GB2171369A

GB2171369A - Pivot mounted cycle seat with spring cradle

Info

Publication number: GB2171369A
Application number: GB08504692A
Authority: GB
Inventors: Stephen Allen Holcomb; John E Aker
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-02-22
Filing date: 1985-02-22
Publication date: 1986-08-28
Also published as: GB8504692D0; GB2171369B

Abstract

A cycle seat 11A is fixed to a conventional seat post by means of a seat post clamp 29. The base 71 of the seat is pivotally mounted on a spring cradle 28 which is secured to the seat post clamp 29. The cradle 28 extends rearwardly from the seat post to support the bottom of a spring 47 which bears against the underside of the seat base 71, urging the seat base 71 to abut stops 69A mounted on the spring cradle 28 forward of the pivot 31. The longitudinal position of the seat 11A may be adjusted by locating the seat 11A at a selection of pivot points along the seat base 71. A rigid shell 79 is fixed to the underside of the seat base 71 to strengthen the overall structure. <IMAGE>

Description

SPECIFICATION Pivot mounted cycle seat with spring cradle The present invention relates to seats for manual or power cycles and more particularly to seats with thrust backs mounted on vertical seat posts of a cycle. The field of the invention is exemplified by previous patents to inventor Holcomb U.S 3,970,345 issued 20 July 1976 and U.S. 4,141,587 issued 27 February 1979. Each of these cited patents is concerned with cycle seats with upturned seat backs for added thrust for pedalists and added comfort for power cyclists, but each shows contoured seat perimeters to eliminate chafing and provide adequate buttock support.

The object of the present invention is to provide a seat and seat mount that not only provides comfort and thrust efficiency, but also supplies a degree of sprung comfort and adjustability for comfort unattained in prior art devices of this nature, without interference with the attachment of cargo carrying apparatus. The present invention is capable of fore and aft adjustment to suit long or short legged riders and allows full use of the vertical adjustment inherent in the conventional seat mounting post of bicycles, mopeds and other light-powered cycles.

The added comfort does not impair performance and the enjoyment of cycling and does not encourage bad riding habits.

Thus according to the present invention there is provided a seat for mounting on a cycle seat post by means of a seat post clamp, including a seat base from which are suspended two rails spaced transversely across the seat base, a spring cradle, mounted on the seat post clamp, and a pivot bolt which extends through a set of transversely aligned holes in the rails and spring cradle pivotally mounting the seat base on the spring cradle in a selected position within a range of longitudinal positions, the spring cradle extending rearwardlyfrom the pivot to support a spring acting between the spring cradle and the underside of the seat base, thus urging the seat base to abut stops fixed to the cradle forward of the pivot.

Several of the conventional seat post clamps are adapted for use with the apparatus of the invention, but the presently preferred clamp is one made to clamp two different post diameters, a clamp that may be turned about its clamping bolt to change the fore and aft location of the larger and smaller clamping loop respectively and vice versa. The spring may be changed to alter the spring load to suit the rider's weight or technique and the seat accommodates to any cycle with an upwardly extending mounting post.

Some embodiments of the present invention will now be described, by way of example, with refer ence to the accompanying drawings, in which: Figure 1 is a left side elevational view of a cycle seat in accordance with the invention; Figure 2 is a transverse sectional elevational view taken along line 2-2 of Figure 1; Figure 3 is a top plan view of the spring cradle with the position of the spring shown therein; Figure 4 is a fragmentary left side elevational view of the apparatus of Figure 1 in an alternate mounting arrangement; Figure 5 is a left side elevational view of an alternate embodiment of the invention; Figure 6 is a longitudinal sectional elevational view of the embodiment of Figure 5; Figure 7 is a rear elevtional view of the embodiment of Figure 5; and Figure 8 is a bottom plan view of the embodiment of Figure 5.

In the embodiment in Figures 1 to 4 a seat 11 in accordance with the invention has a seat base 12 from which a seat back 14 rises and bottom side rails 16 and 17 are suspended. A seat pad 18 is adhered to the upper surface 12A of the seat base and upper surface 1 4A of the seat back. The back is concave where it meets the pad and of substantially uniform thickness so that a convex portion 14B is apparent in Figure 1.The bottom side rails 16,17 extend rearwardly to an aft end 21 which extends upwardly to fair into the convex area 148 of the back 14. As can be seen from Figure 2, the rails 16 and 17 are transversely spaced about the centre of the seat base 12, inboard of the outer edges 23, 24 thereof.The seat pad 18 is substantially the same in perimetral configuration as the seat base and back, and may be of any suitable resilient material such as foam plastic or rubber. Ideally, any such material will have an outer skin to resist sun and water.

Again referring to Figure 1, an elongate aperture or slot 26 in each of the side rails provides means for attaching a spring cradle 28 and a conventional seat post clamp 29 to the seat itself. Attachment is by means of a pivot bolt 31 which, in Figure 1,extends through a forward aperture 32 of each rail visible in Figure 4. The aperture and bolt position of Figure 1 represents an extreme rearward positioning of the seat 11 with respect to a conventional seat post 35 of a cycle 36 whose upper frame member 37 and post socket 38 are all shown in broken lines in Figures 1 and 4.

