FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION [See section 10; rule 13]
TITLE: “A TURBOCHARGER ASSEMBLY FOR AN ENGINE OF A VEHICLE”
Name and Address of the Applicant:
TATA MOTORS LIMITED of 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India.
Nationality: Indian
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
[001] Present disclosure, in general, relates to a field of automobiles. Particularly, but not exclusively, the present disclosure relates to an engine of a vehicle. Further embodiments of the present disclosure discloses a turbocharger assembly for the engine of the vehicle.
BACKGROUND OF THE DISCLOSURE
[002] Generally, automobiles such as cars and trucks include turbochargers which are driven by exhaust gas produced by internal combustion engine, in order to improve engine performance. Turbochargers aid in supplying more amount of air into the engine, which leads to efficient burning of fuel in each cycle, thereby increasing power output. Turbochargers generally include a turbine which is driven by the exhaust gases to rotate a compressor and create negative pressure to draw air into the engine. However, in the conventional turbochargers, sufficient negative pressure is created only after the turbine attains a threshold RPM. During low engine operating speeds, the exhaust gas flow generated may not be sufficient to drive the turbine beyond threshold RPMs. This leads to lag in power delivery of the engine [referred as turbo lag in the art], where there is a noticeable delay in the engine delivering the demanded power from a driver. This lag causes jerks and sluggish movement of the vehicle, which is undesired.
[003] Present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the known arts.
[004] The drawbacks/difficulties/disadvantages/limitations of the conventional techniques explained in the background section are just for exemplary purpose and the disclosure would never limit its scope only such limitations. A person skilled in the art would understand that this disclosure and below mentioned description may also solve other problems or overcome the other drawbacks/disadvantages of the conventional arts which are not explicitly captured above.
SUMMARY OF THE DISCLOSURE
[005] One or more shortcomings of the prior art are overcome by a turbocharger assembly as claimed and additional advantages are provided through configuration of the assembly as claimed in the present disclosure. Additional features and advantages are realized through the techniques

of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
[006] In a non-limiting embodiment of the present disclosure, a turbocharger assembly for an engine of a vehicle is disclosed. The turbocharger assembly includes a turbocharger having a compressor which is fluidly coupled to an intake manifold of the engine and a turbine fluidly coupled to an exhaust manifold of the engine. The turbocharger assembly includes a driving member which is rotatably coupled to an output of the engine, where the driving member is driven by the engine. Further, a clutch is coupled to the driving member to rotate along with the driving member, where the clutch is disposed on a shaft that is coupled to the compressor and the turbine. The clutch is configured to engage the driving member with the shaft to transmit rotational motion of the driving member to the shaft for operating the compressor for a first speed of the engine. Further, the clutch is also configured to disengage the driving member with the shaft to allow operation of the compressor by the turbine for a second speed greater than the first speed of the engine.
[007] This configuration of the turbocharger assembly mitigates a lag in power delivery of the engine, during low operating speeds of the engine. That is, the turbocharger assembly enables the compressor of the turbocharger to be rotated by the engine when the speed of the engine is low such that sufficient negative pressure is generated even when the exhaust gas flow is not capable of rotating the turbine at the required speed, thereby reducing or mitigating lag in power delivery. Further, the turbocharger assembly enables rotation of the compressor by the turbine once the speed of the engine is high, as the exhaust gasses are capable of rotating the turbine at required speeds, thus reducing load on the engine. The non-dependence on the engine for the rotation of the compressor at higher speeds improves the fuel efficiency of the engine.
[008] In an embodiment, the driving member and the clutch are coupled together through a drive unit.
[009] In an embodiment, turbocharger assembly includes a gear arrangement which is disposed between the clutch and the shaft. The gear arrangement increase speed ratio between the clutch and the shaft.

