GB2330340A

GB2330340A - Saddle for a bicycle

Info

Publication number: GB2330340A
Application number: GB9721915A
Authority: GB
Inventors: John Gerard Ridgway
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-10-17
Filing date: 1997-10-17
Publication date: 1999-04-21
Also published as: GB9721915D0

Abstract

To alleviate a concentration of a cyclist's weight at a horn of a saddle, a saddle comprises two seat portions (62,64) independently and freely rotatable relative to a support member (66,68). As such, the seat portions (62,64) exhibit an independent forward and backward rotational movement due to the pressure applied by the cyclist during each revolution of the pedals on a bicycle or exercise bike. The support member (66,68) includes a lateral spindle assembly (66) on which each seat portion is either rotatable directly or with the interposition of a pair of bearings (78,80). To improve comfort the seat portions may be inclined to the horizontal to produce a substantially V-shaped cross-section. A stop prevents excessive backward rotation of the saddle.

Description

Saddle For A Bicycle The present invention relates in general, to a saddle, and is particularly, but not exclusively, applicable to a bicycle saddle arranged to relieve the discomfort typically associated with riding a bicycle.

Many bicycle saddles have been developed to optimize the riding position of a cyclist. Indeed, saddle designs vary according to the function they must perform, e.g racing saddles are made lightweight and aerodynamic, while saddles for exercise are highly durable and not subject to aerodynamic consideration. More especially, a saddle intended for urban use is typically broad at the rear and tapers to a horn at the front of the saddle, with such a design considered to afford the cyclist greatest comfort and Support Such a saddle would be composed of a moulded substrate or frame that may be covered with a stretched leather or a synthetic membrane or fabric For the comfort of the cyclist, a suspension system (usually in the form of wire springs) may be provided beneath the saddle, while additional comfort may also be afforded by the provision of foam or rubber cushioning between the frame and the cover of the seat. This type of saddle promotes a comparatively upright riding position in the cyclist with the weight of the rider/cyclist principally being evenly distributed across the wider/broadest part of the saddle However, leg movement required for rotation of the chain-set still causes the weight of the cyclist to be re-distributed and nonetheless causes rubbing of a cyclist's crotch and Inner thighs against the horn As will be understood, an up-right riding position causes the entire weight of the cyclist to act almost directly through the crotch and buttocks In the past, urban saddles have also been shaped In an attempt to maximise surface contact and hence to distribute the cyclist's weight As previously described, the saddle of a bicycle Intended for racing Is much more streamlined throughout The rear of the saddle is typically narrow and tapers towards a slender and relatively elongate downward curving horn.

This type of racing saddle promotes a more aerodynamic riding position typified by a bending forward of the cyclist, such that the weight of the cyclist is primarily focused through the crotch of the cyclist onto the horn of the saddle Again, the riding position causes rubbing of the inner thighs that can accentuate discomfort and cause "saddle sores" Although a suspension system is not normally provided, a racing saddle is often cushioned with rubber, foam or a synthetic gel.

Intermediate between the racing saddle and the urban cycling saddle is a saddle normally used for cross-country cycling or "mountain biking" A typical saddle of this type is broader than the racing saddle to ensure the comfort of the cyclist over rough terrain whilst still promoting an effective. principally upright, riding position In summary, the principal problem associated with modern cycling is the discomfort caused to the cyclist by the saddle through pressure on the crotch area and the uneven distribution of weight across the buttock. This problem has been exaggerated by modern bicycle design as a consequence, the handlebars being positioned forward but almost at the same height as the saddle thereby promoting the cyclist to lean forward Furthermore, the problem is compounded by the design of modern saddles through which the majority of a cyclist's body weight is distributed across the front of the saddle, i e. the narrow horn, this results In a high degree of pressure to the crotch of the rider. This Is in stark contrast to the very upright riding position adopted on older bicycles, such as the penny farthing, where the handlebars were positioned much higher and In front of the rider.

