GB2085378A - Cycle frames - Google Patents

Abstract

A cycle frame comprising a composite body having two sheets of material separated by and bonded to a core and mounting means separately located at forward, rearward, upper and lower regions of the body respectively to receive swivelable front forks; a rear wheel assembly; a saddle assembly and driving mechanism to be coupled with the rear wheel assembly. The frame is produced from a blank of composite sheet material having a core of honeycomb structure covered by metal on plastics sheet material.

Description

SPECIFICATION Improvements relating to cycle frames This invention relates to cycle frames.

In this specification the term 'cycle' is to be understood as including pedal powered and motor powered bicycles and tricycles whether chain, belt or shaft driven.

Traditionally pedal powered cycle frames have been constructed of pinned and brazed or welded metallic tube and rod and motor powered cycle frames of metallic tube, rod and/or sheet metal pinned and brazed or welded together.

Such frames are labour intensive to manufacture and particularly when cycles are to be used for competition purposes and a strong but very light frame is required they are very expensive to make.

The present invention has for its object the provision of an improved cycle frame which is light, strong and comparatively inexpensive to produce and which is suitable for all types of cycles.

According to the present invention there is provided a cycle frame comprising a composite body having two sheets of material separated by and bonded to a core and mounting means separately located at forward, rearward, upper and lower regions of the body respectively to receive swivelable front forks; a rear wheel assembly; a saddle assembly and driving mechanism to be coupled with the rear wheel assembly.

Preferably the frame has at least two limbs, a first limb extending between the mounting means respectively of the saddle assembly and the driving mechanism and a second limb extending between the first limb and the mounting means for the front forks. The frame may be in the form of a -V-with the second limb joining the first limb at the lower end of the latter. Alternatively the frame may be in the form of an inverted -L- with the second limb joining the first limb at the upper end of the latter.

The side faces of the frame may be of sheet metal, plastics or other material and the core of the frame may be an open, generally honeycomb, structure of metal, plastics, paper or other sheet material bonded to each of the side faces.

The edges of the frame may be provided with metal or plastics capping bonded thereto or these edges may be finished with a settable bonding material. The side faces and the edges may be reinforced at positions where locally applied loads are to be distributed through the frame. Lightening apertures may be formed through the frame at selected locations and the internal edges of these may be similarly capped or finished.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a side view of a composite body for a cycle frame embodying the invention, Figure 2 shows the frame of Figure 1 provided with mounting means separately located at different regions of the body, Figure 3 is a view in the direction of the arrow X in Figure 1, Figure 4 is a view in the direction of the arrow Y in Figure 1, Figure 5 is a view in the direction of the arrow A in Figure 1, Figure 6 is a view similar to Figure 3 with a pad member removed, Figure 7 is a sectional view along the lines D-D in Figure 1, Figure 8 is a typical sectional view along the lines B-B in Figure 1, Figure 9 is a sectional view along the lines C-C in Figure 1, Figure 10 is a view in the direction of the arrow Z in Figure 2, and Figures 11 to 16 are diagrammatic side views of various cycle frames embodying the invention.

Referring to the drawings, Figure 1 shows a composite body 1 for a cycle frame 2 (Figure 2). As is shown in Figure 5, the body 1 is formed of two sheets 3 and 4 separated by a core 5 and bonded thereto in a manner not shown. The composite material forming the body is commercially available and the body is cut to the shape shown in Figure 1, from a rectangular blank. The core 5 is formed in a manner not shown from a plurality of strips of material placed one on top of the other and each strip is bonded to an adjacent strip at regular intervals along its length. By separating the outermost strips, an open, generally honeycomb structure is formed. The sheets 3 and 4 are then bonded to the core so that each honeycomb face is covered by a sheet.

As shown in Figure 2, the body 1 is provided with various mounting means 6, 7, 8, 9 separately located at different regions of the body to form the frame 2, namely, forward, rearward, upper and lower regions to respectively receive swivelable front forks, a rear wheel assembly, a saddle assembly and a driving mechanism to be coupled to the rear wheel assembly, none of these latter items being shown in Figure 2.

As shown in Figures 1 and 2, the frame 2 has two limbs 10, 11. Limb 10 extends between mounting frames 8 and 9 while limb 11 extends between the limb 10 and the mounting means 6. As shown in Figure 2, the frame 2 is in the form of an inverted -Lwith the limb 11 joining the limb 10 at the upper end ofthe limb 10.

The edges of the frame 2 are provided with metal or plastics capping 12 bonded thereto although this may be dispensed with, as shown in Figure 1, in the region underlying the mounting means 7,8 for the rear wheel assembly and the saddle assembly. The mounting means 7,8 shown in Figure 2 are integral with each other. The mounting means 7 for the rear wheel assembly and the mounting means 9 for the driving mechanism are connected together on each side of the rear wheel (not shown) by a backstay 13 and a chainstal 14 in turn connected to each other by a bracket 15 for receiving the rear wheel (not shown).

