WO2006011174A1

WO2006011174A1 - Motor-scooter fork crown

Info

Publication number: WO2006011174A1
Application number: PCT/IT2005/000423
Authority: WO
Inventors: Loris Vignocchi
Original assignee: Marzocchi S.P.A.
Priority date: 2004-07-26
Filing date: 2005-07-21
Publication date: 2006-02-02
Also published as: ITMC20040101A1

Abstract

The present industrial invention refers to a motor-scooter fork crown composed of two identical box-shaped half-shells (SG) made of moulded iron, which are joined along the borders with a perimeter welding line.

Description

MOTOR-SCOOTER FORK CROWN

The present patent application for industrial invention refers to a new concept fork cross for motor-scooters.

As it is known, scooters use forks with limited-length stems joined by means of a special plate technically known as "cross". A traditional cross is composed of two lateral cylindrical hoses, each hose containing the upper end of one of the fork stems, and a central cylindrical conduit, basically with axis parallel to the hoses, where the lower end of a tubular pipe that supports the motor-scooter handle is inserted.

Each lateral hose is normally provided with an axial notch; the presence of the notch allows for reducing the cross-section of each hose by tightening suitable bolts externally on the hose.

In this way, each hose can be tightened and blocked at the top of the corresponding fork stem.

The stable connection between a traditional cross and the corresponding handle-holding hose is obtained when the lower end of the handle-holding hose is suitably inserted into the central cylindrical conduit of the cross and held in place by means of two or more bolts that transversally penetrate the conduit through suitable threaded holes ending outside the cross. In motor-scooters this type of crosses is obtained from a single moulded iron piece; this allows for obtaining a sturdy, although very heavy, structure.

Aluminium crosses have been produced as a remedy to excessive weight, thus combining good strength with limited weight. However, this type of cross is impaired by high construction costs, which can be tolerated in the case of motorcycles, especially if characterised by high performance and high price, but are not acceptable in the case of less expensive motor-scooters. The purpose of the present invention is to devise a cross characterised by strength, reduced weight and limited construction costs.

In view of the above, limited construction costs make the cross of the invention especially suitable for all types of motor-scooters, including high- powered high-performance motor-scooters, because it can withstand stresses related with heavy-duty service conditions.

According to the present invention, the cross is obtained by welding two identical box-shaped half-shells made of moulded iron, that is to say a strong, although inexpensive material. The box-shaped configuration of the half-shells allows for stable connection, resulting in an internally hollow cross characterised by limited total weight.

The construction costs of this type of cross are rather limited because of the simple, and therefore inexpensive, operations performed for construction.

The first operation consists in moulding the two box-shaped half-shells designed to be welded together to obtain the cross of the invention.

Since the cross of the invention is obtained from the combination of two identical half-shells, it appears evident that only one mould is needed to produce the required number of components (i.e. box-shaped half-shells).

Moreover, the second operation performed for the production of the cross of the invention does not involve high construction costs or significant difficulties; as mentioned above, it consists in perimeter welding (possibly arc welding) of each opposite pair of box-shaped half-shells. For illustrative purposes, arc discharge welding could also be used.

For major clarity the description of the ... according to the present invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, whereby:

- Figure 1 is an axonometric view of the cross of the invention obtained by welding two half-shells shown in Fig. 1 ;

- Figure 2 is an axonometric view of one of the two half-shells used to obtain the cross of the invention; - Figure 3 is a diagrammatic front view of the front-wheel assembly of a scooter provided with the cross of the invention.

With reference to the aforementioned figures, the cross of the invention (1 ) has a basically traditional general structure, with a central conduit (2) used to fix the lower end of the steering pipe (C) from which two lateral arms (3) symmetrically start, being provided with lightening openings (3a) and ending with corresponding cylindrical hoses (4) used to tighten the upper ends of the stems (S) of a fork.

Within the traditional structure, the cross of the invention is provided with two threaded holes (5) transversally ending in the central conduit (2) and designed to receive corresponding bolts used to tighten the steering pipe (C).

Likewise, each hose (4) has an axial notch (4a) and is externally provided with a pair of threaded conduits (6) with horizontal axis affected by the notch (4a). Each threaded conduit (6) has two separate, although consecutive and perfectly aligned sectors, with a first external non-threaded section (6a) with lower length and a second internal threaded section (6b) with higher length.

When a screw is engaged and tightened in each of the conduits (6), the two sections (6a and 6b) of the conduit (6) get closer, the notch (4a) closes and the hose (4) is energetically tightened around the upper end of the stem.

As mentioned above, the cross of the invention (1 ) is characterised by the fact that it is obtained from two identical box-shaped half-shells (SG) made of moulded iron, it being provided that the two half-shells (SG) are joined along the borders with a perimeter welding line (7).

Claims

1 ) Motor-scooter fork cross, of the type comprising a central conduit (2) used to fix the lower end of the steering pipe (C), from which two lateral arms (3) symmetrically start, ending with suitable cylindrical hoses (4) used to tighten the upper ends of the stems (S) of a fork, it being characterised by the fact that it is obtained from two identical box- shaped half-shells (SG) made of moulded iron joined along the borders with a perimeter welding line (7).

2) Cross as defined in the above claim, characterised in that each box- shaped half-shell (SG) comprises a central conduit (2), from which two lateral arms (3) symmetrically start, being provided with lightening openings (3a) and ending with corresponding cylindrical hoses (4), provided with an axial notch (4a) and externally provided with two threaded conduits (6) with horizontal axis affected by the same notch (4a).

3) Cross as defined in the above claim characterised in that each box-shaped half-shell (SG) comprises a threaded hole (5) transversally ending in the central conduit (2) and designed to receive a tightening bolt of the steering pipe (C).