[010] In an embodiment, the driving member is one of a pulley, a sprocket and a gear.
[011] In an embodiment, the clutch is a freewheel.
[012] In an embodiment, the drive unit is one of a belt, a chain and a gear drive.
[013] In another non-limiting embodiment, a vehicle is disclosed. The vehicle includes an engine and a turbocharger assembly for the engine. The turbocharger assembly includes a compressor which is fluidly coupled to an intake manifold of the engine and a turbine fluidly coupled to an exhaust manifold of the engine. The turbocharger assembly includes a driving member which is rotatably coupled to an output of the engine to be driven by the engine. Further, a clutch is coupled to the driving member to rotate along with the driving member, where the clutch is disposed on a shaft that is coupled to the compressor and the turbine. The clutch is configured to engage the driving member with the shaft to transmit rotational motion of the driving member to the shaft for operating the compressor for a first speed of the engine. Further, the clutch is also configured to disengage the driving member with the shaft to allow operation of the compressor by the turbine for a second speed greater than the first speed of the engine. Additionally, the vehicle includes a transmission system which is connected to the engine. The transmission is configured to transmit power from the engine to wheels of the vehicle.
[014] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[015] The novel features and characteristics of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiments when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

[016] Fig. 1 illustrates a schematic view of a turbocharger assembly for an engine, depicting rotational motion is being transmitted from a driving member to a shaft, according to an embodiment of the present disclosure.
[017] Fig. 2 illustrates a schematic view of the turbocharger assembly for the engine, depicting rotational motion being transmitted from a turbine to the shaft, according to an embodiment of the present disclosure.
[018] Fig. 3 illustrates a schematic view of the turbocharger assembly with an auxiliary clutch positioned between a clutch and a shaft, according to another embodiment of the present disclosure.
[019] Fig. 4 illustrates a schematic view of the turbocharger assembly with a gear arrangement disposed between the drive unit and the shaft, according to another embodiment of the present disclosure.
[020] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the system and method illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[021] The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which forms the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that, the conception and specific embodiments disclosed may be readily utilized as a basis for modifying other devices, assemblies, system, methods and processes for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that, such equivalent construction and method do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristics of the disclosure, to its construction and features, together with further objects and advantages will be

better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
[022] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
[023] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
[024] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusions, such that a device or a system or a method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such device, assembly, system or method. In other words, one or more elements in a device or an assembly or a system or a method proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the device or system or method.
[025] Reference will now be made to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings. Wherever possible, same numerals have been used to refer to the same or like parts. The following paragraphs describe the present disclosure with reference to Figs. 1-4.
[026] Fig. 1 illustrates a turbocharger assembly (100) for an engine (1) of a vehicle [not shown in Figs]. In an embodiment, the vehicle may be but not limiting to a car, a sports utility vehicle (SUV), a multi utility vehicle (MUV), a light commercial vehicle (LCV), a heavy commercial vehicle (HCV) or any other type of vehicle that makes use of the turbocharger assembly (100).

The engine (1) of the vehicle may be an internal combustion engine which may be configured to operate on fuels such as including but not limited to petrol, diesel, compressed natural gas (CNG), liquefied petroleum gas, ethanol, hydrogen and any other type of fuel suitable for internal combustion. The engine (1) may be adapted to power the vehicle based on inputs received by a user, such as a driver. Further, the vehicle may include a transmission system [not shown in Figs] which may be connected to the engine (1). The transmission system may be configured to transmit power from the engine (1) to wheels of the vehicle. The transmission system may include a plurality of gears which are configured to receive the rotational motion from the engine (1) and may selectively vary the rotational motion transmitted to the wheels of the vehicle based on the selected gear.
[027] Further, the vehicle may include the turbocharger assembly (100) which may be a part of or may be associated with the engine (1). The turbocharger assembly (100) may include a turbocharger (6). The turbocharger (6) may include a compressor (6a) which may be fluidly coupled to an intake manifold (10) of the engine (1). Further, the turbocharger (6) may include a turbine (6b) which may be fluidly coupled to an exhaust manifold (9) of the engine (1). In an embodiment, the compressor (6a) and the turbine (6b) may be connected to each other through a shaft (5). The shaft (5) may be disposed such that an end of the shaft (5) may extend beyond the turbine (6b) and/or the compressor (6a). The turbine (6b) may receive exhaust gasses from the exhaust manifold (9) during operation of the engine (1). The exhaust gasses of the engine (1) may be channelized onto the turbine (6b) to rotate the turbine (6b). The speed at which the turbine (6b) rotates may depend on the flow rate of the exhaust gasses channelized onto the turbine (6b). Accordingly, higher the flow rate, higher the speed of the turbine (6b) and vice-versa. Further, the rotation of the turbine (6b) may be transmitted to the compressor (6a) through the shaft (5). The rotation of the compressor (6a) creates a negative pressure, which enables drawing and compressing of fresh air, which then is fed into the intake manifold (10) of the engine (1) in order to improve engine performance. That is, the turbocharger (6) aids in burning more fuel in each cycle of the engine (1), thereby increasing the power output.
[028] Referring back to Fig. 1, the turbocharger assembly (100) may include a driving member (2) which may be rotatably coupled to an output of the engine (1). The driving member (2) may be driven by the engine (1). In an embodiment, the driving member (2) may be at least one of a

