eppreei iteilth t s nc th imit o movement of washer 53 is defined by the shoulder 44 and since h ei h of rilsteeoniesl bushing i a predetermined m u bushin 59 will he eoinpr s eti prem ne hot ht eiltoihetieelly ncidental to the m y PrQ e S- e hee 57 r mounted in a manher identical o ont heels 54 end herefore a d tail d description is o de m d nec ssary anti therefore w l be edh le ball bearin s heye been show in G -6 for mounting axles 215, it w ll he enpr e eted at other ypes f b aring een be used- Reference is now made to FIGS. 17 and As is well d r t in he rt hee hse pi 33 end. 3 G: 3) are n i e o e v rti al qually anti opposi ely, h n t a e causes p ate 7 o t ch es in S- -2 he a l or the front Wh ls 4 will him a given m nt in a fitdi tlon to assum an angl a i h o tud nal axis 58 of Pla 17 an h axle for the rear wheels will turn in the opposite direction to assume h shal a w th th onsit lihel a i 58- A noted a e. h angl whi h th a l s sssilme pend on the amount of plate lean and increases with increases in plate lean as is shown progressively in FIGS. 21-23. Since the axles 25 are mounted hy ball bearings 6 of axles 25, there can be no variation in the inclination of angles a. Therefore, the

wheels

54 and 57 will both be turning about a given center C (FIG. 17) so that they will provide a true tracking action. In other words,

wheels 57 will follow the same path set by wheels 54. Therefore, there will be no side slip or drag due to un- .cqual tracking of the front and rear wheels which could result in sidewise dragging or slipping of one set of wheels or both setswhich in turn could cause breaking of traction with the floor which in turn ,could cause the skater to fall or lose his balance or lose his aim. In addition, if there'is improper tracking of rear wheels 57 with front wheels 54, there will be undesired slowdown of skater movement because of the dragging action of the wheels. It is also to be noted that since the axles do not move toward or away from each other at their centers, the radius of turn will remain constant for a given amount of plate lean. In contrast, in constructions where the axles move toward or away from each other at their centers due to varying forces on the plate, the radius of turning will change, thus requiring the skater to compensate by rocking his foot from side to side to vary plate lean.

The foregoing can be more fully understood by cornparing the action of the skate shown in FIG. 17 with the action of a prior type of skate such as shown in FIG. 18 which do not produce equal tracking and wherein the front wheels 54 turn about a center at D and the rear wheels 57' turn about a center at E which effectively indicates that the front wheels 54' are turning about a t ad u nd t tear whee s 57' are turning about a second radius which differs in length'from the first radius. This being the case, the rear wheels 57 will track inside the front wh els 54. It will be appreciated that h mproper r cki g between the fr n wheels 54 and. th rea wh l 5 s this to the fact that the an le b is greater than angle b which causes one of the sets of wheels to drag somewhat.

s no e a o in accordance with the imp oved ons ruction hown i FIG 1-5, the ront and r axles will always turn the same exact amount but in opposite directions in response to each predetermined mo nt o p a h art. that is, the angl which plate 7 makes with the horizontal in FIGS. 21-23. Furthermore, there is no requirement for adjusting of the front nd ear whe ls nd id ally, a was required in other types of constructions. In other words, the present cons rtt tion gives positively controlled wheel turnin Which is proportional to plate lean and is in no way influenced by forces which are exerted on the skate plate and wheels during skating. The varying forces on the p a ar due to ha g s in peed while negotiatin a curve, changes in the amount Of force exerted by the skaters feet on the plate as he shifts his weight, effecthis po r pushe jump ta e-offs and landings, and other factors. In addition,

wheels

54 and 57 are subj ct ti to la eral orces u h a 6.1 and 62 which exist at e poin of contact between th whe l and the flo r. However, since the center of pivotal movement of axles 25 is in line i h the direction of forces .61 and 62, these forces cannot exert a turning moment on the axles which tend to turn, them more than is required by the plate lean. In other words,

