The present disclosure relates to a pneumatic gear shift assistance device. Aspects of the invention relate to an apparatus comprising a pneumatic gear shift assistance device, and to a method of using a gear shift assistance device.
BACKGROUND
Heavy goods vehicle (HGV) drivers (such as lorry, truck drivers) with manual transmissions make many gear changes in a single day. Each time the driver makes a gear change they must exert a force to change the gear. HGVs have large and heavy gear boxes and transmission units that have a higher gear shifting force requirement than, for example, a manual gearbox in a car. The force for shifting lorry gear may be 5-15 kgf, however the shifting force necessary could reach to 50 kgf and further in particularly arduous conditions.
Shifting gears many times over the duration of a journey may place excess strain on the driver as they will be required to exert the large force every time they wish to shift up or down a gear. An example where gears are shifted multiple times is in city driving where the stop start nature of driving requires the driver to change gear multiple times.
Whilst an automatic transmission is able to shift gears automatically, they do not allow for the refined control a manual gear box affords the driver. Moreover, automatic gearboxes are expensive and may be less environmentally friendly than manual transmissions.
As such, there exists a need for a gear shift assist device to reduce the shifting force required to change gear in a heavy goods vehicle.

SUMMARY OF THE INVENTION
According to a first aspect of the invention a pneumatic gear shift assistance device is described. The pneumatic gear shift assistance device comprising: a housing; a piston; a control rod moveable along an axis; a valve with a first side fluidly sealed from a second side; a first poppet valve with a through bore and a second poppet valve. The piston is slidebly located in the housing; the first poppet valve, second poppet valve and valve are slideably located in the piston. The control rod is slideably received in the through bore. The valve is connected to an end of the control rod. The valve is disposed between the first poppet valve and the second poppet valve and arranged such that movement of the control rod and valve in a first direction along the axis actuates the first poppet valve independent of the second poppet valve and such that movement of the control rod and valve in a second direction along the axis actuates the second poppet valve independent of the first poppet valve.
The pneumatic gear shift assistance device has a number of advantages. The pneumatic gear shift device reduces the working force required to shift gears reducing strain on the operator. For example the strain on the operator may be reduced by almost 50 kgf using the present system. In the present invention the operator need only supply a relatively small force to actuate the pneumatic gear shift assist device, the rest of the force required to change gear is provided by pneumatic pressure.
Reducing the force required to shift the gears will allow a driver to operate the vehicle for a longer duration without undue burden. Further it will reduce the potential for injury due to muscle strain. Moreover using the present device will make a HGV easier to operate.
Advantageously the pneumatic fluid used to actuate the pneumatic gear shift assist device may be provided by a pressurised fluid source already present on a working vehicle. Working vehicles, such as lorries or other such HGVs generally have an air brake system supplied with pressurised air from an air compressor. The present pneumatic gear shift assist device may use pressurised air from said

air compressor to pressurise and actuate the device. As such an additional air compressor would not be required.
The first and second poppet valves may be actuated independently of each other. This means that should one of the two poppet valves fail in use the driver of the vehicle will still have pneumatic gear shift assist for half of the gears, e.g. odd gears (1, 3, 5, etc..) or even gears (R, 2, 4, etc.).
The valve is a spool valve. In other embodiments the valve may be a poppet valve.
The pneumatic gear shift assistance device further comprises an outlet unit with a vent connected to the piston. The second poppet valve has a through bore, the through bore being fluidly connected to the vent.
The vent is connected to the piston via the outlet unit such that the outlet unit and vent move with the piston. This also allows for a more compact arrangement.
The vent has a seal suitable for preventing ingress of water and dust. The seal advantageously prevents the ingress of contaminants that may damage the components within the device. The seal is preferably a flexible double diaphragm seal. In alternative embodiments the seal may be a single flexible diaphragm seal.
The vent further comprises a silencer suitable for silencing exhaust gas.
The valve further comprises a vent passage with a first vent bore on the second side, the vent passage and first vent bore are fluidly connected to the vent by through bore.
The vent passage allows the left and right sides of the valve to depressurise via the through bore in the second poppet valve. The exhaust arrangement of the present invention is space saving and compact and reduces the number of extra components and fluid lines required to operatively depressurise and vent the internal chambers of the pneumatic gear shift device.