pulley, a sprocket and a gear which may be coupled to a crankshaft [now shown in Figs] of the engine (1). Further, the turbocharger assembly (100) may include a clutch (4) which may be rotatably disposed on the shaft (5) and may be coupled to the driving member (2). The clutch (4) may be adapted to rotate along with the rotation of the driving member (2). In an embodiment, the clutch (4) may be one of a freewheel, a pinion and a gear. In an embodiment, clutch (4) may be configured to transmit rotational motion only from the driving member (2) onto the shaft (5) when the engine (1) may be operated at a first speed and act as a bearing when the rotational speed of the shaft (5) may be more than the driving member (2), which may correspond to the engine (1) being operated at a second speed. In an illustrated embodiment, the clutch (4) may be disposed on a portion of the shaft (5) which may be extending beyond the compressor (6a) such that the clutch (4) may be positioned adjacent to the compressor (6a). However, this should not be considered as a limitation as the clutch (4) may be disposed on a portion of the shaft (5) which may be extending beyond the turbine (6b) such that the clutch (4) may be positioned adjacent to the turbine (6b). The positioning of the clutch (4) adjacent to either the compressor (6a) or the turbine (6b) may be dependent on the orientation of the turbocharger (6) when coupled with the engine (1). Further as apparent from Fig. 1, the clutch (4) and the driving member (2) may be coupled to each other through a drive unit (3). In an embodiment, the drive unit (3) may be one of a belt, a chain and a gear drive which may be adapted to transmit rotational motion from the driving member (2) to the clutch (4).
[029] In an embodiment, the driving member (2) and the clutch (4) may be selected such that, the rotational speed of the driving member (2) may be amplified in the clutch (4). That is, the clutch (4) may be adapted to transmit rotational motion at substantially higher speeds to the shaft (5), when compared to the speed of the driving member (2). In an embodiment, the driving member (2) and the clutch (4) may be configured such that there exists a transmission ratio between the driving member (2) and the clutch (4) to transmit higher rotational speeds to the shaft (5). For example, diameter of the driving member (2) may be higher than the diameter of the clutch (4). The high transmission ratio between the driving member (2) and the clutch (4) may facilitate rotation of the compressor (6a) of the turbocharger (6) at high speeds to draw and compress air which then is fed into the intake manifold (10) of the engine (1) in order to improve engine performance.

