A helicopter sled anti-skid device suitable for icy and snowy road surfaces and a helicopter

Abstract

This invention provides a helicopter skid anti-skid device and a helicopter suitable for icy and snowy surfaces, belonging to the field of helicopter landing gear design technology. In this device, one end of the brake skid is connected to the main skid via an actuation mechanism, and the bottom of the brake skid has an anti-skid layer. One end of the actuation mechanism is rotatably connected to the joint of the brake skid, and the other end is connected to the joint of the main skid. One end of the telescopic actuator is connected to the actuation mechanism and fixed to the joint of the main skid, and the other end is connected to a mounting bracket. An auxiliary wheel assembly is located at the tail of the brake skid. When the helicopter is skidding on the ice, the telescopic actuator extends under pressure, pushing the actuation mechanism. The actuation mechanism drives the brake skid to move relative to the main skid, retracting the auxiliary wheel assembly upwards and lowering the brake skid. The anti-skid layer of the brake skid contacts the ice surface, increasing the ground friction during skidding. This enables the helicopter to effectively stop and maintain differential braking function when skidding on icy and snowy surfaces.

Description

Technical Field

[0001] This invention belongs to the field of helicopter landing gear design technology, and particularly relates to a helicopter sled anti-skid device and helicopter suitable for icy and snowy surfaces. Background Technology

[0002] The biggest difference between helicopters that take off and land in extremely cold environments and conventional helicopters lies in the different operating environments. In extremely cold environments, most takeoff and landing sites are covered by ice and snow. When a helicopter lands and moves on an icy or snowy surface, the coefficient of friction between the wheels and the ice decreases exponentially. During the helicopter's ground taxiing phase, the contact torque between the wheels and the ground is less than the braking torque of the wheels, and the wheels tend to lock up. At this time, the helicopter is at risk of losing control of its ground movement, which poses a hidden danger to the safety of the helicopter braking on icy or snowy surfaces.

[0003] Meanwhile, differential braking, a common method for helicopter ground turning, involves braking one main landing gear wheel while leaving the other unbraked to create a difference in frictional torque. However, due to the extremely cold environment and the low contact coefficient between the wheels and icy surfaces, differential braking becomes difficult to achieve during ground turns. This effectively reduces the number of ground turning methods available for helicopters. Even with increased tire friction, traditional wheeled landing gear helicopters are prone to getting stuck in loose snow, failing to meet the requirements for effective braking and skidding correction. This significantly increases the risk of accidents when helicopters are maneuvering on icy surfaces. Summary of the Invention

[0004] To address the technical problem that existing wheeled landing gear helicopters cannot meet the requirements for effective braking and taxiing correction, this invention provides an anti-skid device that effectively increases the friction between the landing gear and the ground, thus providing an anti-skid effect for helicopters taxiing on ice surfaces. This enables the helicopter to effectively stop and maintain differential braking function on icy and snowy surfaces. When the helicopter needs directional correction, the brake skids are lowered, and the telescopic actuators mounted on the left and right landing gears of the helicopter output differential loads. This controls the differential friction between the two brake skids mounted on the left and right landing gears and the snow or ice surface, creating differential frictional resistance between the brake surfaces at the bottom of the two brake skids and the snow or ice surface. This generates the corrective torque required to correct the helicopter's taxiing direction, which is beneficial to the stability of the helicopter's taxiing direction. The technical solution is as follows:

[0005] In a first aspect, a helicopter skid anti-skid device suitable for icy and snowy surfaces is provided, comprising: a main skid 1, an actuation mechanism 3, a telescopic actuation cylinder 4, a brake skid 2, and an auxiliary wheel assembly 11. The main skid 1 is installed at the wheel axle position of the landing gear 5; one end of the brake skid 2 is connected to the main skid 1 via the actuation mechanism 3, and the bottom of the brake skid 2 is provided with an anti-skid layer; one end of the actuation mechanism 3 is rotatably connected to the joint of the brake skid 2, and the other end is connected to the joint of the main skid 1; one end of the telescopic actuation cylinder 4 is engaged with the actuation mechanism 3 and fixed to the joint of the main skid 1, and the other end is connected to the mounting bracket 6; the auxiliary wheel assembly 11 is located at the tail of the brake skid 2 to prevent the brake skid 2 from colliding with the ground and being damaged when the helicopter pitches up to land.

