Hydraulic center pintle puller

Abstract

A method and apparatus for removing a center pintle from a machine bore is disclosed. The apparatus includes an extraction assembly and an elongated freezer assembly insert sized for insertion into the center pintle bore, forming a space between the freezer assembly insert and the wall of the center pintle bore. The space retains liquid nitrogen and allows the pintle to contract sufficiently to release the interference fit between the pintle and the machine bore, thereby allowing the pintle to be extracted from the bore. The apparatus and method conserve liquid nitrogen, reduce machine downtime, and are safer than known methods of center pintle removal.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 63 / 376,468, filed September 21, 2022, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to an apparatus and method for removing a center pintle from a large scale machine such as an electric rope shovel. [Background technology]

[0003] Large-scale machines are used as primary production equipment in many surface mining operations, such as oil sands mining. Rope shovels are one such machine. These shovels have a lower assembly, an upper assembly, and a front-end assembly. Figure 1, labeled "Prior Art," shows an exemplary rope shovel. The lower assembly, also known as the carbody or "base" (Figure 1A), contains the machine's propulsion drive system and crawler system, aiding in propulsion, repositioning, and movement during machine operation and providing a rigid and stable base for the upper and front-end assemblies. The upper assembly, or "frame" (Figure 1B), is supported on the base by a swivel mechanism that facilitates the frame's rotation about a substantially vertical axis when coupled to the base. The frame is composed of multiple decks, with the lower deck housing the hoist and swivel machinery and electronic control panel, and the upper deck housing the operator's seat. The front-end assembly (Figure 1C), which includes the boom, cloud machinery, dipper handle, dipper, and rope, swivels with the frame. The pivot mechanism may include a pintle assembly for pivotally coupling the frame and the base. The pintle assembly is disposed between the frame and the base and includes a hub in the lower assembly (base) and a shaft (center pintle) in the upper assembly (frame), which are generally aligned along a central axis D as shown in FIG. 1. The center pintle hub is fixed to the base and is configured to support and receive the lower end of the center pintle, the upper end of which is fixed to the upper assembly (frame). In operation, the pivot mechanism rotates the frame and shaft (center pintle) within the lower assembly (base). Summary of the Invention [Problem to be solved by the invention]

[0004] Electric rope shovels require regular maintenance, which includes preventive replacement of one or more parts that periodically fail. One of the parts that requires replacement is the center pintle. There are no tools specifically designed for removing the center pintle, and the procedure can take up to 72 hours. This procedure is dangerous because the maintenance personnel must enter a danger zone while lancing and shimming the pintle to loosen it, resulting in contact with liquid nitrogen.

[0005] The centre pintle is fitted to precise tolerances inside a bore in the frame with an interference fit. The centre pintle is hollow and, to remove it, is filled with liquid nitrogen to shrink the metal and release the interference fit. The centre pintle is then pulled out of the bore and a new, cooled pintle is inserted. Once the metal has returned to normal temperature, the centre pintle is securely fastened to the machine's frame.

[0006] What is needed is an apparatus and method that reduces center pintle maintenance downtime from the current 72 hours, is less expensive than current methods, and is safer for workers. [Means for solving the problem]

[0007] In one aspect described herein, there is provided an apparatus for removing a center pintle from a bore of a machine, the center pintle having a center pintle bore with a wall, the apparatus comprising: an extraction assembly for extracting the center pintle from the machine bore; an elongated freezer assembly insert sized for insertion into the center pintle bore to define an annular space therebetween and configured for connection to the center pintle; an annular space having an upper end and a lower end, the lower end being sealed to prevent leakage of water therefrom, and the upper end being configured to introduce water or liquid nitrogen into the annular space; a connector connected to the extraction assembly and the freezer assembly insert, wherein a pulling force by the extraction assembly on the connector extracts the freezer assembly insert, thereby causing the center pintle to exit the machine bore when connected to the freezer assembly insert; It is equipped with:

[0008] In one embodiment, the freezer assembly insert further comprises insulation that thermally insulates the connector from liquid nitrogen introduced into the annular space.

[0009] In one embodiment, the freezer assembly insert further comprises an elongated central bore and a wall surrounding the elongated central bore. In one embodiment, the connector is an elongated extension rod inserted into the elongated central bore.

