Suspension fork

• US 5,320,374 A
• Filed: 06/11/1991
• Issued: 06/14/1994
• Est. Priority Date: 06/11/1991
• Status: Expired due to Term

• Current Assignee: Cannondale Bicycle Corporation (Dorel Industries Incorporated)
• Original Assignee: Cannondale Bicycle Corporation (Dorel Industries Incorporated)
• Inventors: Farris, Mark S., Harrison, Michael A., Loftus, John M.
• Primary Examiner(s): HILL, MITCHELL
• Application Number:
  US07/713,673
• Time in Patent Office: 1,099 Days
• Field of Search: 280/276, 280/283, 280/284, 280/286, 280/274, 280/275, 280/277, 280/279, 280/280, 280/777, 188/322.17, 188/322.16, 188/266, 188/271, 188/381, 267/202, 267/216, 74/492, 464/117
• US Class Current: 280/276
• CPC Class Codes: B62K 21/20 resilient
• CPC Class Codes: B62K 25/08 for front wheel
• CPC Class Codes: F16F 9/16 involving only straight-line movement of the effective parts wing closers or openers with liquid piston brakes E05F3/04
• CPC Class Codes: F16F 9/3235 of cylinders F16F9/483 takes precedence

Abstract

There is disclosed herein a suspension fork assembly particularly for use with bicycles. The assembly comprises an outer steer tube which is adapted to be mounted in and extend through the head tube of the bicycle frame, and an inner steer tube telescopes within the outer steer tube. A shock absorbing system is provided within the tubes. The inner surface of the outer steer tube and the outer surface of the inner steer tube each have a plurality of axially arranged opposing longitudinal flat sections, such as four on each tube. A plurality of needle bearings are disposed between the tubes on these flat sections. This arrangement, with the needle bearings arranged on the flat sections between the inner and outer tubes, allows the two tubes to freely telescope in and out with respect to one another without any significant static friction, and also serves to transmit the torsional steering force from the outer tube to the inner tube. The needle bearings thus bear radial loads as well as maintain the in line relationship of the outer and inner tubes for rotational forces while allowing the two tubes to freely telescope.

Claims

1. A suspension fork assembly for bicycles comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces,

a like plurality of sets of needle bearings disposed normal to longitudinal axes of said tubes and between the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope with respect to each other, and enable torsional steering forces to be transferred from a handlebar adapted to be connected near one end of one of said tubes to a fork adapted to be connected near an end of the other of said tubes, and

one or more races positioned between the inner tube and the outer tube, the one or more races having a thickness which is adjustable to provide a desired radial clearance for the needle bearings.

2. A suspension fork as in claim 1 wherein said plurality of at least three axially extending longitudinal flat surfaces comprises four flat surfaces on each of said inner and outer tubes and four sets of needle bearings.

3. A suspension fork as in claim 1 wherein the inner wall of the outer tube comprises a plurality of axially extending longitudinal channels, the one or more races being disposed in the longitudinal channels.

4. A suspension fork assembly according to claim 1 wherein each of the one or more races has a thickness which varies, whereby changing the position of the race adjusts the clearance for the needle bearings.

5. A suspension fork assembly for bicycles comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces,

a like plurality of sets of needle bearings disposed normal to longitudinal axes of said tubes and between the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope with respect to each other, and enable torsional steering forces to be transferred from a handlebar adapted to be connected near one end of one of said tubes to a fork adapted to be connected near an end of the other of said tubes,

races disposed between the inner tube and the outer tube,

means for adjusting thickness of at least one of said races to adjust for clearance between the inner tube and the outer tube, and

a shock absorbing system disposed within and coupled between said inner and outer tubes.

6. A suspension fork assembly for bicycles comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces, and

a like plurality of sets of needle bearings disposed normal to longitudinal axes of said tubes and between the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope with respect to each other, and enable torsional steering forces to be transferred from a handlebar adapted to be connected near one end of one of said tubes to a fork adapted to be connected near the end of the other of said tubes,

wherein the inner wall of the outer tube comprises a plurality of axially extending longitudinal channels having a like plurality of races disposed in the longitudinal channels of the outer tube,

wherein the plurality of at least three axially extending longitudinal flat surfaces comprises four bearing races on each of said inner and outer tubes and four sets of needle bearings and said channels comprise four channels and said bearing members comprise four bearing members, two of the bearing members comprising elongated strips having parallel faces and adapted to be disposed in two of the respective channels normal to a radial line extending from the axis of the outer tube, and two of which comprise elongated strips having a first inwardly facing flat face disposed normal to a radial line extending from the axis of the outer tube and an outer face inclined with respect to the inwardly facing face thereof and cooperating with a mating inclined surface of two respective of said channels to enable adjustment of said latter two elongated strips to adjust bearing clearance.

7. A suspension fork as in claim 6 further including a shock absorbing system disposed within and coupled between said inner and outer tubes.

8. An axial and radial loading bearing suspension and steering assembly for vehicles and the like comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope but not rotate with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces,

a like plurality of sets of needle bearings disposed normal to longitudinal axes of the inner and outer tubes and between ad adjacent the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope but not rotate with respect to each other and the bearings to individually rotate with respect to the longitudinal axes of said tubes, and enable torsional steering forces to be transferred from a member adapted to be connected near one end of one of said tubes to another member adapted to be connected near an end of the other of said tubes, and

one or more races positioned between the inner tube and the outer tube, the thickness of the one or more races being adjustable to provide a desired radial clearance for the needle bearings.