[0006] When the helicopter is gliding on the ice, the telescopic actuator 4 can extend under external pressure, pushing the actuator 3. The actuator 3 can drive the brake skid 2 to move relative to the main skid 1, retract the auxiliary wheel assembly 11 upward, and lower the brake skid 2. The anti-slip layer of the brake skid 2 contacts the ice surface, increasing the ground friction during gliding.

[0007] Optionally, the anti-slip layer is a textured, concave friction surface, which can increase the frictional resistance between the brake skid and the icy surface, providing the helicopter with the torque required for braking and correction.

[0008] Furthermore, the device also includes: a steel cable assembly 7, one end of which is connected to the body structure, and the other end is connected to the upper rocker arm of the connecting rod structure 8. The lower rocker arm of the connecting rod structure 8 is connected to the fixing pin 9. The fixing pin 9 is inserted into the mounting hole on the brake skid 2 and the mounting hole on the spring plate 10. A rotating shaft is provided below the mounting hole of the spring plate 10. The spring plate 10 is fixed on the brake skid 2, and the auxiliary wheel assembly 11 is mounted on the spring plate 10. Pulling the steel cable assembly 7 up causes the connecting rod structure 8 to drive the fixing pin 9 to disengage from the mounting hole of the spring plate 10. The spring plate 10 can rotate upward around the rotating shaft to achieve the purpose of retracting the auxiliary wheel assembly 11 upward, thus not hindering the lowering action of the brake skid.

[0009] Optionally, the auxiliary wheel assembly 11 includes: an auxiliary wheel support 12, an auxiliary wheel connector 13, a dust cover 14, and an auxiliary wheel 16.

[0010] The auxiliary wheel 16 is mounted on the bottom axle of the auxiliary wheel support 12, the auxiliary wheel joint 13 is mounted on the top mounting shaft of the auxiliary wheel support 12 and is fixedly connected to the spring plate 10, and the dust cover 14 is mounted above the auxiliary wheel joint 13.

[0011] Optionally, the auxiliary wheel joint 13 and the dust cover 14 are fixed to the auxiliary wheel support 12 by nuts 15.

[0012] Optionally, the steel cable assembly 7 includes: a steel rope 17, a steel rope fixing joint 18, a sleeve 19, a single-ear joint 20, a double-ear joint 21, and a fixing lock wire 22.

[0013] The steel rope 17, the steel rope fixing joint 18, and the single-ear joint 20 are interference-fitted; the single-ear joint 20 is connected to the upper rocker arm of the connecting rod structure 8.

[0014] The double-eared connector 21 is connected to the fuselage structure. The steel cable fixing connector 18 and the double-eared connector 21 are fastened to the sleeve 19 by threads. The double-eared connector 21 is fixed to the connector of the landing gear 5 by the double-eared connector mounting bolt group 23. By adjusting the thread engagement length of the steel cable fixing connector 18 and the double-eared connector 21, the installation length of the steel cable 17 can be changed to adjust the limit position of the skid. The single-eared connector 20 is fixed to the spring plate 10 by the single-eared connector mounting bolt group 24.

[0015] The steel rope fixing joint 18 and the sleeve 19 are provided with fixing lock wires 22 that can restrict the relative circumferential rotation of the steel rope fixing joint 18 relative to the sleeve 19.

[0016] Optionally, the locking wire 22 is composed of an outer locking wire support arm 26 and an inner locking wire support arm 27. The steel rope fixing joint 18 is provided with a steel rope fixing joint groove 28 for placing the inner locking wire support arm 27. The sleeve 19 is provided with a steel rope fixing locking wire mounting hole 25, and the arm hook of the outer locking wire support arm 26 is located in the steel rope fixing locking wire mounting hole 25.

