GB2268454A - Adjustable bicycle saddle - Google Patents

Abstract

A bicycle saddle has a leather top and a metal frame, the top extending in known manner from a frontal metal nose piece to a rear metal cantle, the leather being rivetted to the nose piece and to the cantle. Fixed at the front ends of a pair of rods which extend rearwardly to adjoin the cantle, is an internally threaded sleeve, there being a bolt passing through said sleeve, in threaded engagement therewith. The bolt has at its forward end a head bearing against the nose piece, the bolt head being domed and having a socket with hexagonal walls which may be engaged with a hexagon key. The nose piece has an aperture to allow passage for such a key and hence access for adjustment from the front of the nose piece.

Description

BICYCLE SADDLE This invention relates to saddles for pedal bicycles and in particular to a saddle in which, in addition to a metal frame comprising a nose piece spaced by rods from a rear cantle plate, there is a top of leather or the like flexible or stretchable material, there being also means for adjusting the distance between the nose piece and the cantle plate and so adjusting the tensioning of the top.

Conventionally, the nose of a leather saddle top is rivetted to a shaped nose piece and the head of the screw bolt of a nut and bolt adjusting mechanism bears against this nose piece, tensioning being achieved by rotating a nut on the threaded stem of the bolt, said nut reacting against a bracket which is secured to the saddle frame.

The tensioning nut is usually located within the nosepiece and is heavily shrouded thereby, and there is in general a shortage of space available around the nut within the nose piece which latter is a closed metal body open only at its bottom. This renders access to the nut using a spanner for purposes of adjustment, extremely difficult. Even when the spanner is engaged with the nut, it is difficult to turn the nut more than a few degrees before the flanges of the spanner foul the internal walls of the nose piece.

The present invention has for its object to provide a lightweight adjustable leather saddle which has few parts and yet which has adequate structural strength and stability. And the invention has as its principal object to provide for easy, reliable and readily accessible adjustment of the tensioning of such a saddle while again the number of components employed are kept to a minimum.

According to this invention there is provided a bicycle saddle with a leather top and a metal frame, the top extending in known manner from a frontal metal nose piece to a rear metal cantle, the leather being rivetted to the nose piece and to the cantle, and there being rigidly fixed at the front ends of a pair of rods which extend rearwardly to adjoin the cantle, an internally threaded hollow sleeve, and including a bolt passing through said sleeve, in threaded engagement therewith, and said bolt having at its forward end a head bearing against the nose piece, said bolt head being domed and having a socket with hexagonal walls which may be engaged with a hexagon key, the nose piece having an aperture to allow passage for such a key and hence access for adjustment from the front of the nose piece.Preferably, the nose piece has internally, a cup and the head of the tensioning bolt is seated in this cup, the cup being apertured to provide the aforementioned key access.

Preferably said hollow sleeve is so fixed at the front ends of said frame rods, that, when extended, the axis of the sleeve intersects the cantle. In this way when the bolt is turned to tension the leather saddle top, the tensioning force then exerted is directly aligned with the cantle. The sleeve, the frame rods and the cantle are joined together in a structure which is sufficiently rigid that any forces which tend to rotate or skew the nose piece whether about a vertical or a horizontal axis are adequately resisted.

However the nose piece is required to move fore and aft relative to the threaded sleeve as the tensioning bolt is rotated to adjust the tensioning of the leather saddle top and preferably there is provided a transverse bearing bar which is fixed transversely of the saddle immediately below said sleeve and is rigidly secured thereto and to the front ends of the two frame rods, and the nose piece has two side flanges, one on each side of the sleeve, said side flanges having straight lower flank edges which when the nose piece moves fore-and-aft in adjustment, slide on said bearing bar. The bearing bar resists torsional forces which tend to cause the nose piece to rotate about a longitudinal axis with respect to the cantle.

The cantle can conveniently be formed of tubing, which is shaped to fit the rear end of the leather top, the tubing being drilled transversely to accommodate rivets by which the top is secured to it, and to provide holes to receive the rear ends of the frame rods which are secured to the cantle and which preferably are also formed from tube.

