EP0997170A2

EP0997170A2 - Roller skate with elastic suspension means

Info

Publication number: EP0997170A2
Application number: EP99117526A
Authority: EP
Inventors: Tiziano Nava; Luca Poggiali; Giovanni Zaffaroni
Original assignee: Fbc Di Giuliano Frati & Csnc
Current assignee: Fbc Di Giuliano Frati & Csnc
Priority date: 1998-10-28
Filing date: 1999-09-04
Publication date: 2000-05-03
Also published as: ITPN980077A1; EP0997170A3; IT1305278B1

Abstract

Roller skate, in particular roller skate with in-line wheels, provided with independent elastic suspension means.

The wheels (11) are journaled in a bogie (13) that is floating with respect to the frame (12) of the skate (10), and are associated to pairs of springs (24) that are compressed between the frame and the bogie.

The solution is more rational, simpler and more compact with respect to prior-art ones.

Description

The present invention refers to a roller skate, in particular a roller skate with in-line wheels, provided with independent elastic suspension means.
The application of elastic suspension means to roller skates has already been proposed in the past in order to reduce shocks and vibrations transmitted during runs to the limbs of the skater owing to the irregularities of the terrain. Such stresses can in fact only be absorbed to a quite limited extent by the resilience of the wheels themselves, particularly when the roughness of the ground is rather significant, such as in the case of typical road surfaces.
The stresses are transmitted from the wheel to the limbs of the skater through the rigid frame on which the wheels are pivotally mounted. These stresses are both of an impulsive type (owing to shocks that occur when the skate gets off and then falls back onto the ground) and of a vibratory type at different vibration frequencies (during regular runs with the wheels adhering to the ground). This results in a skater undergoing increased fatigue with a corresponding decay in the efficiency and, hence, the performance thereof.
The US patent no. 2,552,987, patented in 1951, already describes an in-line roller skate, in which each wheel is journaled at the center of two brackets forming a fork that is mounted elastically on the frame of the skate. The brackets have an end portion thereof that is pivotally attached to the frame and the other end potion thereof that is connected to the frame through a spring which is in an in-line arrangement with the wheels, but does not lie on the same vertical axis of the respective wheel. Such a solution carries a number of drawbacks with it. In the first place, it leads to a useless and inconvenient elongation of the frame of the skate, brought about by the multiplicity of wheels and springs that are mounted in an in-line arrangement. Furthermore, the width of the bogie at the point where the wheels are journaled is the same as the width of the same bogie at the point where the brackets are pivotally attached to the frame, so that the skate turns out to be very sensitive to possible vibrations in a direction which is orthogonal to the rolling direction. Finally, the elastic suspension characteristics of the skate can be adjusted to fit the physical structure of the skater, but this can only be done by correspondingly replacing all of the springs.
The US patents nos. 5,503,413 and 5,582,418, which have been patented much more recently, both describe in-line roller skates that are provided with elastic suspension means which are not, however, independent, ie. are not provided individually for each wheel. Also these solutions have substantially the same drawbacks as the ones indicated in connection with the afore cited patent. Furthermore, the skates turn out to be more complicated and much less compact in their construction, since their suspension means develop to a considerable height.
The US patent no. 5,575,489 describes a roller skate with in-line wheels mounted elastically on the frame. Each wheel is connected to the frame by means of an axle, while on both sides of the wheel there are mounted respective elastic means, in particular springs, that are inserted in appropriate cavities of the frame and act against the end portion of the axle. The main drawback of this solution derives from the fact that the elastic means act directly against the axle of the wheel also in a differential manner, thereby bringing about a considerable instability of the skate. Furthermore, other drawbacks can be noticed to still persist, such as for instance the practical impossibility for the suspensions to be adjusted without first replacing the elastic means.
It therefore is a main purpose of the present invention to provide a roller skate, in particular a roller skate with in-line wheels, provided with elastic suspension means which is more rational, simpler and more and compact, both lengthwise and widthwise, than prior-art roller skates. A further purpose of the present invention is to provide suspensions means that are capable of being adjusted, without any need arising for the elastic elements to be replaced, in order to easily adapt them to fit the characteristics of both the skater and the rolling ground.
These aims according to the present invention are reached in a roller skate comprising a rigid frame in which there are journaled a plurality of wheels in an in-line arrangement, so as to be capable of rotating about respective horizontal axes, wherein each wheel is associated to a pair of vertical-axis compression springs that mounted at the sides of the same wheel and act against the frame of the skate. According to the present invention, the skate is substantially characterized in that each wheel is journaled in the lower end portion of a floating bogie whose upper end portion is hinged on to the frame of the skate, whereas each spring of said pairs of springs is compressed between the frame and the lower end portion of the bogie on which the respective wheel is journaled.
Features and advantages of the present invention will be more clearly and readily understood from the description that is given below by way of non-limiting example with reference to the accompanying drawings, in which:

Figure 1 is a schematical side view of a skate according to the present invention;
Figure 2 is a schematical top view of the frame of the skate illustrated in Figure 1;
Figure 3 is a view along the A-A section of a detail of the skate illustrated in Figure 1; and
Figure 4 is a view along the B-B section of another detail of the skate illustrated in Figure 1.

The skate 10 according to the present invention, and illustrated in the Figures, is a skate with five wheels 11 provided in an in-line arrangement and journaled on a rigid frame 12 (Figs. 1 and 2). The actual number of the wheels of the skate, however, is not critical or binding.
Each wheel 11 is provided with independent elastic suspension means and is connected to the frame 12 through a floating bogie 13. Each bogie 13 is formed by two arms 14 (Figs. 3 and 4), the lower end portions of which are connected to each other by a horizontal-axis axle 15 arranged orthogonally to the frame 12. On said axle 15 there is rotatably mounted the respective wheel 11 which therefore comes to lie at the center between the arms 14 of the bogie 13. The axle 15 is provided with a screw head portion 16 or may otherwise be threaded so as to allow for the wheel 11 to be quickly assembled and removed.
The upper end portions of the arms 14 of each bogie 13 are pivotally connected to a horizontal-axis axle 17 passing through the frame 12 in a direction that is orthogonal to such a frame 12. Each axle 17 is provided with a locking head 18 that enables each bogie to retain its position and alignment with respect to all other bogies of the other wheels 11. To this purpose, the through-passing axle 17 is provided with a shoulder 19 adapted to abut against a check 20 provided in correspondence of the bore through which the axle 17 passes through the frame 12 (Figure 4).
An important feature, as this will more clearly emerge further on, is the fact that the axis of each axle 17 lies at a lower level than the one of the upper extremity of the circumference or rim of the respective wheel 11. The frame 12 of the skate is preferably made using a C-shaped profile section with its flanges facing downwards, and is provided on its upper flat portion 30 with a plurality of through-apertures 21 (Figure 2). Each such aperture 21 corresponds to a wheel 11. The shape and the dimensions of the bogies 13 carrying the wheels 11 are such as to enable the upper extremity of the circumference or rim of each wheel to extend upwards beyond the surface of the frame 12 by passing through the corresponding aperture 21. Two resting means 22 and 23 (Figures 1 and 4) are provided prominent on the same frame 12 for the boot of the skater to rest upon and prevent the sole of the boot from interfering with the wheels.
The linearity and uniformity of the frame, along with the particular conformation of the bogies, enable a further advantage to be obtained, which derives from the possibility for the geometry of the above described skate to be most easily varied. In fact, the wheel-carrying bogies 13 can be most clearly noticed (Figure 1) to be able to be mounted on the frame 12 in an opposite direction with respect to the illustrated one, ie. with the wheel journaling axles 15 arranged, with respect to the forward moving direction of the skate (from the right to the left in Figure 1), before (instead of after) the axles 17 used to journal the bogies on the frame.
By varying the geometry of the skate the result is obtained of varying the trim of the skate with respect to the ground. This enables the skater, in particular in the case of tortuous, rough or bumpy roads, to adapt to his/her own requirements the expected response of the skate.
According to the present invention, the system of independent elastic suspension means of the wheels 11 comprises two compression springs 24 (Figures 1 and 3) for each wheel, which are inserted in the frame 12 at the sides of the respective wheel. The springs 24 are arranged with their axis substantially vertical and co-planar with the axis of the axle 15 of the wheel 11.
The springs 24 act between a check 25, attached to the lower surface of the upper flat portion 30 of the frame, and a plane abutment means 26 provided at the lower end portions of the arms 14 of the wheel-carrying bogie 13. In correspondence of said abutment means 26 there is attached a boss 27 adapted to ensure the correct positioning of the extremity of the spring.
From a geometrical point of view, it can be noticed that the abutment 26 provided for each spring on the respective arm 14 of the bogie 13 is located at a level comprised between the level of the axle of the wheel and the level of the upperv extremity of the circumference or rim of the wheel.
The described solution, in which each wheel 11 is journaled on to a bogie 13 which is in turn journaled in the frame 12, and the springs 24 are so provided as to act between the frame and the wheel-carrying bogie, enables, also owing to the particular shape of the bogie 13, the overall height of the skate to be reduced, thereby increasing the compactness of its structure and its stability when rolling.
In an advantageous manner, the springs 24 are provided with screws 28 for setting, ie. adjusting the compression thereof so as to be able to adapt the elastic suspension system of the skate to the characteristics of both the skater and the ground. The screws 28 are preferably of the type that passes through the upper check 25 of the springs, and are arranged with their axis oriented vertically in view of making it easier and more convenient for them to be actuated. By tightening the screws 28, the springs 24 are compressed and the distance between the upper flat portion of the frame 12 and the axles of the wheels 11 is reduced. This practically means a reduction in the amplitude of the floating action of the wheel-carrying bogies 13, within what can be seen as the space defined between the check 25 and the abutment 26. If desired, therefore, also a fully rigid suspension might possibly be obtained. On the other hand, it is fully apparent that, thanks to the independent character of the suspension means, it is possible for the vibration-dampening effect to be adjusted in a different manner for each wheel or group of wheels.
The elastic suspension system according to the invention does away with the need for wheels provided with any considerable rubber-tireing to be used, thereby making it possible for following further advantages to be obtained: a reduction in gyroscopic masses, a reduction in energy losses due to deformations of the rubber-tires of the wheels, a reduction in rolling friction thanks to more rigid wheels.
The roller skate according to the present invention lays itself open to a further, final consideration. In view of the need for it to accomodate the springs 24, the frame 12 has a greater width than the frames of prior-art skates. However, this greater width of the frame 12 is counterbalanced by an extremely reduced height thereof Therefore, when the skater takes a bend, and leans over to a slanting position in order to follow the trajectory, it will always and in any case be the boot that enters into contact with the ground in advance of the frame.