It can be appreciated that the above problems caused by riding position and saddle design may be of particular significance to a male cyclist Specifically, when seated on a bicycle saddle, the entire body weight of the male cyclist Is placed on the cavernosal artery that supplies the penis with blood. In this respect, constant pressure on this artery can compress it causing a restriction of blood flow Indeed, research indicates that a narrow racing saddle can reduce blood flow through the cavernosal artery by around 66%, while a broader saddle has a lesser effect (approximately 25% constriction). If the pressure on the cavernosal artery is only short lived it may result only in temporary numbness, but, according to current medical opinion, repeated long distance cycling over many years may result in permanent and complete impotence.

Attempts have been made to re-design the bicycle saddle in order to address this problem One such saddle is the BikoTM saddle (manufactured/supplied by Hobson Associates, Inc ) which comprises two elevated, laterally adjustable seat pads and a lowered horn. The seat pads may be spread to create a saddle of the desired width, while the relative displacement in height is intended to reduce body contact with the horn However, this design of saddle does not eradicate the problem of uneven weight distribution across the buttocks, nor does it totally avoid the painful rubbing contact between the horn and the crotch of the cyclist Accordingly. in first aspect, the present invention provides a saddle comprising a plurality of seat portions each located on a support member, the plurality of seat portions arranged to form the saddle and wherein the plurality of seat portions are Independently and freely rotatable relative to the support member.

In a preferred embodiment, the support member Is a spindle and each of the plurality of seat portions contains a shaft laterally extending through the seat portion, wherein the spindle is arranged to locate within each shaft. The saddle preferably further comprises a plurality of bearing chases located across the spindle, the plurality of seat portions, when positioned on the spindle, being arranged to rest and rotate on the plurality of bearing chases.

Alternatively. at least one of the spindle and each of the shafts is coated with a low friction material, such as polytetrafluoroethylene, or a lubricant is provided between the spindle and a surface of each shaft.

The support member of the saddle Is preferably arranged to be centrally retained within a clamp such that the plurality of seat portions are distributed on either side of the clamp, which clamp can be mountable on a seat stem arranged to locate within a bike frame.

The plurality of seat portions optionally each have a distributed weight profile arranged to tilt the saddle in forward orientation. The saddle may further comprise a back stop, e g a stop bar or a spring, arranged to prevent rotation in a backward direction or beyond a predetermined angle, e g. approximately about the horizontal The saddle of the present Invention is suitable for use with a bicycle or an exercise bike The present invention therefore advantageously provides an Improved saddle that continuously swivels in a rocking forward-backward motion to ensure that a cyclist's weight Is evenly distributed over the saddle More especially, by providing independent movement for each support cup of the two-piece saddle, the present invention beneficially alleviates a concentration of pressure in both the cavernosal artery and the buttocks during each downward stroke of the pedals (since each support cup remains substantially in total contact with each buttock of the cyclist) Exemplary embodiments of the present Invention will now be described with reference to the accompanying drawing in which FIG. 1 indicates a normal body position of a cyclist during bicycle riding; FIG 2 shows, In perspective, a three-piece split saddle of the prior art, FIG. 3 Is a side view of the prior art saddle of FIG 2, FIG 4 shows, in cross-section, a saddle of a preferred embodiment of the present invention; FIG. 5 shows a suitable clamp mechanism for attaching the saddle of FIG. 4 to a bicycle frame; FIG. 6 shows, in cross-section, a saddle of the present Invention; FIG 7 shows, in perspective, one seat portion of the saddle of FIG. 4, FIG. 8 shows a basic construction of the saddle of FIG 4 in perspective.