As is apparent from Figure 8, which is a bottom plan of an alternative but similar embodiment, the seat base tapers to a narrow front 41 in both the embodiments of Figure 5 and Figure 1. The seat base is broad nearthe rise ofthe back 14to provide full support for the buttocks of the rider, but, because of the tapered configuration, gives clearance for the inner thigh to move past the seat base edge in the pumping motion associated with cycling. The broadest points of the seat base 12 are indicated at 23 and 24 in Figure 2, while the narrow front portion is shown at 41 in Figures 1 and 4 of the first embodiment. The seat base tapers from a diagonally vertical line 45 toward the narrow front 41, the line 45 indicates the forward portion of the side rails 16, 17.The depth of the rails below the bottom surface 46 of the seat base depends in part on the seat material and whether or not a metal shell, such as the shell 62 of the embodiment of Figure 5, is used with a plastics moulded seat. The strength of the material, of course, determines how thick the rail must be below the aperture 32 and the elongate aperture 26 to give sufficient strength to resist the strain imposed by riders of varying weights and the rocking movement of the seat against the spring bias of a compression spring 47.

Spring cradle 28 is shown in plan in Figure 3 wherein the cradle 28 is seen to have side bars 51 and 52 transversely spaced and depending aft in a cup side 53 on each bar. Transverse end wall 54 connects the cup sides as does an intermediate wall 55. Together with a floor 56 they define a spring cup 57 in which the lower end of compression spring 47 seats. The upper end of the spring has a wear pad 58 of cylindrical shape, which fits into the top turn of the spring and is a buffer between the hard end of the spring and the under side of the seat base 12. The pad is best seen in the sectional elevation of Figure 6, the use of the pad being the same in both embodiments. The pad is usually of Teflon or may be another non-abrasive material well known in the art.

Side bars 51, 52 of the spring cradle extend forwardly from the cup to a pair of longitudinally spaced apertures, one of which apertures, 59, is seen in Figures 1 and 4. Clamping bolt 61 is located in the other, more foward aperture pair, in those Figures, but may be located in aperture 59 to change the fore to aft position of the seat with respect to the seat post, as desired by the rider.

Clamp 29 is a conventional bicycle seat post clamp such as that made by the Faulhaber Division of Persons-Majestic Manufacturing Company and is a standard double loop clamp to accommodate to either of the common post diameters for bicycles.

The clamp, as seen in Figure 8, has two loops 29A, 29B, the loop 29B being the larger, it being fixed to the seat post 35 in the embodiments of Figure 1 and Figure 5. By loosening the nut on bolt 61 the clamp loop may be rotated about the bolt and thus reverse the relationship of the desired loop with respect to the seat post to change the fore to aft position of the seat with respect to the post. The conventional ratchet or friction grip elements shown generally at 65 provide for adjusting the tilt of the seat with respect to the upper frame member 37 of the cycle as desired.

The spring cradle has forward limbs 67 and 68 with feet 69, 69A, respectively, integrally formed with side bars 51, 52. The limbs and feet act to establish the relationship of the seat to the cradle by contact of the feet against the underside 46 of the seat base to limit the tilt of the seat about the pivot bolt 31 when the weight on the seat moves the narrow end 41 towards the upper frame member 37.

Since the pivot bolt passes through the cradle limbs 67,68 by way of limb apertures 70 and the feet contact the seat base bottom forward of the pivot bolt, the forward tilt of the seat is thereby controlled by the limb extension above the pivot bolt. The backward tilt of the seat, which gives the cushioning effect to the seat, is against the spring load of compression spring 47 and the degree or angle "A" of tilt is dependent upon the force applied by the rider's weight, either as a result of pedalling motion or from displacement of the weight due to a rough travel surface acting upon the compression spring.

The spring may be changed as ride conditions change, both stiffer and "softer" springs being readily available.

In order to preclude transverse displacement of the cradle with respect to the center of the seat base, pivot bolt 31 has tubular spacers 31 A, B, placed between the side rails and the cradle side bars 51, 52.

With the seat post clamp secured to the seat post and the spring cradle secured to the seat post clamp, the orientation between the seat post and the seat is determined by the particular aperture in which the pivot bolt 31 resides. In Figure 1 the pivot bolt resides in the forward rail aperture 32, but in Figure 4 the pivot bolt 31 resides in the elongate aperture 26.

The relative position of the seat 11 is further forward with respect to post 35 in Figure 1 than it is in Figure 4 and, as is evident from Figure 4, the seat is capable of further forward adjustment determined by the length of the aperture.

As mentioned before, further adjustment can be accomplished by rotation of the Faulhabertype post clamp about the clamping bolt or by moving the clamping bolt aft to aperture 59 of cradle bars 51 r 52.

