DE102022108174A1 - Handlebar stem with a stem suspension for a bicycle - Google Patents

Abstract

The invention relates to a handlebar stem with a stem suspension for a bicycle. According to the invention, the stem (4), which is connected to a fork shaft (3) in the assembled state and projects forward in the direction of travel, consists of two stem parts, a stem part (7) on the fork shaft side and a stem part (8) on the handlebar side, to which a handlebar (5) can be attached . The fork shaft-side stem part (7) and the handlebar-side stem part (8) are pivotally connected by means of at least one elastomer-metal bushing (9) with a bushing axis (10) lying in the transverse direction, such that the elastomer-metal bushing (9) is made of a stable , circular cylindrical inner part as an inner tube (17) or bolt and an outer tube (16) with an elastomer layer (18) vulcanized in between, the elastomer-metal bushing (9) reducing its outer diameter in connection with the build-up of a preload in the elastomer layer ( 18) is pressed into a receiving eye (21). When driving, vertical shock loads, in particular those caused by the road, on a handlebar (5) are absorbed resiliently in the elastomer-metal bushing (9) by twisting, molecularly and restoringly in the elastomer layer (18).

Description

The invention relates to a handlebar stem with a stem suspension for a bicycle according to the preamble of claim 1.

The stem of a bicycle steering device is a component that is connected to a fork shaft and projects forward in the direction of travel and to which a handlebar is attached.

In order to increase the comfort of cycling, especially with vertical, road-induced shock loads on the handlebars, suspension systems for stems in different designs are known. For example, a front suspension as a parallelogram damper is out WO 94/18057 known. A disadvantage of this front suspension is the complex design with many components, especially spiral springs, and the required maintenance effort.

The object of the invention is, in contrast, to propose a handlebar stem with a stem suspension for a bicycle, with which riding comfort is increased, which is maintenance-free and can be used on various bicycles, the driving behavior remaining stable and safe despite the stem suspension. In addition, the handlebar stem with the stem suspension should be inexpensive to produce and should fit harmoniously into the appearance of a bicycle.

This task is solved with the features of claim 1. Advantageous further training is the subject of the subclaims.

According to claim 1, the stem, which in the assembled state is connected to a fork shaft and projects forward in the direction of travel, has a fork shaft-side stem part and a handlebar-side stem part, to which a handlebar can be attached. The stem particularly preferably has only these two stem parts.

The fork shaft-side stem part and the handlebar-side stem part are pivotally connected by means of at least one elastomer-metal bushing with a bushing axis lying in the transverse direction. For this purpose, the elastomer-metal bushing has a, preferably stable, cylindrical inner part as an inner tube or as a bolt and an outer tube with an elastomer layer vulcanized in between, the elastomer-metal bushing reducing its outer diameter in connection with the build-up of a preload in the elastomer layer is pressed into a recording eye.

The handlebar-side stem part is connected to the cylindrical inner part and the fork shaft-side stem part is connected to the receiving eye, in particular by means of a bushing clamp, whereby the receiving eye can also be an integral part of the fork shaft-side stem part.

Alternatively, the arrangement can also be reversed, in that the steerer shaft-side stem part is connected to the cylindrical inner part and the handlebar-side stem part is connected to the receiving eye, in particular by means of a bushing clamp, or the receiving eye can also be an integral part of the handlebar-side stem part.

With a stem suspension constructed in this way, vertical shock loads on a handlebar, in particular those caused by the road, are absorbed resiliently in the elastomer-metal bushing by twisting in a molecular and restoring manner in the elastomer layer. This increases driving comfort with stable and safe driving behavior. The arrangement is practically maintenance-free, can be manufactured inexpensively, can be used on various bicycles and, while being relatively low in weight, fits harmoniously into the appearance of a bicycle.

In a preferred specific embodiment, the fork shaft-side stem part is equipped with a conventional stem clamp for attachment to the upper end region of the fork shaft. Furthermore, a bushing clamp is arranged as a clamp with a direction rotated by 90 ° on the fork shaft-side stem part for a rotation-proof holder of the receiving eye. If necessary, the receiving eye can be formed directly and integrally on the fork shaft side stem part instead of the bushing clamp. The bushing clamp is preferably arranged facing forward from the fork shaft in the direction of the handlebars. However, arrangements of the bushing clamp on the fork shaft or protruding backwards from the fork shaft are also fundamentally possible.