[0010] In one embodiment, the wall is an insulating wall that thermally insulates the connector from liquid nitrogen introduced into the annular space. In one embodiment, the insulating wall is a sealed air space.

[0011] In one embodiment, the extraction assembly includes a hydraulic cylinder or an electric rod actuator.

[0012] In one embodiment, the device further comprises a spacer assembly supporting the device above and in axial alignment with the center pintle.

[0013] In another aspect, disclosed herein is a method of removing a center pintle from a bore of a machine, the method comprising: inserting a freezer assembly insert into the center bore of the center pintle to form an annular space between an outer wall of the freezer assembly insert and a wall of the center bore, the annular space being sealed at its bottom; connecting the freezer assembly insert to the center pintle; dispensing water into the annular space; dispensing liquid nitrogen into the annular space after dispensing water; contacting the liquid nitrogen with the wall of the pintle center bore until the center pintle shrinks sufficiently to release the interference fit between the center pintle and the machine bore; After the center pintle has retracted, pull the freezer assembly insert upward to remove the center pintle from the machine bore. Contains:

[0014] In one embodiment, pulling the freezer assembly insert upwardly includes pulling upwardly a connector connected to the freezer assembly insert.

[0015] In one embodiment, the method further includes thermally insulating the connector from the liquid nitrogen dispensed into the annular space.

[0016] In one embodiment, the step of connecting the freezer assembly insert to the center pintle includes positioning a pull-out ring under a lower end of the center pintle and connecting the pull-out ring to the freezer assembly insert.

[0017] In one embodiment, the method further includes the step of withdrawing the freezer assembly insert upwardly by actuating a hydraulic cylinder or an electric rod actuator. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a "Prior Art" diagram showing a side view of an exemplary rope shovel.

[0019] [Figure 2] FIG. 1 is an exploded view illustrating one embodiment of the components of a center pintle puller apparatus disclosed herein.

[0020] [Figure 3] 3 shows the components of the embodiment of FIG. 2 assembled onto the frame of a rope shovel.

[0021] [Figure 4A] 10 shows details of the means for connecting the retractor assembly to the spacer assembly.

[0022] [Figure 4B] 1 shows details of the leveling means.

[0023] [Figure 5] FIG. 10 is a cross-sectional view of the bottom of the extension rod connector and freezer assembly insert inserted and secured into the center pintle.

[0024] [Figure 6] 1 shows details of the connection between the piston rod of the hydraulic cylinder and the extension rod connector.

[0025] [Figure 7] FIG. 10 is a cross-sectional view of the top of the extension rod connector and freezer assembly insert inserted into the center pintle.

[0026] [Figure 8] FIG. 10 is a cross-sectional view of the top of the extension rod connector and freezer assembly insert inserted into the center pintle after the pintle has been withdrawn from the machine bore and secured to the spacer assembly.

[0027] [Figure 9] Detail showing the top of the extension rod connector with attached lifting eye inserted into the freezer assembly insert.

[0028] [Figure 10] FIG. 10 shows a detailed view of the extension rod connector and parts used to connect the bottom of the freezer assembly insert to the bottom of the center pintle.

[0029] [Figure 11] 1 shows the top of the center pintle after removal from the machine bore and after the freezer assembly insert has been removed, with the spacer assembly still secured in the keeper. DETAILED DESCRIPTION OF THE INVENTION

[0030] Disclosed herein are devices and methods for removing a center pintle from a machine that reduce the risks associated with center pintle removal compared to known devices and methods. The devices and / or methods reduce downtime for center pintle maintenance from 72 hours to approximately 12 hours, use significantly less liquid nitrogen than conventional methods, and are safer for workers because they are kept away from dangerous areas and the risk of exposure to liquid nitrogen is reduced, thereby improving efficiency.

[0031] The center pintle puller includes an extraction assembly, such as a hydraulic cylinder or electric rod actuator, that can extract the center pintle from a machine, such as a rope shovel (e.g., 7495 Electric Cable Shovel). With this device, the time required to remove the center pintle is approximately 12 hours, as lancing / shimming is no longer required, resulting in an approximately 83% reduction in downtime.

[0032] Additionally, by eliminating the need for shimming / lancing, liquid nitrogen usage can be reduced from one tank truck (e.g., approximately 2,000 gallons or more) to several tanks (e.g., approximately 135 gallons), resulting in cost savings of up to 92%.