Claims

Roller skate, in particular roller skate with in-line wheels provided with elastic suspension means, comprising a rigid frame (12) on to which there are journaled a plurality of wheels (11) adapted to rotate about respective horizontal axes, each wheel being associated to a pair of vertical-axis compression springs (24) mounted at the sides of the wheel and acting against the frame of the skate, characterized in that each wheel (11) is journaled to the lower end portion of a floating bogie (13) whose upper end portion is hinged on to the frame (12) of the skate (10), and each spring (24) of said pairs of springs is compressed between the frame and the lower end portion of the bogie on to which the respective wheel is journaled..
Roller skate according to claim 1, characterized in that the bogie (13) is formed by two arms (14) whose lower end portions are connected by a horizontal-axis axle (15) arranged orthogonally to the frame (12), on which the respective wheel (11) is mounted rotatably, the axis of the axle (15) being situated at a lower level than the upper extremity of the circumference of the respective wheel.
Roller skate according to claim 1 or 2, characterized in that the abutment (26) of each spring (24) on the respective arm (14) in which the wheel (11) is journaled is situated at a level comprised between the level of the axis of the axle (15) and the level of the upper extremity of the circumference of the wheel.
Roller skate according to any of the preceding claims 1 to 3 characterized in that each spring (24) is provided with means (28) for adjusting the compression thereof.
Roller skate according to any of the preceding claims 1 to 4 characterized in that the frame (12) is made out of a C-shaped profile section whose end portions are bent downwards and are provided with the abutments (26) for the springs (24) to bear against them.
Roller skate according to any of the preceding claims 1 to 5, characterized in that the upper surface (30) of the frame (12) is provided with apertures (21) in an aligned arrangement, each one of them corresponding to a wheel (11), so that the upper extremity of the circumference of each wheel extends upwards beyond the surface of the frame.