The handlebar-side stem part has a handlebar clamp to which a fork part is connected. Two fork legs of the fork part are spaced apart according to the length of the inner part of the elastomer-metal bushing and surround it. By means of a clamping screw connection running through the inner part as an inner tube and through holes in the end regions of the fork legs, a torsion-proof connection is established between the handlebar clamp and thus a handlebar and the inner tube.

As stated above, the alternative, reverse arrangement should also be included, in which the bushing clamp is arranged on the handlebar-side stem part and the fork part is arranged on the fork shaft-side stem part.

In an advantageous development, two elastomer-metal bushings are pressed into a common receiving eye and lie together with their inner tubes in the receiving eye, possibly via a spacer. The recording eye is held in a socket clamp so that it cannot rotate. In addition, a torsion-proof connection is created between the handlebar-side stem part and the two inner tubes with a continuous clamping screw connection through the two inner tubes and through holes in the fork legs. When using two elastomer-metal bushings, a common, continuous inner tube can be used for both instead of two assigned inner tubes.

By using different elastomer-metal bushings with different spring stiffnesses, an adaptation to different types of bicycles, driving characteristics and subjective wishes and requirements can be easily achieved, with the range of variation being able to be increased by using two elastomer-metal bushings. As can be seen, after loosening the bushing clamp and the clamping screw connection, a mounting eye with one or two elastomer-metal bushings can easily be exchanged for another bushing with different spring properties.

In an expedient further development, at least one stop element is connected to the inner part by screwing and/or welding and/or gluing and/or molding, which protrudes radially into a window recess, preferably of the receiving eye, with a clearance that limits a pivoting path of the inner part. The stop element can have a shock-absorbing elastomer pad.

The window recess, preferably in a longitudinally central receiving eye area, is here advantageously covered with the socket clamp against environmental influences.

The stop element limits the spring travel, both the compression and rebound travel, in the event of very strong shock loads on the handlebars, which contributes to driving safety, especially under extreme loads, and on the other hand enables the possibility of a relatively soft, comfortable suspension for trips with low shock loads on the handlebars.

Slotted bushings that are known and are easy to adapt and optimize are particularly suitable as elastomer-metal bushings. In the manufactured state, such a slotted bushing has a longitudinal slot in the outer tube and a V-shaped, associated longitudinal slot in the elastomer layer, possibly also through an intermediate plate in the elastomer layer. When manufactured, the slotted bushing has a larger outer diameter than the inner diameter of the receiving eye. By reducing the outer diameter of the slotted bushing when it is pressed into the receiving eye, the longitudinal slots are closed and the preload is built up in the elastomer layer.

Instead of slotted bushings, known calibratable elastomer-metal bushings can optionally also be used with a closed outer tube which, in the manufactured state, has a larger outside diameter than the inside diameter of the receiving eye. Here too, a preload is built up in the elastomer layer by reducing the outer diameter of the elastomer-metal bushing when it is pressed into the receiving eye.

In addition, a bicycle with a handlebar stem with a stem suspension is claimed according to one of the claims.

The invention is further explained by way of example using a drawing.

• 1 eine perspektivische Draufsicht von oben auf einen vorderen oberen Rahmenbereich eines Fahrrads mit einem Lenkervorbau,
• 2 eine Ansicht entsprechend 1 mit einer teilweise geschnittenen Buchsenschelle des Lenkervorbaus,
• 3 einen vertikalen Längsschnitt entlang der Linie A-A aus 1, und
• 4 eine stirnseitige Ansicht einer Elastomer-Metall-Buchse als Schlitzbuchse im Herstellzustand.

Show it:

• 1 a perspective top view from above of a front upper frame area of a bicycle with a handlebar stem,
• 2 a view accordingly 1 with a partially cut bushing clamp of the handlebar stem,
• 3 a vertical longitudinal section along line AA 1 , and
• 4 a front view of an elastomer-metal bushing as a slotted bushing in the manufactured state.

In 1 until 3 is an upper front area of a bicycle frame 1 with a head tube 2 and a fork shaft 3 accommodated therein and a handlebar stem 4 with part of a handlebar 5 is shown.

The handlebar stem 4 is connected to a stem clamp 6 at the upper end of the fork shaft 3 protruding from the head tube 2.

In the exemplary embodiment shown, the handlebar stem 4 consists of a fork shaft-side stem part 7 and a handlebar-side stem part 8, which are connected by means of an elastomer-metal bushing 9 to a pivot axis 10 lying in the transverse direction in such a way that a spring-loaded, restoring pivoting movement of the handlebar 5 follows above and below is possible with appropriate handlebar loads.