The invention will now be described with reference to the accompanying drawings in which: Figure 1 is a side view, partly in cross-section of an adjustable frame for a leather saddle according to this invention; Figure 2 is a plan view of part of the frame; Figure 3 is an end view from the front taken in the direction of the arrow III in Figure 2; Figures 4 and 5 illustrate a nose piece, Figure 4 being a view in cross-section taken on the line IV-IV of Figure 5 and Figure 5 being a view in cross-section taken on the line V-V of Figure 4; Figures 6 and 7 are exploded schematic side views, Figure 6 being of a saddle according to the present invention and Figure 7 being of one known conventional adjustable leather topped saddle.

In the conventional leather saddle, as is shown in Figure 7 of the accompanying drawings, the leather saddle top T is pre-formed and shaped. This is rivetted at the rear to a metal cantle CP, and at the front to a nose piece NP. Extending forwardly from the cantle are a pair of frame rods F composed of shaped steel wire of about 1/4" diameter. It is often the case with known frames that the front ends. of the frame rods F are joined together in a loop which passes through a tensioning device generally designated S. This essentially comprises a bolt and a nut, the latter being accessed for spanner adjustment from underneath the nose of the saddle, but inconveniently because of the closed shape of the nose piece which is open for spanner access only at its bottom. The frame-work with its tensioning device as described represents conventional practice.

If, in this type of frame there is articulation about a transverse axis at the loop at the front end of the frame F, then, following stretching of the leather and due to the opposing forces W and w caused by the riders weight, the axis A of the tensioning bolt may be shifted so that it lies substantially below a notional line leading directly towards the cantle, with the nose tending to skew over. This does not affect the functioning of the saddle, but gives used leather saddles a mis-shapen appearance at the front. This is not to be confused with the desirable moulding of the shape to fit the rider's individual form of ischial pressure points.

Another consequence is that when the saddle is tensioned, the offset of the line of action (in the vertical plane) of the tensioning nut and bolt compared with the line of action of the leather when stretched, causes an increase in the bending moment in the frame rods which mitigates against an efficient frame construction from a weight saving point of view. Also the heavy loading exerted when the saddle leather is placed under tension tend to cause skewing about a vertical axis. Thus, in order to overcome this, adjustable leather saddles are often of rigid multi-component construction and are heavy in comparison with moulded plastic ones in which there is no need for tensioning adjustment.

Referring now to the embodiment of the present invention depicted in Figures 1 to 6, the leather saddle top T extends in known manner from a frontal metal nose piece 11 to a rear metal cantle 12, the leather being rivetted to the nose piece and to the cantle, and there being an internally threaded hollow sleeve 14 rigidly fixed at the front ends of a pair of rods 13 which extend rearwardly to adjoin the cantle 12. A bolt 21 passes through the sleeve 14, in threaded engagement therewith, and at its forward end the bolt 21 has a head 22 bearing against the nose piece 11. The bolt head 22 is domed and has a socket with hexagonal walls such as may be engaged with a hexagonal Allen key (not shown). The nose piece 11 has an aperture 15 to allow passage for such a key.Preferably, the nose piece 11 has internally, a cup 23 and the head 22 of the tensioning bolt 21 is seated in this cup, the cup being apertured at 15 to provide the aforementioned key access.

The hollow sleeve 14 is so fixed at the front ends of the frame rods 13, that, when extended, the axis of the sleeve intersects the cantle 12. In this way when the bolt 21 is turned to tension the leather saddle top, the tensioning force then exerted is directly aligned with the cantle. The sleeve 14, the frame rods 13 and the cantle 12 are joined together by brazing or welding in a structure which is sufficiently rigid that any forces which tend to rotate or skew the nose piece 11 whether about a vertical or a horizontal axis are adequately resisted.

However the nose piece 11 is required to move fore and aft relative to the threaded sleeve 14 as the tensioning bolt 21 is rotated to adjust the tensioning of the leather saddle top and accordingly, there is provided a transverse bearing bar or tube 16 which is fixed transversely of the saddle immediately below the sleeve 14 and is rigidly secured by brazing or welding to the sleeve and to the front ends of the two frame rods 13. The nose piece 11 has two side flanges, one on each side of the sleeve, said side flanges having straight lower flanks or edges which when the nose piece moves fore-and-aft in adjustment, slide on said bearing bar. The bearing bar 16 resists torsional forces which tend to cause the nose piece 11 to rotate about a longitudinal axis with respect to the cantle.