forces

61 and 62 do not act through a lever arm tending to produce a turning moment turning the axle more than they have to turn by the plate lean. This will be more fully appreciated when other constructions are discussed hereafter at appropriate parts of this specification. Stated another way, the manner in which axles 25 are mounted eliminates uncontrolled wheel turning resulting from side forces such as 61 and 62 exerted on wheels 54 and 57 (FIG. 17). These side forces may be due to such factors as the resistance to centrifugal forces resulting from skating around a curve, forces occurring both at jump take-offs and landings, twisting forces on the plate due to body rotation, twisting and sliding forces resulting from one foot turns, and forces due to changes in speed while negotiating a curve.

At this point it is to be noted that rubber or resilient bushings 50 function merely to resist turning of axles 25 and function additionally to return the axles 25 to a position where they extend substantially perpendicularly to the longitudinal axis of plate 17 when turning is not being effected. At this point it is to be noted that bushings 50 can be provided in a number of different hardnesses so that the plates have for example a lower leaning pressure, an intermediate leaning pressure, or a harder leaning pressure, as desired by the particular skater who owns the skates. Furthermore, it is to be especially noted as discussed above, that since the distance between the face 47 of depression 47 and shoulder 44' is fixed, the tightening of a wheel such as 54 onto axle 25 will always provide the same amount of compression of bushing 50. Therefore, changing of the resistance provided by a given set of bushings 50 is not within the scope of an adjustment. Furthermore, the frustoconical configuration of bushings 50 permits a greater length of rubber to be used which in turn will accept a greater amount of preloading without excessively limiting the amount that bushings 50 will compress further. In other words, by using relatively long and thin walled bushings 50 of the frustoconical configuration shown, the compression resistance of the bushings 50 will increase at a relatively low rate which will provide a relatively low amount of pressure buildup per unit of plate lean while permitting a relatively high amount of preloading for increasing the stability of the plate in a horizontal position.

The improved skate includes an improved toe stop construction 62' which comprises a round rubber bumper 63 of the configuration shown in FIGS. 1, 2 and 3 having the lower portion of a threaded stem 64 embedded therein. A tapped sleeve 65 receives the upper threaded end of stem 64 to any amount which is required or desired by a skater. In other words, the skater can screw stem 64 into sleeve 65 any required distance before sleeve 65 is slid longitudinally into bore 66 in housing portion 19. A shoulder 67 (FIG. 3) is located at the upper end of bore 66 to receive the end of sleeve 65 in abutting relationship. Thus, sliding sleeve 65 into bore 66 automatically locates bumper 63 at the desired location. Sleeve 65 is split longitudinally at 67' throughout its length so that when nut 68 is tightened onto bolt 69, which extends through bore 69', the

housing halves

70 and 71 which are separated by split 72 are drawn together to clamp stem 64 securely in position so that it cannot move into or out of bore 66. Whenever it is desired to remove toe stop 62, it is merely necessary to loosen nut 68 to permit instant withdrawal of the entire unit including stem 64 and sleeve 65. Upon reinserting the unit, the bumper 63 will always occupy the same location which it occupied previously. If for any reason it is desired to change the position of bumper 63 relative to the remainder of housing 19, it is merely necessary to remove stem 64 and sleeve 65 and adjust the relative axial positions thereof before reinserting sleeve 66 into the housing member 19.

In FIGS. 10 and 11 a modified form of bushing arrangement is shown. Wheels 54 are mounted in the identical manner as those described above relative to FIGS. 1-5 and resilient rubber bushings 50 are identical to those described above. However, in this modification frustoconical helical springs 73 are placed in overlying relationship to bumpers 50 with the inner ends of the springs pressing against the body member 19 and the outer ends pressing against washers 53. Normally the springs 73 will merely add only a low rate increment of resistance against turning of the axle. However, as can be seen from FIG. 11, once a predetermined degree of wheel turn has been realized, the successive coils at the

compressed spring portions

74 and 75 will engage each other to provide a solid stop which prevents further turning movement. In other words, coil springs 73 function primarily as a positive stop mechanism without requiring external abutments or the like which might not operate as effectively. Furthermore, the positive stop mechanism permits the use of relatively-soft rubber bushings for faster foot work, less foot fatigue and better control without permitting the plate to contact the wheels.