[0033] The center pintle puller is assembled on-site and attached to the frame of an excavator or other machine for removing the center pintle. In an embodiment, a hydraulic cylinder extends to the bottom of the center pintle, to which a capture plate is attached. A freezer assembly insert is inserted into the center pintle bore, after which liquid nitrogen (or other suitable fluid cryogen) is introduced into the center pintle bore, causing the pintle to retract. The cylinder is hydraulically retracted, removing the center pintle from the upper and lower workpieces of the excavator or other machine.

[0034] The puller device disclosed herein includes an extraction assembly 1 for extracting the center pintle from the machine, a connector 6 for connecting the extraction assembly to the center pintle and / or freezer assembly insert, and a freezer assembly insert 9 for insertion into the center pintle bore. The assembled puller is placed over a spacer assembly 2, which positions the puller device above and in axial alignment with the center pintle and positions the puller device at a distance from the machine so that the center pintle can be fully extracted from the machine. "Connected to" or "attached to," as used herein, may refer to a direct or indirect connection or attachment.

[0035] Extraction assembly 1 provides the extraction force necessary to extract the center pintle from the machine bore. Connector 6 reversibly connects the center pintle to extraction assembly 1, such that the pulling force applied by extraction assembly 1 extracts the center pintle from the machine. Freezer assembly insert 9 occupies at least a portion of the volume of the center pintle bore, thereby reducing the amount of liquid nitrogen that enters the center pintle bore at one time compared to a bore without insert 9 therein. Finally, spacer assembly 2 positions the extraction assembly above the machine in line with the pintle, thereby ensuring sufficient linear distance for the pintle to be extracted from the machine bore when the extraction assembly is activated.

[0036] The preferred embodiment of the center pintle puller disclosed herein includes an extraction assembly 1, which is a hydraulic cylinder assembly, an elongated extension rod connector 6, an elongated freezer assembly insert 9, and a spacer assembly 2, which is a tube weld 2 (see FIG. 2). In this preferred embodiment, the elongated extension rod connector 6 is sized to fit inside the elongated bore 43 of the freezer assembly insert 9. The freezer assembly insert 9 is sized to fit inside the center bore 41 of the center pintle 40 (FIG. 11), leaving an annular space 45 between the outer wall 44 of the freezer assembly insert and the wall 42 of the center pintle bore 41 (FIG. 5). The hydraulic cylinder assembly 1 is sized to be spaced from the top of the machine and axially aligned above the center pintle for attachment to the spacer tube weld 2 (see FIG. 3).

[0037] In this embodiment, the hydraulic cylinder assembly 1 connects to the extension rod connector 6 and pulls on the extension rod connector 6, thereby withdrawing the center pintle from the bore in the machine frame and into the spacer assembly 2, as described below.

[0038] In this embodiment, the freezer assembly insert 9 includes a bore for insertion of the extension rod connector 6. The freezer assembly insert is configured to hold a volume of liquid nitrogen in an annular space 45 adjacent the center pintle, thereby cooling the pintle with liquid nitrogen until it shrinks sufficiently to allow removal from the frame. In one embodiment, the freezer assembly insert 9 is an elongated cylindrical tube having a bore 43 and a surrounding wall 44. In one embodiment, the wall 44 has an inner wall 46 and an outer wall 47, with a gap 48 between the two walls. The wall 44 is sized to form the annular space 45 between the outside of the wall 44 and the center pintle bore wall 42, thereby allowing a single or multiple successive doses of liquid nitrogen to be placed within the annular space to cool the pintle for removal. The wall 44 is sized to provide an inner bore 43 for insertion of the elongated extension rod 6. In embodiments having a double-walled wall 44, the gap between the outer wall 47 and the inner wall 46 may function, at least in part, to thermally insulate the extension rod 6 from the liquid nitrogen, reducing cooling of the rod compared to cooling of the pintle.

[0039] In this embodiment, the extension rod connector 6 connects with the cylinder rod and the center pintle 40 (indirectly via the pull-out ring 3) so that after the pintle contracts due to cooling with liquid nitrogen, the pulling force exerted by the cylinder rod on the extension rod 6 pulls the center pintle 40 out of the machine base and frame.