The cantle 12 can conveniently be formed of tubing, which is shaped to fit the rear end of the leather top, the tubing being drilled transversely to accommodate rivets by which the top is secured to it, and to provide holes to receive the rear ends of the frame rods which are secured to the cantle and which are also preferably formed from tube.

This example of the invention shown in Figures 1 to 6 of the accompanying drawings, has principal features which are:- 1. The focus 10 (Figure 6) of the bolt 21 and nut 14 tensioner device is towards the cantle 12 to which the rear end of a leather saddle top is rivetted.

2. The rods 13 of the frame, which are preferably tubular to save weight, lead to an apex at the front at which the nut like sleeve 14 of the tensioning device is rigidly fastened by welding or brazing.

This provides resistance to any tendancy for the nosepiece to skew.

3. The rods 13 are welded or brazed to the cantle 12 which is preferably made of bent tube, the tube being drilled transversely, to receive the rods and to give access for rivetting.

4. The bolt 21 of the tensioning device has an 'Allen' screw recessed head 22 which is of spherical form and bears in the cup 23 to self-align the metal nose-piece 15, to which the front end of the leather saddle top is rivetted. The head 22 with its hexagonal recess is readily accessible by Allen key for adjustment purposes from the front of the nose piece.

5. The vertical loading from the leather top to the front of the frame is transmitted by the transverse bearing 16, which also provides resistance to rotation or skewing of the nosepiece 15 which slides upon it when the tensioning device is operated to stretch the leather.

The bolt 21 can be given a left hand (L.H.) thread to give conventional R.H. rotation for tightening.

The frame structure from the nose to cantle is essentially stable under the compression loading as it reacts to tensioning the leather top. So the tensioned top remains symmetrical and avoids skewing.

A leather saddle with a frame and with tensioning means constructed and arranged as set out above, releases the potential inherent in the "hammock" form of stretched leather top, for providing some vibration isolation.

Measurements show a significant vertical flexibility of 3501b/in; and yet this is highly damped. These springing properties should not be compared with sprung saddle frames which allow rocking of the pelvis when pedalling, nor with the soft tops of rigid plastic saddles, which can interfere with the rider control function.

As an example a leather saddle using a frame has been constructed from steel tubing in the manner described and has been found to be fully competitive in weight, at 270 grams., with a plastic saddle. The new saddle has been proved to have good fatigue strength.

Claims (6)

1. A bicycle saddle with a leather top and a metal frame, the top extending in known manner from a frontal metal nose piece to a rear metal cantle, the leather being rivetted to the nose piece and to the cantle, and there being fixed at the front ends of a pair of rods which extend rearwardly to adjoin the cantle, an internally threaded sleeve, and including a bolt passing through said sleeve, in threaded engagement therewith, and said bolt having at its forward end a head bearing against the nose piece, said bolt head being domed and having a socket with hexagonal walls which may be engaged with a hexagon key, the nose piece having an aperture to allow passage for such a key and hence access for adjustment from the front of the nose piece.

2. A saddle according to claim 1, wherein the nose piece has internally, a cup in which the head of the tensioning bolt is seated.

3. A saddle according to claim 1, or claim 2 wherein said sleeve is so fixed at the front ends of said frame rods that, when extended, the axis of the sleeve intersects the cantle.

4. A saddle according to any one of claims 1 to 3 wherein a bearing bar is rigidly fixed transversely of the saddle immediately below the hollow threaded sleeve, and is secured thereto and to the front ends of the two frame rods, and wherein the nose piece has two side flanges, one on each side of the sleeve, said side flanges having straight lower flank edges which when the nose piece moves fore-and-aft in adjustment, slide on said bearing bar.

5. A saddle according to any one of claims 1 to 4 and wherein said frame rods and said cantle are made from tube.

6. A saddle for a bicycle substantially as hereinbefore described with reference to Figures 1 to 6 of the accompanying drawings.