[0017] In a second aspect, a helicopter is provided, including the helicopter ski anti-skid device for icy and snowy surfaces as described in any of the first aspects.

[0018] The beneficial effects of this invention are at least as follows:

[0019] 1. When the helicopter is gliding on the ice, the telescopic actuator cylinder extends under external pressure, pushing the actuation mechanism. The actuation mechanism drives the brake skid to move relative to the main skid, retracting the auxiliary wheel assembly upwards and lowering the brake skid. The anti-slip layer of the brake skid contacts the ice surface, increasing the ground friction during gliding. The bottom of the brake skid has an anti-slip layer, which effectively increases the friction between the helicopter and the icy surface during gliding.

[0020] 2. The anti-slip layer is a textured, concave friction surface. This friction surface increases the frictional resistance between the brake skid and the icy surface, providing the helicopter with the torque required for braking and correction.

[0021] 3. Simple structure and high reliability;

[0022] 4. The main skid, actuation mechanism, telescopic actuator, brake skid, etc. are all mechanically detachable and easy to replace;

[0023] 5. The steel rope and the steel rope fixing joint are fixed together by the external force of the machine to deform the steel rope material, making the steel rope and the steel rope fixing joint interference fit together, which is simple to fix and install;

[0024] 6. By adjusting the thread engagement length of the steel rope fixing joint and the double-ear joint, the installation length of the steel rope can be changed to adjust the limit position of the sled.

[0025] 7. The locking wire can restrict the relative circumferential rotation of the steel rope fixing joint with respect to the pipe sleeve, so that the steel rope will not fall out due to the loosening of the steel rope fixing joint.

[0026] 8. The entire steel rope device has few parts and a simple structure;

[0027] 9. The steel ropes in the cable assembly are more reliable than spring ropes. Attached Figure Description

[0028] Figure 1 This is a structural diagram of the helicopter sled anti-skid device of the present invention;

[0029] Figure 2 This is a schematic diagram of the brake skid being lowered according to the present invention;

[0030] Figure 3 This is a schematic diagram of the auxiliary wheel of the present invention;

[0031] Figure 4 This is a schematic diagram of the anti-slip layer on the brake skid plate of the present invention;

[0032] Figure 5 This is a diagram showing the composition of the steel cable assembly of the present invention;

[0033] Figure 6 This is a cross-sectional view of the steel cable assembly of the present invention;

[0034] Figure 7 This is a diagram showing the installation of the fixing screw in this invention;

[0035] Figure 8 This is a detailed diagram showing the installation of the fixing screw in this invention;

[0036] Figure 9 This is a schematic diagram of the installation steps for fixing the locking wire in this invention;

[0037] Figure 10 This is a detailed drawing of the present invention I; Figure 11 This is a schematic diagram of the groove for the steel rope fixing joint of the present invention.

[0038] Among them, 1-main skid, 2-brake skid, 3-actuator, 4-telescopic actuator, 5-landing gear, 6-mounting bracket, 7-steel cable assembly, 8-linkage structure, 9-fixing pin, 10-spring plate, 11-auxiliary wheel assembly, 12-auxiliary wheel support, 13-auxiliary wheel joint, 14-dust cover, 15-nut, 16-auxiliary wheel, 17-steel rope, 18-steel rope fixing joint, 19-tube sleeve, 20-single ear joint, 21-double ear joint, 22-fixing lock wire, 23-double ear joint mounting bolt group, 24-single ear joint mounting bolt group, 25-steel rope fixing lock wire mounting hole, 26-lock wire outer support arm, 27-lock wire inner support arm, 28-steel rope fixing joint groove. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0041] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited from each other.

[0042] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0043] Based on the design of sled-type landing gear and combined with the design of landing gear sled device, this invention provides a sled anti-slip device that can effectively solve the problem of runaway helicopters that may occur when using helicopters in polar environments, while maintaining the differential braking function of the helicopter.