The handlebar-side stem part 8 has a conventional front handlebar clamp 11 in which the handlebar 5 is received and held. A fork part 12 with flat, spaced fork legs 13, 14, which have through holes in their end regions, adjoins the handlebar clamp 11 in the direction of the fork shaft 3.

The fork shaft-side stem part 7 has the usual stem clamp 6 and a further clamping device as a socket clamp 15, the direction of which is rotated by 90 ° to the stem clamp 6 and runs in the transverse direction. The elastomer-metal bushing 9 is contained in the bushing clamp 15 and is clamped in such a way that it cannot rotate, as can be seen in particular from the sectional view 3 is visible.

How out 3 and from the front view of the elastomer-metal bushing 9 in the manufactured state 4 As can be seen, this is constructed from the outside to the inside with an outer tube 16, a stable inner tube 17 and an elastomer layer 18 between the outer tube 16 and the inner tube 17, with a tubular intermediate plate 19 also being vulcanized into the elastomer layer 18.

How out 4 As can be seen, the elastomer-metal bushing 9, as a so-called slotted bushing, has a longitudinal slot 20 in the manufactured state, which extends in a V-shape through the outer tube 16 to the inner tube 17. The elastomer metal bushing 9 after 4 is pressed into a receiving eye 21 with a slightly smaller inner diameter, whereby the longitudinal slot 20 is closed and a preload is built up in the elastomer layer 18. The receiving eye 21 with the pressed-in elastomer-metal bushing is removed (in a reduced version). 3 visible. The receiving eye 21 is received in the bushing clamp 15 of the fork shaft-side stem part 7 and held in a rotationally fixed manner.

The fork part 12 of the handlebar-side stem part 8 includes, with its fork legs 13, 14, the elastomer-metal bushing 9 along the length of its inner tube 17, the fork legs 13, 14 being connected in a rotationally fixed manner to the inner tube 17 by a clamping screw connection 22. The clamping screw connection 22 has a screw bolt 23 which is inserted through the inner tube 17 and holes in the fork legs 13, 14. The clamping screw connection 22 and the inner tube length are dimensioned such that the fork legs 13, 14 can be freely pivoted relative to the bushing clamp 15 connected to the fork-side stem part 7 and the receiving eye 21 held therein and the pivoting movements are only recorded in the elastomer layer 18.

In the top view 2 the socket clamp 15 is shown cut open in its upper area, which reveals a stop element 24, which is connected in a nose-shaped manner, projecting radially from the inner tube 17 in a longitudinally central area. When the handlebar 5 deflects downward, the stop element 24 pivots in the illustration 2 forward and when the handlebar 5 rebounds upward, the stop element 24 pivots backwards against associated walls of a window cutout 25 of the receiving eye 21, into which the stop element 24 protrudes, covered by the socket clamp 15. At least in the stop area, the stop element 24 is provided with an elastomer pad. In principle, a travel-limiting stop can also be arranged outside the elastomer-metal bushing.

From the in 2 In the specific embodiment shown, it can also be seen that the elastomer-metal bushing 9 can also be designed in two parts, here with a continuous inner tube 17 and two tube sections of the receiving eye 21, between which a spacer ring 26 is arranged, which forms the window cutout 25 with an annular opening .

Reference symbol list

1

Bicycle frame

2

Control tube

3

steerer tube

4

Handlebar stem

5

Handlebars

6

Stem clamp

7

Fork shaft side stem part

8th

handlebar-side stem part

9

Elastomeric metal bushing

10

Pivot axis

11

Handlebar clamp

12

Fork part

13

Fork leg

14

Fork leg

15

Bushing clamp

16

Outer tube

17

inner tube

18

Elastomer layer

19

Intermediate plate

20

Longitudinal slot

21

Recording eye

22

Tension screw connection

23

screw bolts

24

stop element

25

window cutout

26

Spacer ring

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 9418057 [0003]

Claims (10)