[030] In an embodiment, the engine (1) may be operating at a first speed, where the first speed of the engine (1) may be the engine speed range at which the exhaust gasses produced by operation of the engine may not be sufficient to rotate the turbine (6b) for operating the turbocharger at required speed. At this operating condition of the engine (1), the clutch (4) may be configured to engage the driving member (2) with the shaft (5) to transmit rotational motion of the driving member (2) to the shaft (5) [as indicated in arrow heads], for operating the compressor (6a). That is, the clutch (4) may be configured to receive the rotational motion from the driving member (2) [thus, the engine (1)] and directly transfer such rotational motion to the shaft (5) of the turbocharger assembly (100). Rotation of the shaft (5) causes rotation of the compressor (6a) beyond desired speeds, which enables creation of sufficient negative pressure to draw and supply air into the engine (1). Thus, the turbocharger assembly (100) effectively operates the compressor (6a), even at low exhaust gas flow rates, thereby mitigating lag in power delivery of the engine (1) before the engine speed rises to the required speed to operate the turbocharger (6) by the exhaust gasses.
[031] Referring now to Fig. 2, an operation at a second speed of the engine is depicted. The second speed of the engine (1) may be the engine speed range at which the exhaust gasses may rotate the turbine (6b) [as indicated in arrow heads] at the required speed to operate the compressor (6a) at desired speeds, which enables the compressor (6a) to create sufficient negative pressure to draw and supply air into the engine (1). At the second speed of the engine (2), the clutch (4) may be configured to disengage the driving member (2) with the shaft (5) to allow operation of the compressor (6a) by the turbine (6b). That is, when the exhaust gasses rotate the turbine (6b) of the turbocharger (6), such rotational speed of the turbine (6b) may be greater than the rotational speed of the clutch (4). Therefore, upon the rotational speed of the shaft (5) being greater than the rotational speed of the clutch (4), the shaft (5) may be configured to rotate freely and independent of the driving member (2) such that the driving member (2) may not influence the working of the turbocharger (6), and the turbocharger (6) operates due to the exhaust gasses. The configuration of the turbocharger assembly (100) having the clutch (4) to disengage the shaft (5) and the driving member (2) ensures that the engine (1) only aids the turbocharger (6) to mitigate lag in power deliver at lower engine speeds and the turbocharger (6) does not require mechanical power from

the engine (1) at higher engine speeds, thereby does not decrease engine efficiency at higher engine speeds.
[032] In an embodiment, as seen in Fig. 3, the turbocharger assembly (100) may include an auxiliary clutch (7) which may be disposed between the clutch (4) and the shaft (5). The auxiliary clutch (7) may be configured to transmit rotational motion only from the clutch (4) onto the shaft
(5) and act as a bearing when the rotational speed of the shaft (5) may be more than the clutch (4).
The auxiliary clutch (7) facilitates transmission of rotational motion from the driving member (2)
for the first speed of the engine (1). Further, the auxiliary clutch (7) facilitates the shaft (5) to rotate
freely when the turbocharger (6) may operate based on the exhaust gasses, that is for the second
speed of the engine (1). In this manner, by virtue of the auxiliary clutch (7), the clutch (4) acts as
a freewheel or an overrunning clutch.
[033] In an embodiment, as seen in Fig. 4, the turbocharger assembly (100) may include a gear arrangement (8) disposed between the clutch (4) and the shaft (5). The gear arrangement (8) may be adapted to transmit rotational motion from the clutch (4) to the shaft (5). The gear arrangement (8) may be configured to amplify the rotational motion received from the clutch (4) and transmit the amplified rotational motion onto the shaft (5). That is, the gear arrangement (8) may be adapted to transmit rotational motion at substantially higher speeds to the shaft (5) when compared to the speed of the clutch (4). In an embodiment, the gear arrangement (8) may be including but not limited to gears connected in series, gears connected in parallel, sun and planetary gears and the like which increase the rotational speed received from the clutch (4).
[034] The gear arrangement (8) may facilitate rotation of the compressor (6a) of the turbocharger
(6) at the required speed to compress and forcefully feed air into the intake manifold (10) of the
engine (1) in order to improve engine performance. That is, the clutch (4), the driving member (2)
and the gear arrangement (8) facilitate operation of the compressor (6a) of the turbocharger (6)
even at lower engine speeds, at which the exhaust gasses cannot operate the turbocharger (6). Thus,
the turbocharger assembly (100) effectively operates the turbocharger (6) at low rates of exhaust
gas flow which are associated with low engine operating speeds to mitigate lag in power delivery
of the engine (1).

