Bicycle gearshift with improved precision control

Patent metadata

Field	Value
Publication number	US-9505462-B2
Application number	US-201414186248-A
Country	US
Kind code	B2
Filing date	Feb 21, 2014
Priority date	Feb 22, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

The present invention refers to a bicycle gearshift with improved precision control, comprising a kinematic mechanism in the form of a four-bar linkage with a base body and a mobile body connected together through a pair of connecting rods articulated to the base body and to the mobile body at four pin elements, each pair of opposite pin elements of the four pin elements defining a diagonal of the four-bar linkage kinematic mechanism, and a first attachment group of the base body to a bicycle frame, the mobile body being connected to a chain guide at a second attachment group, the four-bar linkage kinematic mechanism being associated with gearshift actuation means suitable for deforming the four-bar linkage kinematic mechanism so as to determine a displacement of the mobile body with respect to the base body and consequently a primary displacement of the chain guide in the axial direction with respect to the axis (A) of a cogset, and it is characterised in that the first attachment group comprises a kinematic mechanism for changing the relative angular position between the base body of the four-bar linkage kinematic mechanism and the frame as a function of the primary displacement of the chain guide.

First claim

What is claimed is:

1. Bicycle gearshift comprising a kinematic mechanism in the form of a four-bar linkage with a base body and a mobile body connected together through a pair of connecting rods articulated to said base body and to said mobile body at four pin elements, each pair of opposite pin elements of said four pin elements defining a diagonal of said four-bar linkage-kinematic mechanism, and a first attachment group of said base body for attaching to a bicycle frame, said mobile body being connected to a chain guide at a second attachment group, said four-bar linkage-kinematic mechanism being associated with gearshift actuation means suitable for deforming said four-bar linkage-kinematic mechanism so as to determine a displacement of said mobile body with respect to said base body and consequently a primary displacement of said chain guide in the axial direction with respect to the axis (A) of a cogset, wherein said first attachment group comprises a kinematic mechanism for changing the relative angular position between said base body of said four-bar linkage-kinematic mechanism and said frame as a function of said primary displacement of said chain guide,
wherein said first attachment group comprises a pin body having axis (C), intended to attach said base body to the frame of the bicycle, and
an interface for initially setting a relative angular position between said base body and said frame, said interface for initially setting the relative position between said base body and said frame comprising an attachment element in which said pin body engages and an adjustment screw that engages on said attachment element going into abutment against said frame.

2. Bicycle gearshift according to claim 1 , wherein said first attachment group comprises a shock-absorbing spring that engages at its first end with said rotary body and is constrained at its second end to said pin body.

3. Bicycle gearshift according to claim 1 , wherein said pinion is mounted in a fixedly connected manner on a pin element of said four pin elements, said pin element being fixedly connected to one of said connecting rods.

4. Bicycle gearshift according to claim 1 , wherein said pinion is mounted in a fixedly connected manner on an actuation pin substantially parallel to said pin elements, said actuation pin being set in rotation by said gearshift actuation means.

5. Bicycle gearshift according to claim 1 , wherein said gearshift actuation means are of the mechanical type and comprise:
a sheath seat for supporting a control cable comprising an outer sheath relative to which an inner cable core is free to slide, said sheath seat fixing said outer sheath in position in order to allow the sliding of said inner core;
a retaining clip of an end of said inner core, said sheath seat and said clip being arranged substantially at pin elements that are diagonally opposite in said four-bar linkage-kinematic mechanism;
a return spring arranged at one of said pin elements, to deform said four-bar linkage-kinematic mechanism in contrast to the traction imposed by a relative translation between said outer sheath and said inner core of said control cable.

6. Bicycle gearshift according to claim 1 , wherein said gearshift actuation means are of the motorised type and comprise a motor that drives the displacement of a shaft along a diagonal of said four-bar linkage-kinematic mechanism.

7. Bicycle gearshift according to claim 4 , wherein said gearshift actuation means are of the motorised type and comprise a motor that drives the displacement of a shaft along a diagonal of said four-bar linkage-kinematic mechanism and wherein said motor has an outlet axis perpendicular to said shaft, said motor driving a rotation of said actuation pin, said actuation pin bears a toothed spindle rotating as a unit with it in shape coupling with a rack formed on said shaft in order to determine a displacement in translation of said shaft.

8. Bicycle gearshift according to claim 7 , wherein said rack is guided in translation within a tubular portion of a guide shell mounted idly on said actuation pin, said guide shell enclosing said toothed spindle in order to keep said shape coupling between said toothed spindle and said rack.

9. Bicycle gearshift according to claim 1 , wherein said pin body of said first attachment group comprises a cylindrical bushing and a closing screw provided with an enlarged head suitable for going into engagement with said base body, said cylindrical bushing and closing screw being screwed into one another in order to hold said base body in the direction of said axis (C) of said pin body, sliding means for rotation being arranged between said base body and said pin body.

10. Bicycle gearshift according to claim 1 , wherein said second attachment group comprises a fifth pin element connected, at a first end, in a fixed manner to said chain guide and provided, at a second end, opposite the first, with a connection interface to said mobile body, said second attachment group comprising a chain tensioning spring, said fifth pin element acting as a support body for said chain tensioning spring.

11. Bicycle gearshift comprising a kinematic mechanism in the form of a four-bar linkage with a base body and a mobile body connected together through a pair of connecting rods articulated to said base body and to said mobile body at four pin elements, each pair of opposite pin elements of said four pin elements defining a diagonal of said four-bar linkage-kinematic mechanism, and a first attachment group of said base body for attaching to a bicycle frame, said mobile body being connected to a chain guide at a second attachment group, said four-bar linkage-kinematic mechanism being associated with gearshift actuation means suitable for deforming said four-bar linkage-kinematic mechanism so as to determine a displacement of said mobile body with respect to said base body and consequently a primary displacement of said chain guide in the axial direction with respect to the axis (A) of a cogset, wherein said first attachment group comprises a kinematic mechanism for changing the relative angular position between said base body of said four-bar linkage-kinematic mechanism and said frame as a function of said primary displacement of said chain guide,
wherein said first attachment group comprises a pin body having axis (C), intended to attach said base body to the frame of the bicycle, said kinematic mechanism for changing the relative angular position between said base body and said frame comprising:
a rotary body connected to said pin body so that a rotation of said rotary body determines a relative rotation about said axis (C) between said pin body and said base body;
a toothed sector formed on said rotary body; and
at least one pinion engaged with said toothed sector for transferring a controlled rotation to it, said pinion being directly or indirectly set in rotation by said gearshift actuation means,
wherein said first attachment group comprises an interface for initially setting a relative angular position between said base body and said frame, said interface for initially setting the relative position between said base body and said frame comprising an attachment element in which said pin body engages and an adjustment screw that engages on said attachment element going into abutment against said frame.

Assignees

• Campagnolo Srl

Inventors

• Pasqua Paolo
• Dal Prà Giuseppe

Classifications

• B62M9/126

  Chain guides; Mounting thereof · CPC title

• B62M9/1242 Primary

  characterised by the linkage mechanisms · CPC title

• B62M9/125

  Mounting the derailleur on the frame · CPC title