The valve further comprises a second vent bore on the first side fluidly connected to the vent by the vent passage.
The second vent bore may be arranged perpendicular to the vent passage.
The valve defines a first throttle passage and a second throttle passage. The first throttle passage is located on the first side of valve and the second throttle passage is located on the second side of valve. The first throttle passage is fluidly connected to the second vent bore when the first poppet valve is unactuated; and wherein the second throttle passage is fluidly connected to the first vent bore when the second poppet valve is unactuated.
Advantageously the arrangement described allows the first throttle passage to only be depressurised with the first poppet valve is unactuated, the first throttle passage is prevented from depressurising when the second vent bore is actuated.
The valve has a flange. The flange is arranged to cover and seal the first vent bore when the second poppet valve is actuated thereby disconnecting the first throttle passage from the vent.
The valve has a further flange. The flange is arranged to cover and seal the second vent bore when the second poppet valve is actuated thereby disconnecting the second throttle passage from the vent.
The valve has a first throttle passage and a second throttle passage; the first throttle passage is located on the first side of valve and the second throttle passage is located on the second side of valve and wherein the piston further comprises a first bore, a second bore, a first volume and a second volume; the first bore connects the first throttle passage to the second volume and the second bore connects the second throttle passage to the first volume.

The first and second throttle passages connect to the second and first volumes of the piston respectively allowing the piston to move under a pneumatic force when either of the two volumes are pressurised. The other of the two volumes is depressurised. E.g. When the first poppet valve is actuated the first throttle passage and second volume is pressurised as the first throttle passage is disconnected from the vent. At the same time the second throttle passage and first volume are connected to the vent allowing the depressurisation of the second volume.
The control rod has a spring. The spring is biased to return the valve to a neutral position.
The biasing spring of the control rod is arranged such that it allows the valve to return to the unactuated position, thereby connecting both the first and second sides of the valve to the vent depressurising the first and second sides. Advantageously this happens automatically and without the need for driver input.
The control rod may further have a first collar and a second collar slidably disposed upon the control rod, wherein the spring is located between the first and second spring. The spring is biased to force the first and second collar away from each other.
The first and second collars and spring are located in a volume within the piston.
The first and second collars are slidably disposed within the piston volume.
The first and second collars assist in aligning the control rod and therefore the other components attached to the control rod. The collars assist in preventing misalignment of the pneumatic gear shift assist device.
The housing further comprises a pressurised fluid port operably connectable to the first throttle passage and the second throttle passage.

Advantageously the pressurised fluid port can be supplied via an air compressor located on a HGV. For example, the air compressor may also supply pressurised air to air brakes on said HGV.
The valve is co-axial with the control rod. Advantageously movement of the control rod means the valve is also moved as a direct result.
The valve is co-axial with the first poppet valve and the second poppet valve is co-axial with the valve.
The coaxial nature of the first poppet valve and the valve and the second poppet valve and the valve means that movement of the valve results in direct movement of the first or second poppet valve without the need for an intermediary component.
The first poppet valve has a biasing spring biasing the first poppet valve in an unactuated position. The biasing spring forces the first poppet valve into a normally closed position and reduces the chance of pressurised fluid leaking around the first poppet valve.
The second poppet valve has a biasing spring biasing the first poppet valve in an unactuated position. The biasing spring forces the second poppet valve into a normally closed position and reduces the chance of pressurised fluid leaking around the second poppet valve.
The piston has a bore, wherein the bore is operatively fluidly connected to the air inlet fitting suitable for supplying pressurised fluid to the first poppet valve and the second poppet valve. The bore advantageously supplies both of the poppet valves at the same time.
The piston may further comprise a channel, the channel extending perpendicular from the bore along such that the channel connects to the first and second poppet valves suitably for supplying fluid to said first and second poppet valves.