[035] In an embodiment, the turbocharger assembly (100) is simple in construction and easy to manufacture. Further, the turbocharger assembly (100) is easy to assemble and configure for effective engine operation. The turbocharger assembly (100) effectively operates the turbocharger (6) at low rates of exhaust gas flow which are associated with low engine operating speeds to mitigate lag in power delivery of the engine (1) before the engine speed rises to the required speed to operate the turbocharger (6) by the exhaust gasses.
[036] It should be imperative that the turbocharger assembly (100) and any other elements described in the above detailed description should not be considered as a limitation with respect to the figures. Rather, variation to such construction and method should be considered within the scope of the detailed description.
Equivalents:
[037] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
[038] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the

same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would Understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[039] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[040] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope.

Referral Numerals:

Reference Number Description
100 Turbocharger assembly
1 Engine
2 Driving member
3 Drive unit
4 Clutch
5 Shaft
6 Turbocharger
6a Compressor
6b Turbine
7 Auxiliary clutch
8 Gear arrangement
9 Exhaust manifold
10 Intake manifold

We Claim:
1. A turbocharger assembly (100) for an engine (1) of a vehicle, the turbocharger assembly
(100) having a compressor (6a) fluidly coupled to an intake manifold (10) of the engine (1)
and a turbine (6b) fluidly coupled to an exhaust manifold (9) of the engine (1), and
comprising:
a driving member (2) rotatably coupled to an output of the engine (1), the driving member (2) to be driven by the engine (1); and
a clutch (4) coupled to the driving member (2) to rotate along with the driving member (2), the clutch (4) is disposed on a shaft (5) that is coupled to the compressor (6a) and the turbine (6b), and is configured to:
engage the driving member (2) with the shaft (5) to transmit rotational motion of the driving member (2) to the shaft (5) for operating the compressor (6a) for a first speed of the engine (1); and
disengage the driving member (2) with the shaft (5) to allow operation of the compressor (6a) by the turbine (6b) for a second speed greater than the first speed of the engine (1).
2. The turbocharger assembly (100) as claimed in claim 1, wherein the driving member (2) and the clutch (4) are coupled together through a drive unit (3).
3. The turbocharger assembly (100) as claimed in claim 1, comprising a gear arrangement (8) disposed between the clutch (4) and the shaft (5).
4. The turbocharger assembly (100) as claimed in claim 1, wherein the driving member (2) is one of a pulley, a sprocket and a gear.
5. The turbocharger assembly (100) as claimed in claim 1, wherein the clutch (4) is a freewheel.
6. The turbocharger assembly (100) as claimed in claim 1, wherein the drive unit (3) is one of a belt, a chain and a gear drive.

7. A vehicle comprising:
an engine (1),
a turbocharger assembly (100) for the engine (1), the turbocharger assembly (100) having a compressor (6a) fluidly coupled to an intake manifold (10) of the engine (1) and a turbine (6b) fluidly coupled to an exhaust manifold (9) of the engine (1) and comprising:
a driving member (2) rotatably coupled to an output of the engine (1) to be driven by the engine (1); and
a clutch (4) coupled to the driving member (2) to rotate along with the driving member (2), wherein the clutch (4) is disposed on a shaft (5) that is coupled to the compressor (6a) and the turbine (6b), and wherein the clutch (4) is configured to:
engage the driving member (2) with the shaft (5) to transmit rotational motion of the driving member (2) to the shaft (5) for operating the compressor (6a) for a first speed of the engine (1); and
disengage the driving member (2) with the shaft (5) to allow operation of the compressor (6a) by the turbine (6b) for a second speed greater than the first speed of the engine (1), and
a transmission system connected to the engine (1), configured to transmit power from the engine (1) to wheels of the vehicle.
8. The vehicle as claimed in claim 7, wherein the driving member (2) and the clutch (4) are coupled together through a drive unit (3).
9. The vehicle as claimed in claim 7, comprising a gear arrangement (8) disposed between the clutch (4) and the shaft (5).
10. The vehicle as claimed in claim 7, wherein the clutch (4) is a freewheel.