In FIGS. 12-16 alternate embodiments of the invention shown in FIGS. 1-5 are set forth. In FIGS. 12, 13 and 14 a first embodiment is shown wherein plate 76 includes a central underslung portion 77 having a partially spherical socket 78 for receiving spherical ball 79 mounted at the end of screw 80 which has its lower portion threaded into the upstanding portion 81 of truck 82 which in turn journals axle 83 which mounts spaced wheels 84. The truck 82 includes a laterally extending arm portion 85 which is bracketed by resilient rubber lower and

upper bushings

86 and 87. An action bolt 88 extends upwardly through washer plate 89, busing 86, aperture 90 in truck arm portion 85, bushing 87, and washer 91, and is threaded into portion 92 which is an extension of portion 77. A nut 93 is threaded onto the threaded portion of the bolt so that by tightening nut 93 upwardly to lock bolt 93 in position an expansion pin 94 locates bolt 88. Pin 94 extends through aligned holes in portion 92 and bolt 88. Expansion pin 81' extends through aligned holes in bolt 80 and truck 81 to lock bolt 80 against movement. As can be seen from FIG. 12, if a lateral force extending into the plane of the drawing should be applied at point F, that is the point at which the wheel engages the floor, there will be no lever arm for this force to act through with respect to the center of ball 79 about which truck 82 essentially rotates, and therefore this lateral force will not contribute to changing the turn angle or angle to which the axle has been moved by the plate lean. In other words, in this particular embodiment when the plate 76 is tilted or caused to lean by the pressure of a skaters foot, the action bolt 88 will act through

bushings

86 and 87 to pivot truck extension 85 into or out of the plane of the drawing in FIG. 12 and this will rotate the truck essentially about the center of ball 79, which remains fixed relative to the plate 76, and the rotation of the truck will change the angle which axle 83 makes with the longitudinal axis of plate 76. However, any lateral forces applied at point F will not provide a turning moment and therefore in this construction lateral forces applied to wheel 84 at F will not change the angle to which the wheels have been turned by plate lean. Furthermore, thefront and rear wheels will not approach or recede fromeach other in this construction so as to vary the radius of turning.

ln FIGS. and 16 a still further embodiment of the present invention is disclosed. This embodiment includes a plate 97 having an underslung portion 98 depending therefrom. A truck 99 journals axle 100 which mounts a pair of spaced wheels 101. One end 102 of the truck receives the threaded end 103' of pin 104 which is locked in position by nut 105. An expansion pin 103' extends through aligned holes in bolt 104 and truckportion 102 to further secure bolt 1 04 in position. The upper end of pin 104 mounts a spherical ball bearing construction 106 having an inner race 107 mounted on pin 104 and an outer race 108 pressed into skate portion 98. The substantially horizontal arm portion 109 of truck 102, which is analogous to portion 85 of FIG. 12, receives an action bolt 110 which extends through rubber bushings 111 and 1 12 on opposite sides of arm portion 109. Bolt 110 has an upper threaded end 113 which is received in mating tapped portion 114 of underslung member 98. The action bolt 110 also extends through

caps

115 and 116 on opposite sides of bushings 111 and 112 A spherical ball bearing 117 includes an inner race 118 in which action bolt 110 is slidably mounted and an outer race 119 which is pressfitted into truck portion 109. Bushing 111' fits tightly between inner race 118 and cap 115, and bushing 112 fits tightly between inner race 118 and cap 116,

