Pipes and tubular conduits – Flexible – Braided – interlaced – knitted or woven
Reexamination Certificate
2002-11-25
2004-05-18
Brinson, Patrick (Department: 3752)
Pipes and tubular conduits
Flexible
Braided, interlaced, knitted or woven
C138S137000, C138S141000, C138S124000
Reexamination Certificate
active
06736167
ABSTRACT:
This application claims the benefit of and priority from Japanese Application No. 2001-360377 filed Nov. 27, 2001, the content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to a brake hose having two reinforcing yarn layers including a lower yarn layer and an upper yarn layer in a rubber base.
2. Description of the Related Art
A brake hose known in the conventional art is shown in
FIG. 7
(JP 06-201076A).
FIG. 7
is a cross-section of the main components of a conventional brake hose
200
. Because the brake hose
200
must have high resistance against brake fluid pressure, it is formed from several layers of rubber and fiber yarn. The brake hose
200
comprises an inner tube rubber layer
202
, a lower yarn layer
204
, an intermediate rubber layer
206
, an outer yarn layer
208
, and a cover rubber layer
210
.
The brake hose
200
is required to meet a higher pressure resistance standard than a coolant system hose or a fuel system hose. As fluid temperatures and pressure levels of automobile system have increased in recent years, the demand for higher pressure resistance has increased as well.
The pressure from the fluid flowing in the flow path
201
inside the brake hose
200
is transmitted from the inner circumference area of the brake hose
200
to the outer circumference area thereof. In other words, the pressure is transmitted to the inner tube rubber layer
202
, the lower yarn layer
204
, the intermediate rubber layer
206
, the upper yarn layer
208
and the cover rubber layer
210
, causing each layer to expand. Each layer has a binding force that operates against the pressure exerted by the fluid and inhibits expansion of such layer. The inner tube rubber layer
202
, the intermediate rubber layer
206
and the cover rubber layer
210
are highly elastic, and are responsible for no more than 10% of the total binding force, while the majority of the binding force is possessed by the lower yarn layer
204
and the upper yarn layer
208
. Consequently, increasing the binding force of the lower yarn layer
204
and the upper yarn layer
208
increases the durability and expansion resistance (i.e., resistance to cubical expansion) provided by the brake hose
200
. As a result, increasing both of these characteristics by changing the type of yarn material used and the braiding method of the yarn layers has been examined.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a brake hose that offers increased durability and expansion resistance.
In accordance with one embodiment of the present invention, a brake hose comprises reinforcing layers in a rubber base. The brake hose comprising an inner tube rubber layer that is made of a rubber material and has a flow path for flowing fluid; a lower yarn layer formed by braiding lower yarn around the inner tube rubber layer; an intermediate rubber layer made of a rubber material and located around the lower yarn layer; an upper yarn layer formed by braiding upper yarn around the intermediate rubber layer; and a cover rubber layer formed around the upper yarn layer. The intermediate rubber layer is formed from a sheet material having a Mooney viscosity of 10-40 Mv (minimum Mooney value) at 145° C.
The Mooney viscosity is a value reflecting measurement of the viscosity of non-vulcanized rubber at 145° C. based on the K6300 test promulgated under JIS (Japanese Industrial Standards).
In the brake hose pertaining to the present invention, the pressure exerted by the fluid flowing in the flow path is transmitted from the inner circumference area of the brake hose to the outer circumference area thereof, i.e., from the interior of the rubber base to the lower yarn layer and the upper yarn layer, causing each such layer to expand. A binding force that restricts the expansion of the brake hose in resistance to the pressure from the fluid is generated. The rubber base is responsible for no more than 10% of the total binding force due to its high elasticity, while the majority of the binding force is exerted by the lower yarn layer and the upper yarn layer.
It is preferred that the intermediate rubber layer
16
have a thickness of 0.1-0.25 mm. This is because if the thickness is less than 0.1 mm, the intermediate rubber layer
16
becomes too thin and cannot be braided around the lower yarn layer
14
, while if the thickness exceeds 0.25 mm, the intermediate rubber layer is so thick that the intermediate rubber layer
16
functions as an elastic layer that permits displacement of the lower yarn layer
14
, and the displacement-inhibiting effect of the lower yarn layer is diminished.
As the rubber material for the sheet, EPDM, isobutylene-isoprene copolymer rubber (IIR) or natural rubber (NR) may be used. Using EPDM or IIR or a material comprising a mixture of the two permits a higher heat resistance because of the properties of such materials. EPDM refers to ethylene-&agr;-olefin-unconjugated diene copolymer (propylene as &agr;-olefin).
In a preferred embodiment of the intermediate rubber layer, such layer is formed to a thickness of 0.1-0.25 mm through the application of rubber cement. Rubber cement has a Mooney viscosity of 0, and can be sufficiently impregnated between the lower yarn strands of the lower yarn layer, thereby preventing displacement of the lower yarn. By forming the intermediate rubber layer formed from rubber cement to the above thickness, the intermediate rubber layer is sufficiently impregnated among the strands of the upper yarn of the upper yarn layer, and the desired operation and effect can be obtained.
REFERENCES:
patent: 4111237 (1978-09-01), Mutzner et al.
patent: 4431031 (1984-02-01), Ettlinger
patent: 4734305 (1988-03-01), Sugimoto et al.
patent: 5077108 (1991-12-01), Ozawa et al.
patent: 5279874 (1994-01-01), Ichikawa et al.
patent: 5445191 (1995-08-01), Green et al.
patent: 5526848 (1996-06-01), Terashima et al.
patent: 5660210 (1997-08-01), Ikeda et al.
patent: 5922811 (1999-07-01), Suzuki et al.
patent: 6037062 (2000-03-01), Tsutsumi et al.
patent: 6071582 (2000-06-01), Tangiku et al.
patent: 6220304 (2001-04-01), Horiba et al.
patent: 6626211 (2003-09-01), Mizutani et al.
patent: 1 156 251 (2001-11-01), None
patent: 06-201076 (1994-07-01), None
patent: WO 01/48412 (2001-07-01), None
Furui Kenichiro
Mizutani Satoshi
Ogawa Taizo
Brinson Patrick
Posz & Bethards, PLC
Toyoda Gosei Co,., Ltd.
LandOfFree
Brake hose and method for manufacturing brake hose does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Brake hose and method for manufacturing brake hose, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Brake hose and method for manufacturing brake hose will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3212405