The piston further comprises a port, a first guide seal and a second guide seal. The first guide seal and second guide seal are located either side of the port.
The first and second guide seals are located on an outer surface of the piston. The first and second guide seals move with the piston. The first and second guide seals may be formed of a part of the piston.
The piston further comprises a first primary seal and a second primary seal. The first and second primary seals are located on the outer surface of the piston. The first and second primary seals are located either side of the port with the first guide seal and second guide seal located therebetween.
In a second aspect of the invention there is provided a method of actuating a pneumatic gear shift assistance device. The method comprising the steps of providing a pneumatic gear shift assistance device having: a housing; a piston; a control rod moveable along an axis; a valve with a first side, a second side; a first poppet valve with a through bore and a second poppet valve. The piston is slidably located in the housing. The first poppet valve, second poppet valve and valve are slidably located in the piston. The control rod is slidably received in the through bore. The valve is connected to an end of the control rod. The valve is disposed between the first poppet valve and the second poppet valve and arranged such that movement of the control rod and valve in a first direction along the axis actuates the first poppet valve and arranged such that movement of the control rod and valve in a second direction along the axis actuates the second poppet valve. The method comprising the further steps of: actuating the control rod; actuating the first poppet valve or the second poppet valve; supplying pressurised fluid to the first side of the valve of the valve via the actuated first poppet valve or supplying pressurised fluid to the second side of the valve via the actuated second poppet valve; moving the piston under pneumatic pressure; and the piston moving the control rod.

BRIEF DESCRIPTION OF THE DRAWINGS
One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a pneumatic gear shift assist device of the present invention.
Figure 2 is a close up view of the pneumatic gear shift assist device of Figure 1.
Figure 3 is a further close up view of the pneumatic gear shift assist device of Figure 1.
DETAILED DESCRIPTION
The present invention is a pneumatic gear shift assist device 20 which will be described with reference to Figures 1, 2 and 3. The pneumatic gear shift assist device 20 comprises: a housing 1; a piston 8; a control rod 7 moveable along an axis A; a valve 6 with a first side L, a second side R, a first throttle passage 11 and a second throttle passage 24; a first poppet valve 3 with a through bore 28 and a second poppet valve 22.
The housing 1 has an air inlet fitting 5. The air inlet fitting 5 is suitable for supplying a pressurised fluid to the device 20. The pressurised fluid is a pressurised air. The air may be clean dry air obtained from a compressor on a vehicle with the device 20 fitted thereto.
The piston 8 is slidebly received within the housing 1. The piston 8 has a port 15 that is fluidly connected to the air inlet fitting 5.
The piston 8 has a guide seal 31 located on one side of the piston in respect to a port 15, facing the housing 1 as shown in Figure 1. The piston 8 has a guide seal 32 located on the other side of the port 15 facing the housing 1 as shown in Figure 1. The guide seals 31 and 32 may be made from PTFE. The guide seals 31, 32 guide the piston 8 within the housing 1.

The guide seals 31, 32 may extend around the whole circumference of the piston 8.
The piston 8 has a primary seals 30 and 33 located on the piston 8 such that the guide seals 31, 32 are located between the primary seals 30, 33 as shown in Figure 1 and 2. The guide seals 31, 32 guide the piston 8 within the housing 1. The primary seals 30, 33 form an air tight seal with the housing 1 to prevent air from escaping a first volume 44 defined by the piston 8 and housing 1.
The primary seals 30, 33 may extend around the whole circumference of the piston 8.
The control rod 7 is connectable to a gear stick in a manner known to the skilled person, for example using a push or pull cable. This arrangement is not shown for reasons of clarity.
The control rod 7 is slideably received in the control rod guide 34. The piston rod guide defines a chamber 36 and a first collar 38 and a second collar 40. The first and second collars 38, 40 are slideably disposed at opposite sides of the chamber 36 as shown in Figure 1. The first and second collars 38, 40 define through bores through which the control rod 7 is fixedly supported such that movement of the control rod to the left in Figure 1 moves the second collar 40 also to the left. The first collar 38 is prevented from moving as the first collar 38 abuts against a wall of the chamber 36. Conversely moving the control rod 7 to the right in Figure 1 moves the first collar 38 also to the right. The second collar 40 is prevented from moving as the second collar 40 abuts against a wall of the chamber 36. The first and second collars 38, 40 are separated by a biased spring 18. The spring 18 is biased to force the first and second collars 38, 40 away from each other and into engagement with the chamber 36 walls such that the control rod 7 returns to its unactuated position shown in Figure 1.
The control rod 7 is moveable along axis A-A shown in Figure 1.