Before describing a preferred embodiment of the present invention in detail, a more elaborate discussion of the saddles and riding position of the prior art will be undertaken in order that the addressee can appreciate the significance and differences of the saddle of the present Invention Referring to FIG. 1, a body position of a cyclist is shown in relation to a racing bike 10 having a frame 12, handlebars 14 and a saddle (obscured under a thigh 16 of a cyclist 18) A cross-bar 20, positioned substantially parallel to the ground in the case of a man's bike, extends between the handlebars 14 and a seat pin 22 onto which the saddle is securely mounted The cross-bar 20 has a length commensurate with the length of the upper torso of the cyclist 18 and, as such, causes the cyclist, when seated, to lean forward to grip the handlebars 14 Consequently, the entire weight of the cyclist 18 acts through the saddle and, more especially, is concentrated towards a horn of the saddle, this is shown by acting weight line 24 FIG 2 shows a three-piece, split saddle 30 of the prior art Unlike more conventional saddles of unitary. flared and convex construction, the threepiece saddle 30 comprises two laterally separable shoulders 32-34 that splay horizontally relative to a central channel 36 In this way, the separable shoulders allow the width of the three-piece. split saddle to be varied The separable shoulders 32-34 generally exhibit a convex upper surface and have a tapering configuration from a relatively broad rear-end 40 to a relatively narrow front-end 42. In fact, the front-end can be generally considered to be of truncated triangular configuration. Like most conventional saddles, the two-piece fixed saddle is securely attached to a seat stem 38 that locates with the frame of the bike, with the entire saddle capable of being fixedly inclined relative to the horizontal A horn section 44 representing a third piece of the three-piece split saddle, extends from beneath the separable shoulders 32-34, which horn section 44 dips markedly to the horizontal The separable shoulders 32-34 and the horn section 44 together produce a cut-away concave side profile against which the Inner thigh of the cyclist rests but rubs.

Briefly looking to FIG 31 a side elevational view of the three-piece saddles of FIG. 2 is shown As can be seen, the horn-section 44 can be seen to dip relative to the horizontal, while a ledge 46 Is produced by the extension of the horn section 44 from the laterally separable shoulders 32-34.

Turning now to FIG 4 there is shown a cross-sectional view of a saddle 60 of a preferred embodiment of the present invention The saddle 60 comprises a plurality (and preferably two) independent seat portions 62-64, a horizontal spindle assembly 66 and an elongate central support column 68.

The seat portions 62-64 are generally shaped and dimensioned to comfortably accommodate the buttocks of a cyclist, as will be appreciated In the preferred embodiment, the seat portions 62-64 are made of moulded plastic, but in other embodiments of the invention the seat portions 62-64 may be made of at least one of a gel, a moulded plastic, natural or synthetic rubber, foam or a stretched leather (and combinations thereof).

Moreover, in the preferred embodiment each of the seat portions 62-64 has a substantially horizontal face surface 69, although other embodiments of the invention may have seat portions 62-64 whose face surfaces are Inclined to a horizontal to produce a saddle which is substantially V-shaped in crosssection In such other embodiments, the angle of inclination of each of the seat portions 62-64 to the horizontal is up to 15q, and preferably in the range of 3O 5c Each of the seat portions 62-64 is traversed from side to side by a substantially horizontal cylindrical shaft 70 that is of sufficient diameter to accommodate the horizontal spindle assembly 66. The horizontal spindle assembly 66 is typically of a length commensurate with the combined length realised by the adjacent alignment of the seat portions 62-64, and its midpoint 76 has a restricted diameter The two seat portions 62-64 are therefore freely and rotatably mounted about the spindle assembly 66 ostensibly along their entire length The free rotational movement is illustrated by arrows 77 The elongate central support column 68 has at one end a clamp 72 such as a C-shaped clamp of similar construction to that of a conventional handlebar stem clamp assembly, capable of being tightened around the horizontal spindle assembly 66 by a screw (or similar) 73, this Is shown in FIG 5 A far end 67 of the elongate central support column 68 Is capable of being engaged securely In the bicycle frame in accordance with known and conventional techniques The clamp 72 is arranged to clasp securely the mid point 76 of the spindle assembly 66, with this illustrated In FIG 4. A head 71 of the clamp 72 lies In a channel 75 between the adjacently positioned seat portions.