Handlebar stem with a stem suspension for a bicycle, characterized in that the stem (4), which in the assembled state is connected to a fork shaft (3) and projects forward in the direction of travel, has a fork shaft-side stem part (7) and a handlebar-side stem part (8), on which a handlebar (5) can be attached so that the fork shaft-side stem part (7) and the handlebar-side stem part (8) are pivotally connected by means of at least one elastomer-metal bushing (9) with a bushing axis (10) lying in the transverse direction, in such a way that the elastomeric Metal bushing (9) has a cylindrical inner part as an inner tube (17) or as a bolt and an outer tube (16) with an elastomer layer (18) vulcanized in between, the elastomer-metal bushing (9) reducing its outer diameter in connection with the Building up a preload in the elastomer layer (18) is pressed into a receiving eye (21), and that the handlebar-side stem part (8) with the cylindrical inner part (17) and the fork shaft-side stem part (7) with the receiving eye (21), preferably by means of a Bushing clamp (15), or that the receiving eye (21) is an integral part of the fork shaft-side stem part (4), or that, alternatively, in the reverse arrangement, the fork shaft-side stem part (7) with the cylindrical inner part (17) and the handlebar-side stem part (8) is connected to the receiving eye (21), preferably with a socket clamp (15), or that the receiving eye (21) is an integral part of the handlebar-side stem part (8). Handlebar stem after Claim 1 , characterized in that the fork shaft-side stem part (7) has a stem clamp (6) for fastening to the upper end region of the fork shaft (3) and a bushing clamp (15) arranged with a direction rotated by 90 ° for holding the receiving eye (21) in a rotation-proof manner , whereby, if necessary, instead of the bushing clamp (15), an integral receiving eye (21) can be formed on the fork shaft-side stem part (7), and that the bushing clamp (15) preferably points forward from the fork shaft (3) in the handlebar direction or, if necessary, backwards or on the Fork shaft (3) is arranged. Handlebar stem after Claim 1 or Claim 2 , characterized in that the handlebar-side stem part (8) has a handlebar clamp (11) to which a fork part (12) is connected, that two fork legs (13, 14) of the fork part (12) correspond to the length of the inner part (17). Elastomer-metal bushing (9) are spaced apart and encompass them, and that a torsion-proof connection between the handlebar clamp ( 11) and inner tube (17) are made. Handlebar stem according to one of the Claims 1 until 3 , characterized in that two elastomer-metal bushings are pressed into a common receiving eye (21) and rest against each other in the receiving eye (21) with their inner tubes, if necessary via a spacer (26), that the receiving eye (21) is in a socket clamp (15) is held in a torsion-proof manner and that a torsion-proof connection between the handlebar-side stem part (8) and the two inner tubes (17) is established with a continuous clamping screw connection (22) through the two inner tubes (179 and through holes in the fork legs (13, 14). Handlebar stem after Claim 4 , characterized in that instead of the two adjacent inner tubes, a common, continuous inner tube (17) is used. Handlebar stem according to one of the Claims 1 until 5 , characterized in that at least one stop element (24) is connected to the inner part (17), preferably in a longitudinally central region, by screwing and/or welding and/or gluing and/or molding, and that the at least stop element (24) is radial protrudes into a window recess (25), in particular of the receiving eye (21), with a clearance that limits a pivoting path of the inner part (17). Handlebar stem after Claim 6 , characterized in that the stop element (24) has an elastomer pad. Handlebar stem according to one of the Claims 1 until 7 , characterized in that for one or possibly both elastomer-metal bushings () a so-called slotted bushing is used with, in the manufactured state, a longitudinal slot (20) in the outer tube (16) and a V-shaped, continuous, assigned longitudinal slot in the elastomer layer ( 18) if necessary also continuously through an intermediate plate (19) in the elastomer layer (18), so that the elastomer-metal bushing (9) in the manufactured state has a larger outer diameter than the inner diameter of the receiving eye (21), and that the elastomer-metal bushing (9) is pressed into the receiving eye (21) by reducing its outer diameter, closing the longitudinal slots (20) and building up a preload in the elastomer layer (18). Handlebar stem according to one of the Claims 1 until 7 , characterized in that the one or possibly both elastomer-metal bushings (9) is a so-called calibratable elastomer-metal bushing with a closed outer tube (16) and, in the manufactured state, a larger outer diameter than the inner diameter of the receiving eye (21), and that Elastomer-metal bushing (9) is pressed into the receiving eye (21) while reducing its outer diameter and building up a preload in the elastomer layer (18). Bicycle with a handlebar stem (4) with a stem suspension according to one of the preceding claims, in particular in such a way that vertical, in particular road-induced, shock loads on a handlebar (5) occurring during a ride are resiliently absorbed in the elastomer-metal bushing (9) by molecular rotation and are absorbed restoringly in the elastomer layer (18).

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