The piston 8 defines a valve housing 2 shown in Figure 1. The valve housing 2 contains the first and second poppet valves 3, 22 and the valve 6.
The piston 8 is connected a control rod guide 34 via the valve housing 2 at a connection point 80 shown in Figure 2. Movement of the piston 8 and valve housing 2 causes the control rod guide 34 to move and thus the control rod 7. Movement in one direction causes the control rod guide 34 to abut against the first collar 38 forcing the control rod 7 to move with the control rod guide 34. In the other direction the control rod guide 34 to abut the second collar 40 forcing the control rod 7 to move with the control rod guide 34.
The valve 6 is preferably a spool valve as shown in the Figures 1 and 2. Optionally the valve 6 may be another type of valve.
The valve housing 2 defines three chambers, a left chamber 60, a middle chamber 62 and a right chamber 64 shown in Figure 2. The left chamber 60 is operably connectable to the middle chamber 62 as will be described in further detail below. The right chamber 64 is operably connectable to the middle chamber 62 as will be described in further detail below.
The valve housing 2 defines an output unit 26. The output unit 26 has a vent 4 disposed at one end. The output unit 26 is coupled to move with the valve housing 2.
The vent 4 has a silencer. The silencer prevents loud degassing events from occurring.
The vent 4 has a seal to prevent ingress of water and dust. The seal prevents the ingress of contaminants that may damage the components within the device 20. The seal is preferably a double diaphragm seal. Optionally the seal may be a single diaphragm seal.
The valve housing 2 further defines a channel 17. The channel 17 is operatively connected to the air inlet fitting 5 via the piston 8 bore 15. The channel is fluidly

connected to the left chamber 60 via a first opening and the right chamber 64 via a second opening. The channel 17 supplies pressurised fluid from the air inlet fitting 5 via channel 17 to the left chamber 60 and right chamber 64.
The poppet valve 3 is located in the left chamber 60. The poppet valve 3 has a through bore 28. The through bore 28 is complementary to the control rod 7 which is received slidebly within the through bore 28. The through bore 28 may have an o-ring disposed within the through bore 28 to prevent fluid connection of the left chamber 60 and middle chamber 62 via the through bore 28 and also middle chamber 62 to the left chamber 60.
The poppet valve 3 has a valve seat 9 connected to a face of the poppet valve 3. The valve seat 9 forms a seal with a portion of the valve housing wall to seal the left chamber 60 from the middle chamber 62 (and therefore the throttle passage 11 and the left side of the valve L) when the poppet valve 3 is unactuated.
The poppet valve 3 has a poppet valve spring 13 disposed on the poppet valve as shown in Figure 1 and 2. The spring 13 is biased to return the poppet valve 3 to the unactuated position shown in Figure 1 and 2.
The poppet valve 22 is located in the right chamber 64.
The poppet valve 22 has a valve seat 25 connected to a face of the poppet valve 22. The valve seat 25 forms a seal with a portion of the valve housing wall to seal the right chamber 64 from the middle chamber 62 (second throttle passage 24 and the right side of the valve R) when the poppet valve 22 is unactuated.
The poppet valve 22 has a poppet valve spring 23 disposed on the poppet valve as shown in Figure 1 and 2. The spring 23 is biased to return the poppet valve 22 to the unactuated position shown in Figure 1 and 2.
The poppet valve 22 has a through bore 27. The through bore 27 operatively fluidly connects the middle chamber 62 and the vent 4 when the poppet valve 22