[0044] Please see Figures 1-2An embodiment of the present invention provides a helicopter ski anti-skid device suitable for icy and snowy surfaces, comprising: a main skid 1, an actuation mechanism 3, a telescopic actuation cylinder 4, a brake skid 2, and an auxiliary wheel assembly 11. The main skid 1 is installed at the axle position of the landing gear 5; one end of the brake skid 2 is connected to the main skid 1 via the actuation mechanism 3, and the bottom of the brake skid 2 is provided with an anti-skid layer; one end of the actuation mechanism 3 is rotatably connected to the joint of the brake skid 2, and the other end is connected to the joint of the main skid 1; one end of the telescopic actuation cylinder 4 is engaged with the actuation mechanism 3 and fixed to the joint of the main skid 1, and the other end is connected to the mounting bracket 6; the auxiliary wheel assembly 11 is disposed at the tail of the brake skid 2 to prevent the brake skid 2 from colliding with the ground and being damaged when the helicopter pitches up to land; the main skid is installed at the axle position of the landing gear via a metal mounting bracket.

[0045] When the helicopter is gliding on the ice, the telescopic actuator 4 can extend under external pressure, pushing the actuator 3. The actuator 3 can drive the brake skid 2 to move relative to the main skid 1, retract the auxiliary wheel assembly 11 upward, and lower the brake skid 2. The anti-slip layer of the brake skid 2 contacts the ice surface, increasing the ground friction during gliding.

[0046] Please see Figure 4 The anti-slip layer is a textured, concave friction surface, which can increase the frictional resistance between the brake skid and the icy surface, providing the torque required for the helicopter to brake and correct its course.

[0047] In another embodiment, please refer to Figure 3 The device of the present invention further includes: a steel cable assembly 7, one end of which is connected to the body structure, and the other end is connected to the upper rocker arm of the connecting rod structure 8. The lower rocker arm of the connecting rod structure 8 is connected to the fixing pin 9. The fixing pin 9 is inserted into the mounting hole on the brake skid 2 and the mounting hole on the spring plate 10. A rotating shaft is provided below the mounting hole of the spring plate 10. The spring plate 10 is fixed on the brake skid 2. The auxiliary wheel assembly 11 is installed on the spring plate 10. Pulling the steel cable assembly 7 up causes the connecting rod structure 8 to drive the fixing pin 9 to disengage from the mounting hole of the spring plate 10. The spring plate 10 can rotate upward around the rotating shaft to achieve the purpose of retracting the auxiliary wheel assembly 11 upward, so as not to hinder the lowering action of the brake skid.

[0048] Please see Figure 3 The auxiliary wheel assembly 11 includes: an auxiliary wheel support 12, an auxiliary wheel connector 13, a dust cover 14, and an auxiliary wheel 16.

[0049] The auxiliary wheel 16 is mounted on the bottom axle of the auxiliary wheel support 12, the auxiliary wheel joint 13 is mounted on the top mounting shaft of the auxiliary wheel support 12 and is fixedly connected to the spring plate 10, and the dust cover 14 is mounted above the auxiliary wheel joint 13.

[0050] Please see Figure 3The auxiliary wheel joint 13 and the dust cover 14 are fixed to the auxiliary wheel support 12 by nuts 15.

[0051] To retract the auxiliary wheel assembly 11 upwards, the present invention provides a steel cable assembly 7, see [link to details]. Figure 5 and Figure 6 The steel cable assembly 7 includes: a steel rope 17, a steel rope fixing joint 18, a sleeve 19, a single-ear joint 20, a double-ear joint 21, and a fixing lock wire 22.

[0052] The steel rope 17, the steel rope fixing joint 18, and the single-ear joint 20 are interference-fitted; the single-ear joint 20 is connected to the upper rocker arm of the connecting rod structure 8.

[0053] The double-eared connector 21 is connected to the fuselage structure. The steel cable fixing connector 18 and the double-eared connector 21 are fastened to the sleeve 19 by threads. The double-eared connector 21 is fixed to the connector of the landing gear 5 by the double-eared connector mounting bolt group 23. By adjusting the thread engagement length of the steel cable fixing connector 18 and the double-eared connector 21, the installation length of the steel cable 17 can be changed to adjust the limit position of the skid. The single-eared connector 20 is fixed to the spring plate 10 by the single-eared connector mounting bolt group 24.