It will be appreciated that when action bolt 110 is properly tightened, truck 99 cannot be moved by lateral pressures applied at M in a direction extending into the plane of the drawing because of the fact that the spherical bearing 117 provides a sufficiently tight fit between truck arm 109 and action bolt 110 so that there'is a greater'force tending to hold the truck arm 109 against movement laterally than, any force which can be applied at M. In other words, the force at M tends to work through a lever arm 120 tending to pivot truck arm 109 about the center of spherical bearing 106, and the forceresisting this turning movement is applied at the center of spherical bearing 1 17 and acts ugh a l a .2 Ths s sting b rse appl ed at the center of spherical bearing 117 by action bolt 110 is sufficiently great so that the force M cannot turn the truck.

ber bushings 111 and 112 are compressed is limited by the length of the bushings 111' and l 12'. Therefore the pressure on bushings 111' and 112 is automatically maintained at'a predetermined value.

If it is desired to change the distance of the center of axle 100 from the top of plate 97, to change the action angle c, that is the angle between the horizontal and a line 99' through the centers of

bearings

106 and 117, it is merely necessary'to substitute a longer or shorter bushing for bushing 112. Also, if it is desired to vary the distance between the axis of axle 100 and plate 97, this can be done by loosening nut 105, screwing screw 104 into or out of truck 99 and thereafter retightening nut 105.

The improved action of the embodiments of FIGS. 12-16 .can be more fully appreciated when they are compared to the conventional type of structure shown in FIGS. 19 and 20 which do not have the necessary resistance to lateral forces which can change. the amount of wheel turn. In this respect plate includes a depending portion 126 having a socket 127 which receives ball 128 located at the end of screw 129 which threads into portion 130 of truck 131 which journals axle 132. A truck arm portion 133 receivesaction bolt 134 which also extends through

resilient rubber bushings

135 and 136 which lie between

washers

137 and 138, with action bolt 134 being threaded into portion 139 of underslung portion 126. As can be seen from FIG. 19, truck portion arm 133 includes an enlarged aperture 140 through which action bolt 134 extends. In this embodiment, which is representative of the prior art, a lateral force applied at N extending into the plane of the paper in FIG. 19 will cause truck portion 133 to moveinto the plane of the drawing about ball 128 as a center in FIG. 19 or upwardly in FIG. 20. This is possible because

bushings

136 and 135 will yield to permit this, as shown in FIG. 20. When this occurs the wheels 141 will turn more than that corresponding to the existing plate lean because of the lateral force applied at point N will cause truck portion 133to continue to swing laterally against the, bias of the

resilient bushings

135 and 136 which do not have enough resistance to prevent the wheels from turning when the lateral forces N are applied. In contrast to this, it can be seen that the embodiment of FIGS. 15 and 16 does have this type of resistance as explained in detail above. Furthermore, in

In the odiment of FIGS- 15 nd. .6, h n y y h truck 99 ca e moved s by tilting Plate 7, h changing its angle f ean wh h in turn chang e i ati of action bo 0 la i e o trns a m. .0 s or e p y sen g he l r end o a on b to tilt more into or out of the plane of the drawing in 15 o o he ig or ef n F G-v .,ant s a on will P vo truck .2 as i also mo es relativ t bsaring 10 h eg ng action sen b qbtainstl. by irtue o e ph c n t of bssting lt fitns. ssn f wh provides f sd po n abou which axis l0!) pi o s, t will be appr sia sd of cou se that bear ng 106 and 1 need not necessarily be ball bearings but may be any other yp of sr hsr s l e tings t l e app e ated tha hen astinn bo t ,10 i

I tightened as far as it can be, that is when extension 98' the embodiment of FIGS. l2-14 there need be no resistance because the force F has no lever arm through ball 79, Furthermore, in the pastin order to avoid the type of action described above with respect to FIGS. 19 and 20, the skater tightened up the action bolt to compress the

bushings

135 and 136, and when this was done the resilient rubber bushings such as 135 and 136 associated with the front and rear trucks were usually not tightened up equally and therefore a given amount of plate lean would cause the front and rear wheels to turn unequally which in turn gave rise to the improper tracking described above with respect to FIG. 18 and all the attendant shortcomings flowing therefrom.