is unactuated. When the poppet valve 22 is actuated the middle chamber 62 and vent 4 are disconnected.
The first poppet valve 3 and second poppet valve 22 move independently of each other. Advantageously this means that should one of the two poppet valves 3, 22 fail then the operator may still have pneumatic gear assist for half of the gears. That is assist for odd gears (1, 3, 5, 7, etc..) or even gears plus reverse (R, 2, 4, 6, 8, etc.).
The spool valve 6 is connected to one end of the control rod 7 as shown in Figure 1 and 2 via connector 42. The connector 42 may be a threated connection or interference fit or welded or any other fit known in the art.
The spool valve 6 has a first side L on one side of the spool valve 6 and a second side R located on the opposite side of the spool valve 6 as shown in Figure 3.
The first side L and second side R are fluidly separated by at least one sealing ring 10 and portion 16 such that fluid cannot pass between the first side L and second side R along the spool valve 6. The portion 16 may have an o-ring 10 located either side.
The first side L defines the first throttle passage 11.
The second side R defines the second throttle passage 24.
The first throttle passage 11 is fluidly connected to a second volume 46 of the housing 1 via a bore 56. The first throttle passage 11 is operatively fluidly connected to the left chamber 60 when the poppet valve 3 is actuated.
The second throttle passage 24 is fluidly connected to a first volume 44 of the housing 1 via a bore 54. The second throttle passage 24 is operatively fluidly connected to the right chamber 64 when the poppet valve 22 is actuated.

The spool valve 6 has a vent passage 12. The vent passage 12 is disposed along the length of the spool valve 6 as shown in Figures 1 and 2. The vent passage 12 is connected to the vent 4 such that pressurised air exits the device 20 via the vent 4 to selectively depressurise volumes within the device 20.
The spool valve 6 has a vent bore 50 disposed on the first side L of the spool valve 6. The vent bore 50 is fluidly connected to the vent passage 12. The vent bore 50 is arranged perpendicular to the vent passage 12 through the spool valve 6. The vent bore 50 is operatively fluidly connected to the throttle passage 11.
The spool valve 6 has a vent bore 52 disposed on the second side R of the spool valve 6. The vent bore 52 is fluidly connected to the vent passage 12. The vent bore 52 is arranged so that is parallel to the vent passage 12. The vent bore 52 may be an orifice or aperture or opening in the spool valve 6 to throttle passage 24.
The spool valve 6 has a flange 70 located on the first side L of the spool valve 6. The flange 70 is engageable with the poppet valve 3 valve seat 9 such that pushing the flange 70 into the valve seat 9 actuates the poppet valve 3 thereby moving the valve seat 25 off housing wall.
The flange 70 is suitably disposed so that it forms a seal around the bore 28 when the spool valve 6 moves to engage the valve seat 9 and open the first poppet valve 3. This seal around bore 28 disconnects the throttle passage 11 from the vent bore 50 disposed in the spool valve 6.
The flange 70 may extend outwards from the spool valve 6 shaft. The flange 70 may be circular in cross-section.
The flange 70 may be uniform in cross-section from a surface that is engagable with the valve seat 9 to the back of the flange 70 that is opposite to the side engaging the valve seat 9. That is, the flange has uniform radius across its length. In other embodiments the cross-sectional area of the flange 70 may change linearly from an initial radius to a terminal radius. The initial radius may