The left hand end of each chainstay 14 is connected to the mounting means 9 which is in the form of a part cylindrical collar 40 which defines a bore 16 in which the driving mechanism is received. The collar 14 has integrally formed end-pieces 41 which are secured to the limb 10. As shown in Figure 1, bores 17, 171 are provided which extend through the capping 12 and the body 1. The capping 12 is provided with lugs 18 and widened portions 19 to respectively accommodate the bores 171, 17. Also, as shown in Figure 1, bores 20 are provided having axes which extend perpendicularly to those of bores 17,171.The purpose of the bores 17 is to receive bolts (not shown) extending through a reinforcing member 21 (Figure 2) to which the mounting means 6 is bonded while the mounting means 7,8 is secured to the body 1 by bolts (not shown) extending through the bores 171 and bores 22 in limb portions 42 of the mounting means 7,8. The portion ofthe mounting means 7, 8 between the bores 22 is a force fit and/or bonded to the body 1.

The bores 20 enable reinforcing members 23 (Figure 3) to be bolted one on each side of the limb 10.

The purpose of reinforcing members 21 and 23 is to locally applied loads through the frame.

As shown in Figures 1 and 2, the body 1 is provided with a blind hole 24 which is aligned with a bore 25 in the mounting means 7,8 when the latter is mounted in position. in use, the stem of a saddle (not shown) is received in the blind hole 24 and the bore 25. The mounting means 7, 8 is provided with means 26 for adjusting the height of the saddle (not shown) in known manner.

Referring to Figure 10, it can be seen that the means 26 comprises a pair of limbs 43 which define a gap 44 in communication with the bore 25. A bore (not shown) extends through the limbs 43 and receives a bolt (not shown) for urging together of the limb 43. Figure 10 also shows a recess 44 for receiving the body 1 and two further recesses 45 for receiving the upper end of each backstay 13.

As shown in Figure 4, a pair of so-called nutserts 27 are provided for one of the bolts mounting the mounting means 7, 8 and are located in a recess 28 in the body 1 (Figure 1). If desired the remaining bolts may be secured in this manner. Each nutsert 27 is a cap-shaped insert of sheet material used for retaining a nut.

As shown in Figures 7 and 9, the various bores extending through the body 1 may be reinforced by capping sleeves 30 of suitable material.

In place of the capping 12 and the capping sleeves 30, the edges of the body and the internal edges of bores through the body may be finished with a settable bonding material (not shown).

The side faces 3, 4 of the body 1 may be of sheet metal, plastics or other material and the core 2 may be of metal, plastics, paper or other sheet material.

Aluminium or aluminium alloy is considered to be particularly suitable.

The capping 12 and the capping sleeves 30 are of any suitable metal or plastics. Again, aluminium or aluminium alloy is considered to be particularly suitable.

Figures 11 to 16 show diagrammatically various embodiments of cycle frame. The frame of the sports model shown in Figure 11 is somewhat similar to that of Figure 1. The frame of the sturdy "roadster" model of Figure 12 is in the form of a -V- while the frames shown in Figures 13to 15areeach in the form of an inverted L. The frame of Figure 13 is that of a child's cycle. Four lightening apertures 31 are provided as shown and these may be capped or finished as described above. The frame of Figure 14 is that of a sports model and four lightening apertures 31 are provided, the right hand aperture being of greater diameter than the other three.

Figure 15 shows the frame of a chopper type bicycle while Figure 16 shows the frame of a light moped.

Claims (10)

1. A cycle frame comprising a composite body having two sheets of material separated by and bonded to a core and mounting means separately located at forward, rearward, upper and lower regions of the body respectively to receive swivelable front forks; a rear wheel assembly; a saddle assembly and driving mechanism to be coupled with the rear wheel assembly.

2. Aframe according to claim 1 which has at leas two limbs, a first limb extending between the mounting means respectively of the saddle assembly and the driving mechanism and a second limb extending between the first limb and the mounting means for the front forks.

3. A frame according to claim 2 which is in the form of a -V- with a second limb joining the first limb at the lower end of the latter.

4. Aframe according to claim 2 which is in the form of an inverted -L- with the second limb joining the first limb at the upper end of the latter.

5. A frame according to any one of the preceding claims in which the side faces are of sheet metal, plastics or other material and the core is an open, generally honeycomb, structure of metal, plastics, paper or other sheet material bonded to each of the side faces.

6. Aframe according to claim 5 in which the edges of the frame are provided with metal or plastics capping bonded thereto.

7. Aframe according to claim 5 in which the edges of the frame are finished with a settable bonding material.

8. A frame according to any one of claims 5 to 7 in which the side faces and the edges are reinforced at positions where locally applied loads are to be distributed through the frame.

9. A frame according to any one of claims 5 to 8 in which lightening apertures are formed through the frame at selected locations and the internal edges of these are similarly capped or finished.

10. A cycle frame substantially as herein de scribedwith reference to any one of Figures 1 to 16 of the accompanying drawings.