Free rotational movement of the seat portions 62-64 about an axis of the spindle assembly 66 Is facilitated, in the preferred embodiment of the present Invention, by two pairs of bearing chases 78-80 positioned between the seat portions 62-64 and the horizontal spindle assembly 66 More explicitly, in the preferred embodiment the bearing chases 78-80 are typically located in guide channels 82 that retain the bearing chases 78-80 The guide channels 82 can be located on the spindle assembly 66 or within an inner surface of the shaft 70 of the seat portions 62-64 (or both). Indeed, the bearing chases 7880 may be permanently retained within either the seat portions or the spindle assembly 66, but this is less preferable from the provision of easily removable bearing chases because the bearing chases may need to be replaced with wear Consequently, when positioned on the spindle assembly 66 the seat portions 62-64 rest and rotate on the bearing chases 78-80.

In the preferred embodiment, the seat portions 62-64 are securely retained on the horizontal spindle assembly 66 by means of a broad headed pin 84 driven into each end of the spindle assembly 66 The diameter of a head of the pin 84 is larger than the diameter of the shafts in the seat portions 62-64, thereby preventing the seat portions 62-64 from sliding from the spindle An alternative fixing method may involve a pin being located through an extending portion of the spindle assembly 66, as will readily be appreciated.

Preferably the seat portions have shoulders 86 that extend over the clamp 72 of the central support column 68. The shoulders 86 thereby cover channel 75 between the seat portions 62-64 whilst allowing rotation of the seat portions 62-64 over the top of the clamp 72.

The entire arrangement attaches to a bicycle or exercise bike via the central support column 68 whose far end 67 resembles a conventional saddle stem fitting When the saddle of the present Invention Is securely mounted in a bicycle frame. the horizontal spindle assembly 66 is positioned parallel to a crankshaft of the pedals The plurality of seat portions 62-64, therefore Independently rock (i e., rotate) backwards and forwards with each stroke of the pedals Therefore when a cyclist Is seated on the saddle of the present invention, the weight of the cyclist is substantially equally divided across the whole of each buttock during the entire pedaling motion because each of the seat portions 62-64 of the saddle Independently moves In accordance with the movement of the cyclist's legs More particularly, when the leg of the cyclist pushes down on the pedal, the downward pressure of the thigh on the front of the seat portion supporting this leg causes the seat portion to rotate forwards about the spindle assembly 66, thereby advantageously maintaining full contact between the bottom of the cyclist and the seat portion.

Conversely, as the pedal rotates around the chain set and the leg is in upward motion, the displacement of the thigh causes the seat portion supporting this leg to rotate backwards about the spindle assembly 66. It can be appreciated that, during normal cycling, the two seat portions 62-64 of the preferred embodiment alternately and oppositely rotate towards the front of the bicycle and then return towards their original position Referring now to FIG 6, an alternative embodiment of the present invention is shown. The general structural configuration of this alternative embodiment is similar to that of FIG 4, and so common features share the common numbering scheme In this alternative embodiment FIG 6 also illustrates the provision of stop bars or a spring mechanism 94 (referred to as a back-stop) located on the central support column 68 and set towards the back of the saddle The stop bars or spring 94 engage the saddle 90 during the backward motion of each seat portion and thereby prevent the saddle form rotating too far backwards Additionally to assist a cyclist in mounting the saddle, each seat portion has a distributed weight profile, such that the saddle Is encouraged. at rest. to have a forwardly inclined orientation relative to the horizontal.