be larger than the terminal radius or the terminal radius may be larger than the initial radius. The radius may be measured from axis A shown in Figure 1.
The flange 70 may have a lip extending from the flange 70. The lip has a smaller cross-section than the flange 70 such that the pressure applied by the operator of the device 20 when shifting is magnified by P = F/A. As the lip area is smaller than the flange 70 cross section the pressure is magnified meaning the poppet valve 3 can be actuated at a lower force.
The lip provides a good contact between the valve seat 9 such that further actuation of the valve 6 opens the valve seat 9 further connecting throttle passage 11 to the left chamber 60 whilst at the same time sealing the vent bore 50 from the throttle passage 11 and left chamber 60.
The spool valve 6 has a flange 72 located on the second side R of the spool valve 6 such that it encapsulates the vent bore 52. For example the vent bore 52 may be a hole or aperture entirely contained within the periphery of the flange. The flange 70 is engageable with the poppet valve 3 valve seat 9 such that pushing the flange 70 into the valve seat 9 actuates the poppet valve 3 thereby moving the valve seat 9 off housing wall.
The flange 72 may extend outwards from the spool valve 6 shaft. The flange 72 may be circular in cross-section.
The flange 72 may be uniform in cross-section from a surface that is engagable with the valve seat 25 to the back of the flange 72 that is opposite to the side engaging the valve seat 25. That is, the flange has uniform radius across its length. In other embodiments the cross-sectional area of the flange 72 may change linearly from an initial radius to a terminal radius. The initial radius may be larger than the terminal radius or the terminal radius may be larger than the initial radius.
The flange 72 is suitably disposed so that it forms a seal around vent bore 52 when the flange 72 engages the valve seat 25. The seal around vent bore 52

disengages when flange 72 disconnects the second throttle passage 24 from the vent 4.
The flange 72 may have a lip extending from the flange 72. The lip has a smaller cross-section than the flange 72 such that the pressure applied by the operator of the device 20 when shifting is magnified by P = F/A. As the lip area is smaller than the flange 72 cross section the pressure is magnified meaning the poppet valve 3 can be actuated at a lower force.
The lip provides a good contact between the valve seat 25 such that further actuation of the valve 6 opens the valve seat 25 further connecting throttle passage 24 and right chamber 64 whilst at the same time sealing the vent bore 52 from the throttle passage 24 and right chamber 64.
The pneumatic gear shift assist device 20 has three positions. A neutral positon (N) shown in Figure 1; a first position (spool valve 6 to left in Figure 1 and 2, e.g. for odd number gears 1, 3, 5); and a second position (spool valve 6 to the right in Figure 1 and 2, e.g. for even number gears 2, 4 and Reverse).
In the first position the spool valve 6 actuates the first poppet valve 3. This opens the first poppet valve 3.
In the second position the spool valve 6 actuates the second poppet valve 22. This opens the second poppet valve 22.
In the neutral position N neither the first poppet valve 3 nor second poppet valve 22 are actuated. In the middle position the vent bore 50 and vent bore 52 are open and connected to the middle chamber 62 allowing the middle chamber 62 to be vented via vent passage 12, bore 27 and vent 4. This also allows the first volume 44 to be fluidly connected to the vent 4 via the second throttle passage 24 and the second volume 46 to be connected to the vent 4 via the first throttle passage 11.

The operation of the pneumatic gear shift assistance device 20 will now be described with reference to Figures 1 and 2.
When starting the engine (or when the vehicle containing the pneumatic gear shift assistance device 20 is idling in Neutral, e.g. when parked) the pneumatic gear shift assistance device 20 is in the neutral position N shown in Figure 1 and 2.
In this position both the first volume 44 and the second volume 46 are connected to the vent 4 in the manner described above.
In this neutral N position the air inlet fitting 5 is fluidly connected to the left chamber 60 and right chamber 64 via the channel 17.
When the driver wishes to enter a gear (the first gear for example) the driver may depress a clutch pedal releasing a gear stick and control rod 7 for movement. The driver will then move the gear stick from the neutral gear to a first gear position. The force of this movement moves the control rod 7 towards the left of Figure 1. This in turn forces the spool valve 6 flange 70 into engagement with the poppet valve 3 seat 9.
The force is sufficient to overcome the spring force of the biasing spring 13—and any pneumatic pressure acting on the opposite side of the poppet valve 3 to the valve seat 9—such that the poppet valve 3 actuates. The actuation opens the left chamber 60 to the middle chamber 62 (and therefore the throttle passage 11 and the left side of the valve L) allowing pressurised air from the air inlet fitting 5 to enter the middle chamber on the left side L. At the same time the control rod 7 spring 18 is partially depressed moving collar 40 to the left at the same time.
The pressurised fluid then passes through the first throttle passage 11 and through the second bore 56 into the second volume 46. The pressurised fluid thus fills up the second volume 46 causing the piston 8 to move to the left.