In FIGS. 7, 8 and 9 a modified embodiment of the present invention is shown which essentially incorporates the basic axle structure of FIGS. 1-5 but provides an adjustment for the angle about which the axle pivots. More specifically, in this embodiment the skate housing includes a tapered bore 151 therein which receives a frustoconical plug 152. The plug is held in a given adjusted position by means of a bolt 153 which extends through bore 154 and has its head 155 recessed in bore 156. A nut 157 threads onto the threaded end of bolt 153 and is received in bore 158. As can be seen from FIG. 7, the bolt head 155 fits into a scallop 159 on the plug periphery and thus holds the plug 152 in a given position. If it is desired to change the circumferential position of plug 152, it is merely necessary to remove bolt 153, loosen plug 152 (after wheels 175 and bushings 176 are removed) and rotate it so that after the bolt 153 is reinserted it will be received in

scallop portion

160 or 161. Thus, the axis of bolt 170 (FIG. 9)

about which axle 162 pivots will be changed to cause the skate to give a different turning response than which it gave when the bolt head 155 was received in scallop 159. i

The axle 162 is received in plug 152 in the following manner: A ball bearing 163 is inserted so that its outer race is press fitted into bore wall 164 after having been inserted through bore 165. Thereafter, axle 162 is inserted lengthwise through slot 166 until aperture 168 in flat central portion 162' of axle 162 is in alignment with aperture 169 in the inner race of bearing 163. A bolt 170 is inserted through bore 171 in plug 152 and through aligned

apertures

169 and 168. Thereafter a bearing 172 has its outer race press fitted into bore 165 with the opening 173 in its inner race mounted on bolt 170. A nut 174 secures bolt 170 in position so that it is mounted on the inner races of

bearings

163 and 172 and extends through bore 168 of axle 162.

To complete the mounting of wheels 175 on axle 162, frustoconical resilient rubber bushings 176 are mounted on enlarged portions 177 of axle 162 so that the larger portions of bushings 176 are received in

recesses

177 and 178 of the housing on opposite sides of plug 152. It is to be noted that the bushings seat against axle shoulders 179. Thereafter washers 180 are mounted on axle shoulders 179. Thereafter washers 180 are mounted on axle 162 until they abut shoulders 181. Thereafter the wheels 175 are mounted on reduced end portions 182 of the axle and a suitable nut 56, such as shown in FIGS. 3-5, is used to secure wheels 175 in place. It is to be noted that since the distance between each shoulder 181 and the adjacent face of plug 152 is fixed, the amount of compression to which bushing 176 can be subjected is predetermined.

It can thus be seen that by manipulation of plug 152 so that nut head 155 is received in any of the

scallops

159, 160 or 161, as desired, the axis of bolt 170 can be changed to thereby change the axis about which axle 162 pivots, thereby to change the ratio of plate lean to wheel turn of the skates, as desired. While only the rear axle mounting has been shown in FIGS. 7-9, it will be appreciated that the same type of adjustable mounting can be used for the front axle of the skate.

What is claimed is:

1. A roller skate construction comprising plate means having a first longitudinal axis relative to which said plate means is pivoted to vary the amount of lean thereof, an axle having a second longitudinal axis extending transversely to said first longitudinal axis and having opposite ends for mounting wheels, and mounting means for mounting said axle for pivotal movement relative to said plate means solely about a fixed point centrally located on said second longitudinal axis in response to varying the amount of lean to which said plate means is subjected, said mounting means including means for preventing movement of said fixed point relative to said plate means, whereby lateral forces applied to said wheels at the point of engagement of said wheels with the ground will not influence plate lean and whereby a given amount of plate lean will always produce a predetermined angle between said first and second axes.