Briefly turning to FIG s 7 and 8, a basic structure for a seat portion and a perspective view of an assembled saddle are shown In FIG 7, the seat portion Is generally seen to be of rectangular shape, with the shaft 70 and the shoulders 86 shown It will, of course, be appreciated that the above description has been given by way of example only, and that modifications in detail may be made within the scope of the present invention For example, the shape of the seat portion (shown in FIG 7) may be altered by having cut-away corner sections Also, while the spindle assembly 66 has been described as being horizontal, the spindle could be inclined to produce a slightly V-shaped saddle that therefore eliminates the requirement for the inclination In the seat portions, as previously described Furthermore, the shaft could be realised in a two part assembly.

Claims

CLAIMS 1 A saddle comprising a plurality of seat portions each located on a support member, the plurality of seat portions arranged to form the saddle and wherein the plurality of seat portions are independently and freely rotatable relative to the support member.
2 The saddle according to claim 1, wherein the support member is a spindle and each of the plurality of seat portions contains a shaft laterally extending through the seat portion, wherein the spindle is arranged to locate within each shaft
3. The saddle according to claim 2, further comprising a plurality of bearing chases located across the spindle, the plurality of seat portions, when positioned on the spindle, being arranged to rest and rotate on the plurality of bearing chases.
4. The saddle according to claim 3, wherein the bearing chases are located with guide channels in a surface of the spindle
5. The saddle according to claim 2 or 3, further comprising a plurality of bearing chases located within the plurality of seat portions such that, when positioned on the spindle, the plurality of seat portions are arranged to rest and rotate on the plurality of bearing chases
6 The saddle according to claim 2, wherein at least one of the spindle and each of the shafts is coated with a low friction material
7 The saddle according to claim 6, wherein the low friction material is polytetrafluoroethylene
8 The saddle according to claim 2, wherein a lubricant is provided between the spindle and a surface of each shaft.
9. The saddle according to any preceding claim, wherein the support member is arranged to be centrally retained within a clamp such that the plurality of seat portions are distributed on either side of the clamp.
10. The saddle according to claim 9, wherein the plurality of seat portions are separated by a central channel located above the clamp and wherein the plurality of seat portions further comprise shoulders that extend across the central channel.
11 The saddle according to any preceding claim, wherein each of the plurality of seat portions is inclined to a horizontal to produce, when assembled, a substantially v-shaped cross-section.
12 The saddle according to claim 11, wherein an angle of inclination of each of the plurality of seat portions to the horizontal is up to approximately fifteen degrees, and preferably In the range of three degrees to five degrees
13. The saddle according to any preceding claim, wherein the plurality of seat portions each have a distributed weight profile arranged to tilt the saddle in a forward orientation
14. The saddle according to any preceding claim, further comprising a back-stop arranged to prevent rotation of the saddle in a backward direction and beyond a predetermined angle.
15 The saddle according to claim 14, wherein the back-stop is a stop bar.
16. The saddle according to claim 15 wherein the back-stop is a spring
17 The saddle according to claim 1415 or 16. wherein the predetermined angle is substantially horizontal
18. The saddle according to any preceding claim, wherein each of the plurality of seat portions has an indentation in its surface shaped to substantially correspond to a shape of a buttock of a cyclist
1 9. The saddle according to any preceding claim, further comprising stop means arranged to retain the plurality of seat portions on the support member.
20. The saddle according to claim 19, wherein the stop means is a broad headed pin, the head of the pin being larger in diameter than the shafts of the seat portions
21 The saddle according to any preceding claim, wherein the saddle is for a bicycle.
22 The saddle according to any one of claims 1 to 20, wherein the saddle is for an exercise bike.
23 The saddle according to any preceding claim, wherein the saddle comprises two seat portions each seat portion arranged, in use, to support at least a portion of a buttock of a cyclist
24. The saddle according to any preceding claim, wherein the plurality of seat portions are made of at least one of a gel, a moulded plastic and a stretched leather.
25. A bicycle comprising a saddle according to any one of claims 1 to 24
26. A saddle comprising a plurality of independently rotatable seat portions substantially as hereinbefore described with reference to FIGs. 4, 5 and 6 of the accompanying drawings.