The second volume 46 is prevented from depressurising or venting in this scenario as the flange 70 and seat 9 form a seal preventing fluid connection to the vent bore 50.
At the same time the right side R of the spool valve 6, the first volume 44, first bore 56 and second throttle passage 24 are vented or depressurised or remain depressurised as the bore 27 to the vent 4 remains open.
The pressure force in the second volume 46, P2, is therefore greater than the pressure force in the first volume 44, PL P2 > PL As a result the piston 8 moves to the left along with the valve housing 2 and the control rod 7. The movement of the piston 8 provides the pneumatic gear shift assist allowing the driver to complete the gear shift without straining.
The control rod guide 34 connected to the piston 8 moves to the left with the piston 8. This forces the control rod 7 to move with the control rod guide 34 and thus piston 8.
Once the gear is engaged it is retained by a detent structure (or a detent means). The detent structure is not shown in the Figures for reasons of clarity.
The piston 8 continues moving until the detent outside the housing 1 stops the device.
The control rod 7 spring 18 is biased to return the valve 6 into the unactuated position. The spring 18 returns to its unactuated shape moving collar 40 and thus control rod 7 with it. This process returns the poppet valve 3 to its unactuated position and uncovers the vent bore 50. As the vent bore 50 is uncovered the first throttle passage 11, second volume 46 and second bore 56 can vent.
The same process takes place with the second poppet valve 22 to move the control rod 7 to the right, for example from a first gear to a second gear.

The driver depresses the clutch and shifts the gear stick from 1st to 2nd gear. The action moves the control rod 7 to the right under the force the driver provides. The valve 6 flange 72 opens the poppet valve 22. The poppet valve 22 actuating connects the pressurised fluid contained in the right chamber 64 to the second throttle passage 24 and the right side of the valve R. Pressurised fluid then passes from the right chamber 64 through the second throttle passage 24 to first bore 56 and into the first volume 44. The first volume 44 then becomes pressurised forcing the piston 8 to move to the right.
The first volume 44 is prevented from depressurising or venting in this scenario as the flange 72 and seat 25 form a seal preventing fluid connection to the vent bore 52.
At the same time the left side L of the spool valve 6, the second volume 46, second bore 54 and first throttle passage 11 are vented or depressurised or remain depressurised as the bore 27 to the vent 4 remains open and connected to the second volume 46 via vent bore 50 and vent passage 12.
The pressure force in the second volume 46, P2, is therefore lower than the pressure force in the first volume 44, PL P1 > P2. As a result the piston 8 moves to the right along with the valve housing 2 and the control rod 7. The movement of the piston 8 provides the pneumatic gear shift assist allowing the driver to complete the gear shift without straining.
The control rod guide 34 connected to the piston 8 moves to the left with the piston 8. This forces the control rod 7 to move with the control rod guide 34 and thus piston 8.
Once the gear is engaged it is retained by a detent structure (or a detent means). The detent structure is not shown in the Figures for clarity.
The piston 8 continues moving until the detent outside the housing 1 stops the device.

The control rod 7 spring 18 is biased to return the valve 6 into the unactuated position. The spring 18 returns to its unactuated shape moving collar 38 and thus control rod 7 with it. This process returns the poppet valve 22 to its unactuated position and uncovers the vent bore 52. As the vent bore 52 is uncovered the second throttle passage 24, first volume 44 and first bore 54 can vent.
To move back to a neutral or forward gear position the driver may move the gear stick and the pneumatic gear shift assistance device 20 may move as described above.