Each of these adjustments is easily made with basic tools common to cyclists and the seat of the invention may thus be fitted to the particular desires of any rider.

The advantages recited for the embodiment of Figure 1 are also applicable to the embodiment of Figure 5, the principal distinctiveness of the Figure 5 embodiment residing in the protective shell 62 which enables the seat 1 1A to be of a moulded plastics material. Seat base 71 and seat back 72 are integrally moulded and receive a seat pad 73 in the same configuration as described with respect to the embodiment of Figure 1. Seat 1 1A also has transversely spaced parallel side rails 16 and 17, as can be seen in Figures 5 to 8.Shell 62 is seen to have U-shaped transverse configuration in Figure 7 where it resides between the side rails 16, 17 and is held in contact with the bottom side 46A of the seat base 71 by a pair of bolts 74 through each side rail and the pivot bolt 31, which passes not only through the apertures of the side rails 16 and 17, but also through the depending side walls 76,77, of the metallic shell 62. The pivot bolt also passes through the forward apertures 70 of the spring cradle limbs 67,68, such that the cradle feet 69, 69A, register in contact with the under surface 79 of the shell 62 in the same way that the cradle feet registered against the under surface 46 of the seat base 12 of the embodiment of Figure 1. The upper pad 58 of the compression spring 47 is forced by the spring against the bottom surface 79 of shell 62, and the spring bias is thus transmitted from the floor 56 of the cradle cup 57 in the same manner as in the embodiment of Figure 1.

Shell bolts 74 at the back of the seat 1 1A may be used to mount cargo apparatus to the seat through the aperture in the seat rails through which the bolts 74 pass. Similarly, the seat 11 of Figure 1 can be provided with similar rear apertures for the same purpose. Also, while not shown in the embodiment of Figure 5, slots or elongate apertures like aperture 26 of Figure 1 may be placed in the Figure 5 embodimentforthe purposes set forth with respect to the Figure 1 embodiment.

While several embodiments have been shown or described in the foregoing specification and accompanying drawings, it is to be understood that the specification and drawing are illustrative only, the invention being defined by the claims, since other variations than those disclosed herein may occur to the persons skilled in this art within the scope of the

Claims

claims. CLAIMS

1. A seat for mounting on a cycle seat post by means of a seat post clamp, including a seat base from which are suspended two rails spaced transversely across the seat base, a spring cradle, mounted on the seat post clamp, and a pivot bolt which extends through a set of transversely aligned holes in the rails and spring cradle pivotally mounting the seat base on the spring cradle in a selected position within a range of longitudinal positions, the spring cradle extending rearwardly from the pivot to support a spring acting between the spring cradle and the underside of the seat base, thus urging the seat base to abut stops fixed to the cradle forward of the pivot.

2. A seat as claimed in claim 1, wherein a shell, fixed to the underside of the seat base, extends between the inner faces of the rails, having holes aligned with those in the rails.

3. A seat as claimed in claim 1 or 2, wherein the cradle comprises side bars flanking the seat post which support the stops and a spring cup which supports the spring, the side bars being formed with holes to receive the pivot bolt and the stops having feet to register with the underside of the seat base.

4. A seat as claimed in claim 3, wherein the side bars have transversely aligned holes between the stops and the spring cup to receive a seat post clamping bolt.

5. A seat substantially as described with reference to the accompanying drawings.

6. In a cycle seat for conventional cycles with upwardly protruding seat attachment posts and conventional seat post clamps having a securing bolt the combination comprising a seat base, a seat back rising from the seat base, transversely spaced, parallel rails depending from the bottom of the seat base, each rail having fore and aft portions and each rail further having transverse walls defining apertures through the rail at longitudinally spaced intervals along the rails both fore and aft on the rail; a transverse pivot bolt lodged in transverse apertures of the parallel rails in the fore portion thereof, a central compression spring freely bearing against the seat base aft of the pivot bolt, a spring cradle secured in a fixed position with respect to the seat post by said seat post clamp, forward stops on the cradle adapted to register against the bottom of the seat base, a central aft spring cradle cup adapted to freely receive the lower end of the compression spring, said seat base having a perimeter transversly broader aft than forward.

7. Apparatus in accordance with claim 6 further comprising a shell secured to the bottom of the seat base between the seat base rails, depending side walls on the shell parallel to said rails, and walls in said side walls defining transverse apertures coinciding with the defined apertures in the seat base rails.

8. Apparatus in accordance with claim 6 or 7 wherein said spring cradle comprises side bars fixed to said spring cup and extending forward to include said forward stops, each stop comprising a limb extending from a bar upwardly towards said seat base bottom, limb walls defining an aperture in each limb adapted to receive said pivot bolt, each limb further having a seat bottom contact foot normal to said limb.

9. Apparatus in accordance with claim 8 wherein each side bar further comprises transverse walls defining transversely aligned apertures in the side bars adjacent the limbs and transverse walls defining transversely aligned apertures between the cup and the limb.