9. A suspension and steering assembly as in claim 8 wherein said plurality of at least three axially extending longitudinal flat surfaces comprises four flat surfaces on each of said inner and outer tubes and four sets of needle bearings.

10. A suspension and steering assembly as in claim 8 wherein the inner wall of the outer tube comprises a plurality of at least three axially extending longitudinal channels having a like plurality of said races disposed therein.

11. A suspension and steering assembly according to claim 8 wherein each of the one or more races has a thickness which varies from, whereby changing the position of the race adjusts the clearance for the needle bearings.

12. An axial and radial load bearing suspension and steering assembly for vehicles and the like comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope but not rotate with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces,

a like plurality of sets of needle bearings disposed normal to longitudinal axes of said tubes and between and adjacent the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope but not rotate with respect to each other and the bearings to individually rotate with respect to the longitudinal axes of said tubes, and enable torsional steering forces to be transferred from a member adapted to be connected near one end of one of said tubes to another member adapted to be connected near an end of the other of said tubes,

a plurality of races disposed between the inner tube and the outer tube,

means for adjusting thickness of at least one of said races to adjust for clearance between the inner tube and the outer tube, and

a shock absorbing system disposed within and coupled between said inner and outer tubes.

13. An axial and radial load bearing suspension and steering assembly for vehicles and the like comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope but not rotate with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces, and

a like plurality of sets of needle bearings disposed normal to longitudinal axes of said tubes and between and adjacent the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope but not rotate with respect to each other and the needle bearings to individually rotate with respect to the longitudinal axes of said tubes, and enable torsional steering forces to be transferred from a member adapted to be connected near one end of one of said tubes to another member adapted to be connected near the end of the other of said tubes,

wherein the inner wall of the outer tube comprises a plurality of at least three axially extending longitudinal channels having a like plurality of said races disposed therein,

wherein the plurality of at least three axially extending longitudinal flat surfaces comprises four of said races on each of said inner and outer tubes and four sets of needle bearings, and said channels comprise four channels and said needle bearings comprise four needle bearings, two of the needle bearings comprising a first two strip members having parallel faces and adapted to be disposed in two of the respective channels normal to a radial line extending from the axis of the outer tube, and two of which comprise a second two strip members having a first inwardly facing flat face disposed normal to a radial line extending from the axis of the outer tube and an outer face inclined with respect to the inwardly facing face thereof and each cooperating with a mating surface of each of two respective of said channels to enable adjustment of said second two strip members to adjust bearing clearance.

14. A suspension and steering assembly as in claim 13 further including a shock absorbing system disposed within and coupled between said inner and outer tubes.

15. A suspension and steering assembly as in claim 13 wherein said plurality of at least three axially extending longitudinal flat surfaces comprises four flat surfaces on each of said inner and outer tubes and four sets of needle bearings.

16. A suspension and steering assembly as in claim 13 wherein said second two strip members can be adjusted in a direction perpendicular to two of the respective axially extending longitudinal flat surfaces of the outer tube.

17. A suspension and steering assembly as in claim 13 wherein the second two strip members can be adjusted parallel to two of the respective axially extending longitudinal flat surfaces.

18. An axial and radial load bearing suspension and steering assembly for vehicles and the like comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope but not rotate with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces,

a like plurality of cages and a like plurality of sets of needle bearings in the cages, the cages disposed normal to longitudinal axes of said tubes and between and adjacent the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope but not rotate with respect to each other and the bearings to individually rotate with respect to the longitudinal axes of said tubes, and enable torsional steering forces to be transferred from a member adapted to be connected near one end of one of said tubes to another member adapted to be connected near an end of the other of said tubes,

the inner wall of the outer tube comprises a plurality of axially extending longitudinal channels having a plurality of bearing races disposed therein, the bearing races having adjustable thickness to provide a desired radial clearance for the needle bearings.

19. A suspension and steering assembly according to claim 18 wherein each of the bearing race members has a thickness which varies, whereby changing the position of the bearing race member adjusts the clearance for the needle bearings.

20. An axial and radial load bearing suspension and steering assembly for vehicles and the like comprising an elongated inner tube and an elongated outer tube coaxially mounted together and adapted to telescope but not rotate with respect to each other, comprising

the inner tube having an outer wall with a plurality of at least three axially extending longitudinal flat surfaces,

the outer tube having an inner wall with a like plurality of axially extending longitudinal flat surfaces,

a like plurality of sets of needle bearings in cages disposed normal to longitudinal axes of said tubes and between and adjacent the respective flat surfaces of the outer wall of the inner tube and the flat surfaces of the outer tube, whereby the flat surfaces of the inner and outer tubes in combination with the sets of needle bearings allow the tubes to telescope but not rotate with respect to each other and the bearings to individually rotate with respect to the longitudinal axes of said tubes, and enable torsional steering forces to be transferred from a member adapted to be connected near one end of one of said tubes to another member adapted to be connected near the end of the other of said tubes,

the inner wall of the outer tube comprises a plurality of axially extending longitudinal channels having a plurality of adjustable bearing races disposed therein, and

a shock absorbing system disposed within and coupled between said inner and outer tubes.

21. A suspension and steering assembly in claim 20 comprising four flat surfaces on each of said inner and outer tubes and four sets of needle bearings.