[0054] The steel rope fixing joint 18 and the sleeve 19 are provided with fixing lock wires 22 that can restrict the relative circumferential rotation of the steel rope fixing joint 18 relative to the sleeve 19.

[0055] Optionally, the steel rope 17 is deformed by external machine pressure, so that the steel rope 17 and the steel rope fixing joint 18 are interference-fitted together. Similarly, the steel rope 17 is deformed by external machine pressure, so that the steel rope 17 and the single ear joint 20 are interference-fitted together.

[0056] Please see Figure 5 , Figure 6 , Figure 7 and Figure 8 The fixing wire 22 consists of an outer locking arm 26 and an inner locking arm 27. The steel rope fixing joint 18 has a steel rope fixing joint groove 28 for placing the inner locking arm 27. The sleeve 19 has a steel rope fixing locking wire mounting hole 25, and the hook of the outer locking arm 26 is located in the steel rope fixing locking wire mounting hole 25. The fixing wire 22 can restrict the relative circumferential rotation of the steel rope fixing joint 18 relative to the sleeve 19. The specific restriction method is as follows: Figure 7 , Figure 8 and Figure 9 As shown, use torque to slightly pry open the outer support arm 26 and the inner support arm 27 of the locking wire 22, as follows: Figure 11 As shown, the inner support arm 27 is inserted into the steel rope fixing joint groove 28 of the steel rope fixing joint 18 installed inside the sleeve 19, as follows. Figure 10As shown, the end of the outer support arm 26 is inserted into the steel rope fixing lock wire mounting hole 25 on the sleeve 19. When the steel rope fixing joint 18 has a tendency to rotate relative to the sleeve 19, the fixing lock wire 22 will terminate this tendency by utilizing its structural deformation elastic force, thereby restricting the relative circumferential movement of the steel rope fixing joint 18 relative to the sleeve 19.

[0057] Another embodiment of the present invention also provides a helicopter, including the helicopter sled anti-skid device provided by the present invention for use on icy and snowy roads.

[0058] In one embodiment, the following analysis of the torque of the helicopter ski anti-skid device applicable to icy and snowy surfaces in this invention is conducted using a helicopter wheel braking system as an example, to illustrate the role of this invention in the helicopter braking process:

[0059] On normal land, assuming the coefficient of friction between the helicopter tires and the ground is approximately 0.5, the wheel radius is 280mm, and the vertical load on a single wheel is approximately 36000N, the frictional (coupling) torque that the wheels can provide to the ground can be calculated to be 5040N·m. The dynamic braking torque of the wheels is (3990~4080)N·m. Therefore, throughout the entire braking process of the helicopter, the frictional (coupling) force between the wheels and tires and the ground can ensure that the helicopter wheels will not slip during braking.

[0060] When a helicopter glides on ice, the coefficient of friction between the wheels and the ice decreases exponentially, generally not exceeding 0.1. As a result, the frictional torque (coupling) provided by the ground to the wheels becomes 1008 N·m, which is far less than the average braking torque of the helicopter wheels (3990~4080) N·m. Therefore, the helicopter may slip during normal braking. The brake skid designed in this invention has a friction coefficient of 0.8 between the brake surface and the ice surface. The actuation mechanism applies a vertical pressure of 10000 N to the brake skid, increasing the braking torque by 2240 N·m. This allows the helicopter's frictional torque to reach 3248 N·m, enabling the helicopter to basically meet the normal braking requirements on ice.

[0061] The above description merely illustrates embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Furthermore, any parts of the present invention not described in detail are conventional techniques.