I/We Claim:

1. A pneumatic gear shift assistance device (20) comprising:
a housing (1);
a piston (8);
a control rod (7) moveable along an axis (A);
a valve (6) with a first side (L) fluidly sealed from a second side (R)
a first poppet valve (3) with a through bore (28) and a second poppet valve (22);
wherein the piston (8) is slidebly located in the housing (1); the first poppet valve (3), the second poppet valve (22) and the valve (6) are slideably located in the piston (8);
the control rod (7) is slideably received in the through bore (28); the valve (6) is connected to an end of the control rod (7); and the valve (6) is disposed between the first poppet valve (3) and the second poppet valve (22) and arranged such that movement of the control rod (7) and valve (6) in a first direction along the axis (A) actuates the first poppet valve (3) independent of the second poppet valve (22) and such that movement of the control rod (7) and valve (6) in a second direction along the axis (A) actuates the second poppet valve (22) independent of the first poppet valve (3).
2. The pneumatic gear shift assistance device (20), of claim 1, wherein the pneumatic gear shift assistance device (20) further comprises an outlet unit (26) with a vent (4) connected to the piston (8); and wherein the second poppet valve (22) has a through bore (27), the through bore (27) being fluidly connected to the vent (4).
3. The pneumatic gear shift assistance device (20), of claim 2, wherein the valve (6) further comprises a vent passage (12) with a first vent bore (52) on the second side (R), the vent passage (12) and first vent bore (52) are fluidly connected to the vent (4) by through bore (27); and wherein the valve (6) further comprises a second vent bore (50) on the first side (L) fluidly connected to the vent (4) by vent passage (12).

4. The pneumatic gear shift assistance device (20) of claim 3, wherein the valve (6) defines a first throttle passage (11) and a second throttle passage (24); the first throttle passage (11) is located on the first side (L) and the second throttle passage (24) is located on the second side (R) of valve (6); and wherein the first throttle passage (11) is fluidly connected to the second vent bore (50) when the first poppet valve (3) is unactuated; and where in the second throttle passage (24) is fluidly connected to the first vent bore (52) when the second poppet valve (22) is unactuated.
5. The pneumatic gear shift assistance device of any preceding claim, wherein the valve (6) a first throttle passage (11) and a second throttle passage (24); the first throttle passage (11) is located on the first side (L) and the second throttle passage (24) is located on the second side (R);
wherein the piston (8) further comprises a first bore (54), a second bore (56), a first volume (44) and a second volume (46); and
wherein the first bore (54) connects the first throttle passage (11) to the second volume (46) and the second bore (56) connects the second throttle passage (24) to the first volume (46).
6. The pneumatic gear shift assistance device (20) of any preceding claim, wherein the control rod (7) has a spring (18); and wherein the spring (18) is biased to return the valve (6) to a neutral position (N).
7. The pneumatic gear shift assistance device (20) of any preceding claim, wherein the housing (1) further comprises a pressurised fluid port (5) operably connectable to the first throttle passage (11) and the second throttle passage (24).
8. The pneumatic gear shift assistance device (20) of any preceding claim, wherein the valve (6) is co-axial with the control rod; and/or wherein the valve (6) is co-axial with the first poppet valve (3) and the second poppet valve (22) is co-axial with the valve (6).

9. The pneumatic gear shift assistance device (20) of any preceding claim, wherein the first poppet valve (3) has a spring (13) biasing the first poppet valve in an unactuated position; and the second poppet valve (22) has a spring (23) biasing the first poppet valve in an unactuated position.
10. The pneumatic gear shift assistance device (20) of any preceding claim where the piston (8) further comprises a port (15), a first guide seal (31) and a second guide seal (32); and wherein the first guide seal (31) and second guide seal (32) are located either side of the port (15).