This document describes a fuel injector for an internal combustion engine. It has a valve body with an annular groove that connects to oblique passages, allowing fuel to enter from different angles without bending the valve needle. During injection, fuel jets issue from the passages simultaneously and with equal force, balancing each other out to avoid bending the needle. The angular position of the valve body does not need to be exact, simplifying assembly.

1. * GB780153 (A)
Description: GB780153 (A) ? 1957-07-31
Improvements in fuel injectors for internal combustion engines
Description of GB780153 (A)
PATENT SPECIFICATION
Date of Application and filing Complete Specification: Nov. 30, 1955.
Application made in France on Dec. 21, 1954.
780,153 No. 34261/55.
Complete Specification Published: July 31, 1957.
Index at acceptance:-Class 7(3), B2J(1B6O:15:18B:21).
International Classification:-FO2f.
COMPLETE SPECIFICATION
Improvements in Fuel Injectors for Internal Combustion Engines I,
GERMAIN TESSIER, of 1, Impasse de Margnolles, Caluire, Rh6ne, France,
a French Citizen, do hereby declare the invention for which I pray
that a patent may be granted to me, and the method by which it is to
be performed to be particularly described in and by the following
statement:-
This invention relates to fuel injectors for internal combustion
engines, of the kind comprising a fuel nozzle co-operating with a
spring-loaded valve actuated by a piston submitted to the action of
the liquid fuel forced by the injection pump.
It has already been proposed to provide the cylinder of the
valve-actuating piston in the form of a member spaced from the inner
wall of the injector body and carried by an upper flanged portion of
the valve body disposed within the said injector body, the valve body
being formed with an elongated axial chamber adapted to receive with a
substantial radial clearance the valve plunger or needle which
controls the fuel-spraying holes at the lower end of the said valve
body, and fuel being forced into the said elongated chamber through an
oblique passage bored through the upper flanged portion of the valve
body and in communication with a corresponding fuel passage provided
in the wall of the injector body. This construction of course requires
that the passage in the valve body and the passage in the injector

2. body be in perfect mutual registration, which complicates the mounting
of the injector. Moreover the liquid jet issuing from the passage in
the valve body impinges against the valve needle and thus exerts on
the latter a lateral force which tends to bend it.
The present invention has for its object to provide a fuel injector of
the type set out in the preceding paragraph, wherein the valve body
need not be set at an exact angular position with respect to the valve
body, and wherein the flow of liquid fuel during the injection period
will not cause any bending force on the valve needle.
According to the invention in a fuel injector of the type described in
the first two paragraphs above the upper face of the flanged portion
of the valve body is formed 50 with an annular groove adapted to
register with the opening of the fuel passage in the injector body,
the said groove communicating with the elongated axial chamber through
a plurality of oblique passages provided in the 55 said portion at
substantially regular angular intervals.
The upper end of the elongated axial chamber is preferably of
increased diameter to form a fuel-receiving space in which the 60 said
oblique passages open.
It will be appreciated that the annular groove forms a distributing
connection between the passage in the injector body and the oblique
passages provided in the flanged 65 upper portion of the valve body
whatever may be the angular position of the latter with respect to the
former, whereby any difficulty in the mounting of the injector is
avoided.
Moreover during the injection period the fuel 70 jets issue from all
the oblique passages at the same time and substantially with the same
force, whereby the valve needle is submitted to a number of lateral
forces directed in every direction, which balance each other. Due to
75 the presence of the enlarged upper portion of the axial chamber a
space is provided wherein the fuel issuing from the oblique canals may
collect to be regularly distributed on the whole annular passage
between the wall of 80 the said axial chamber and the periphery of the
valve needle.
The annexed drawing illustrates a general longitudinal section of a
fuel injector according to this invention. 85 The injector illustrated
comprises a tubular inner member or valve body 1 having a closed
conical lower end provided with a number of calibrated perforations or
spraying holes la for the injection of the fuel into the engine 90 2
780,153 cylinder. The blind lower end of the inner bore of member 1 is
also conical and it forms a seat for a needle valve 2 of smaller
diameter than the corresponding portion of the bore of member 1. The
upper end of needle 2 is solid with a cylindrical piston 3 which is
slidable in a cylinder solid with the upper flanged portion lb of

3. member 1. Piston 3 has an upper extension 4 adapted to receive the
action of the loading spring, as explained below.
The upper face of portion lb is formed with a circular groove lc
co-axially disposed with respect to the bore of member 1. Groove lc
communicates by a plurality of regularly disposed oblique passages Id
with an inner annular chamber le formed in the flanged portion lb of
member 1.
Member 1 is engaged into a socket 5 which forms the lower half of the
body of the injector. Socket 5 has a lower tubular extension adapted
to receive the lower portion of member 1, while the socket itself
houses the flanged portion lb. The upper end of socket 5 is internally
screw-threaded for receiving the correspondingly screw-threaded lower
end of a sleeve 6 which forms the upper half of the injector body. The
inner bore of sleeve 6 is of substantially larger diameter than the
upper portion of member 1, whereby there is left an intermediate
annular space a.
A strong spring 7 is disposed in the upper portion of sleeve 6, this
spring acting on a slidable washer 8 which rests on the abovedescribed
extension 4. The upper end of spring 7 bears against a plug 9 screwed
in the upper end of sleeve 6, the said plug being solid with a
downwardly extending rod 10 adapted to form an inner axial guide for
spring 7. A passage l l is provided through rod 10 and plug 9 for the
outlet of the fuel which may have leaked around piston 3.
The upper end of sleeve 6 has a lateral extension 6a which receives a
screw-threaded coupling 12 connected with the fuel inlet pipe, a
filter 13 being disposed below this coupling.
The fuel which has passed through filter 13 passes through a
horizontal passage 14 which opens into a vertical canal 15 extending
longitudinally through the wall of sleeve 6 in such a manner as to
open into groove le.
The arrangement is such that the lower end of sleeve 6 bears in a
fuel-tight manner against the upper annular face of portion lb,
whereby fuel is prevented from leaking from groove lc.
The injector described operates in the conventional manner. At each
fuel-delivering stroke of the pump, fuel from passage 15 is forced
into groove lc and thence through passages Id. Piston 3 is raised
against the action of spring 7 and fuel may therefore flow downwardly
from the annular chamber le to be injected into the engine cylinder
through perforations la. The angular position of the 65 flanged
portion lb with respect to the upper half 6 of the injector body is
without any importance and the actions exerted on the valve needle 2
by the fuel jets issuing from the oblique passages Id balance each
other, 70 whereby the needle is not submitted to any bending force.
The arrangement of the upper portion of the injector body may be o&

4. any kind.
Member 1 could be divided into two or more 75 parts; for instance the
lower portion which surrounds the needle valve 2 might be formed as a
separate member screwed or otherwise secured to the flanged upper
portion lb.
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