Claims

1. A helicopter ski anti-skid device suitable for icy and snowy road surfaces, characterized in that, include: The main skid (1), brake skid (2), actuation mechanism (3), telescopic actuation cylinder (4), and auxiliary wheel assembly (11) are installed at the wheel axle position of the landing gear (5); one end of the brake skid (2) is connected to the main skid (1) through the actuation mechanism (3), and the bottom of the brake skid (2) is provided with an anti-slip layer; one end of the actuation mechanism (3) is rotatably connected to the joint of the brake skid (2), and the other end is connected to the joint of the main skid (1); one end of the telescopic actuation cylinder (4) is connected to the actuation mechanism (3) and fixed to the joint of the main skid (1), and the other end is connected to the mounting bracket (6); the auxiliary wheel assembly (11) is set at the tail of the brake skid (2); When the helicopter is gliding on the ice, the telescopic actuator (4) extends under external pressure, pushing the actuator (3). The actuator (3) drives the brake skid (2) to move relative to the main skid (1), retracting the auxiliary wheel assembly (11) upwards and lowering the brake skid (2). The anti-slip layer of the brake skid (2) contacts the ice surface, increasing the ground friction during the gliding process. The device further includes: a steel cable assembly (7), one end of which is connected to the body structure and the other end is connected to the upper rocker arm of the connecting rod structure (8). The lower rocker arm of the connecting rod structure (8) is connected to a fixing pin (9). The fixing pin (9) is inserted into the mounting hole on the brake skid (2) and the mounting hole of the spring plate (10). A rotating shaft is provided below the mounting hole of the spring plate (10). The spring plate (10) is fixed on the brake skid (2). The auxiliary wheel assembly (11) is installed on the spring plate (10). Pulling up the steel cable assembly (7) causes the connecting rod structure (8) to drive the fixing pin (9) to disengage from the mounting hole of the spring plate (10). The spring plate (10) rotates upward around the rotating shaft, and the auxiliary wheel assembly (11) is retracted upward.

2. The apparatus according to claim 1, characterized in that, The anti-slip layer is a textured, concave friction surface.

3. The apparatus according to claim 1, characterized in that, The auxiliary wheel assembly (11) includes: an auxiliary wheel support (12), an auxiliary wheel connector (13), a dust cover (14), and an auxiliary wheel (16). The auxiliary wheel (16) is installed on the bottom axle of the auxiliary wheel support (12), the auxiliary wheel joint (13) is installed on the top mounting shaft of the auxiliary wheel support (12) and is fixed to the spring plate (10), and the dust cover (14) is installed above the auxiliary wheel joint (13).

4. The apparatus according to claim 3, characterized in that, The auxiliary wheel joint (13) and dust cover (14) are fixed to the auxiliary wheel support (12) by nuts (15).

5. The apparatus according to claim 1, characterized in that, The steel cable assembly (7) includes: steel rope (17), steel rope fixing joint (18), tube sleeve (19), single ear joint (20), double ear joint (21), and fixing lock wire (22). The steel rope (17) and the steel rope fixing joint (18) and the single ear joint (20) are interference-fitted together; the single ear joint (20) is connected to the upper rocker arm of the connecting rod structure (8); The double-ear connector (21) is connected to the fuselage structure. The steel cable fixing connector (18) and the double-ear connector (21) are fastened to the sleeve (19) by threads. The double-ear connector (21) is fixed to the joint of the landing gear (5) by the double-ear connector mounting bolt group (23). The installation length of the steel cable (17) is changed by adjusting the thread engagement length of the steel cable fixing connector (18) and the double-ear connector (21). The single-ear connector (20) is fixed to the spring plate (10) by the single-ear connector mounting bolt group (24). The steel rope fixing joint (18) and the sleeve (19) are provided with fixing lock wires (22) that can restrict the relative circumferential rotation of the steel rope fixing joint (18) relative to the sleeve (19).

6. The apparatus according to claim 5, characterized in that, The locking wire (22) consists of an outer locking wire support arm (26) and an inner locking wire support arm (27). The steel rope fixing joint (18) is provided with a steel rope fixing joint groove (28) for placing the inner locking wire support arm (27). The sleeve (19) is provided with a steel rope fixing locking wire mounting hole (25). The hook of the outer locking wire support arm (26) is located in the steel rope fixing locking wire mounting hole (25).

7. A helicopter, characterized in that, Includes the anti-skid device for helicopter sleds applicable to icy and snowy surfaces as described in any one of claims 1 to 6.

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