2. A roller skate construction as set forth in claim 1 wherein said mounting means include a body member extending downwardly from said plate means, pin

means on said body member extending at an angle to.

the vertical for securing said axle thereto, said pin means including a third longitudinal axis which intersects said second longitudinal axis at said fixed point, and bearing means mounting said axle for pivotal movement relative to said body member.

3. A roller skate construction as set forth in claim 2 wherein said means included in said mounting means comprises means for mounting said pin means and said axle against longitudinal movement along said third axis.

4. A roller skate construction as set forth in claim 3 including a second body member secured to said plate in spaced relationship along said first longitudinal axis from said first body member, a second axle having a fourth longitudinal axis and having opposite ends for mounting wheels, second pin means on said second body member for securing said second axle to said second body member, said second pin means extending at an equal and opposite angle to the vertical as said pin means, said second pin means including a fifth longitudinal axis which intersects said fourth longitudinal axis at a second fixed point, said fixed point and said second fixed point lying along said first longitudinal axis.

5. A roller skate construction as set forth in claim 2 wherein said axle has a central portion with an aperture located therein and wherein said pin means extends through said aperture and wherein said bearing means mounts said axle on said pin means.

6. A roller skate construction as set forth in claim 2 including adjusting means for adjusting the angle which said pin means makes with the said plate means.

7. A roller skate construction as set forth in claim 6 wherein said adjusting means comprises plug means having a plug axis extending transversely to said longitudinal axis, means mounting said pin means on said plug means, said plug means being rotatable about said plug axis to thereby vary the angle of said pin means, and means for securing said plug means in the position to which it has been rotated.

8. A roller skate construction as set forth in claim 2 including resilient bushing means mounted on said axle on opposite sides of said central portion and having first portions in abutting engagement with said body member and second portions in effective engagement with said wheels.

9. A roller skate construction as set forth in claim 8 wherein said bearing means are ball bearings mounting said axle on said pin means.

10. A roller skate construction as set forth in claim 8 wherein the distance between said first and second portions of each bushing is a predetermined amount, and wherein means are located on said axle a predetermined distance from said fixed point for limiting the distance said wheels may move onto said axle, whereby said resilient bushing means are always placed in the same amount of compression when said wheels are tightened on said axle.

14 of rotation to permit said bushing means to fit on said axle with said axis of rotation coincident with said second longitudinal axis, said bushing means having a larger base and a smaller base with said larger base in effective abutting engagement with said body member.

Po-wfib UNITED STATES PATENT OFFICE CERTIFICATE OF' CORRECTION Patent No. I 3,738,673 Dated June 12, 1973 Inventor-(s) W- Iseman It is certified that error appears in the above-identified patent and that. said Letters Patent are hereby corrected as shown below:

Column lfline 42 change "In" to as-.

Column 2} line 44, change "is the" to -is to--.

Column 8;, line 38, change "busing" to -bushing Column ll, lines 36 and 37, cancel sentence, "Thereafter washers 180 are mounted on axle shoulders 179.

Column 112 "line 21 (claim 4), change "claim 3" to -claim 2.-.

Signed and sealed this 5th day of March 19%..

(SEAL) Attes-t: v

EDWARD M .FLETCT'TER JR. c MARSHALL DANN- Attestlng fFFB Commissioner of Patents

Claims

2. A roller skate construction as set forth in claim 1 wherein said mounting means include a body member extending downwardly from said plate means, pin means on said body member extending at an angle to the vertical for securing said axle thereto, said pin means including a third longitudinal axis which intersects said second longitudinal axis at said fixed point, and bearing means mounting said axle for pivotal movement relative to said body member.

11. A roller skate construction as set forth in claim 10 wherein said bearing means are ball bearings mounting said axle on said pin means.

12. A roller skate construction as set forth in claim 10 wherein said resilient bushing means are frustoconical in shape and have an axis of rotation, and aperture means in said bushing means coincident with said axis of rotation to permit said bushing means to fit on said axle with said axis of rotation coincident with said second longitudinal axis, said bushing means having a larger base and a smaller base with said larger base in effective abutting engagement with said body member.