[0040] In an embodiment, the upper end of the extension rod connector 6 is connected to the cylinder rod using, for example, coupler plates 4, 5 (FIG. 6).

[0041] In an embodiment, the lower end of the extension rod connector 6 has a circumferential groove for receiving a shear collar 7 (FIG. 5). The shear collar 7 is positioned below the pull-out ring 3, which is positioned below the lower end of the center pintle 40, so that a force pulling upward on the extension rod connector 6 pulls the center pintle upward and out of the frame bore (see FIG. 5). In the embodiment shown herein, the pull-out ring 3 is connected to the bottom of the freezer assembly insert 6 and to the bottom of the center pintle. Thus, a force pulling upward on the extension rod connector 6 pulls both the center pintle 40 and the freezer assembly insert 9 upward.

[0042] O-rings 12, 13, and 14 seal the connection between the freezer assembly insert and the center pintle, thereby preventing any water introduced into the bottom of the annular space 45 from escaping from this space. This water freezes after liquid nitrogen is introduced into this space, thereby sealing the bottom of the annular space against liquid nitrogen.

[0043] Although illustrated herein as a hydraulic cylinder, any type of device or equipment capable of providing the necessary extraction force to extract the center pintle from the machine bore after the pintle has been sufficiently retracted by the liquid nitrogen is contemplated herein for extraction assembly 1. For example, an electric rod actuator may be used in place of the hydraulic cylinder.

[0044] Although illustrated herein as an elongated cylinder having a constant outer diameter and a constant inner diameter, the freezer assembly insert 9 may have an outer or inner diameter that varies along its length. Similarly, the thickness of the cavity 48 may vary along the length of the insert.

[0045] The embodiment of the freezer assembly insert 9 is shown as having two walls with a gap between them to at least partially thermally insulate the extension rod from the liquid nitrogen and reduce cooling of the rod. Other insulating means may be used, such as placing a substance other than air between the double walls, creating a vacuum between the double walls, or constructing the walls from insulating material.

[0046] Although the extension rod connector 6 and the freezer assembly insert 9 are illustrated herein as being two separate pieces, they may also be of unitary construction.

[0047] Also disclosed is a method for removing a center pintle from a machine bore, the method comprising: inserting the freezer assembly insert into the bore of the center pintle so as to form an annular space between an outer wall of the freezer assembly insert and a wall of the bore, the annular space being sealed at the bottom, and in a preferred embodiment, the freezer assembly insert is an elongated structure that forms an elongated annular space between the freezer insert and a wall of the bore of the center pintle; connecting a freezer assembly insert to the center pintle, in a preferred embodiment, the freezer assembly insert has its bottom secured to the bottom of the center pintle such that the annular space extends to the bottom of the center pintle; dispensing water into the bottom of the annular space, the amount of water dispensed being sufficient to freeze at the bottom of the annular space when liquid nitrogen is added, thereby preventing the liquid nitrogen from leaking out of the annular space; dispensing liquid nitrogen into the annular space above the water; contacting the walls of the center pintle bore with liquid nitrogen until the center pintle shrinks sufficiently to release the interference fit between the pintle and the bore of the machine, which liquid nitrogen may be added in aliquots to the annular space to achieve sufficient shrinkage to allow removal of the center pintle; After the center pintle has contracted (shrinked), the freezer assembly insert is pulled upward to remove the center pintle from the frame. In an embodiment, the freezer assembly insert includes a bore for receiving the extension rod, and the step of pulling the freezer assembly insert upward includes pulling the extension rod upward, thereby pulling the freezer assembly insert and the center pintle upward. Includes.

[0048] Having described the main components and method of use of the center pintle puller, an exemplary embodiment of the use of this puller to remove a center pintle from a rope shovel will now be described in detail with reference to the figures.

[0049] Cylinder preparation, operation, and power shutdown The cylinder stand 8 is installed on a level, leveled surface. This stand is used for assembling and disassembling the puller when removing it from the shovel.

[0050] The cylinder uses two counterbalance valves to hold the load in case a hydraulic hose or fitting ruptures and the cylinder loses pressure. The table below shows the relationship between load-induced pressure and power pack pump pressure. Gauge pressure at the pump will read 600 to 1200 psi when the cylinder is cycling with no load.

[0051] [Table 1]

[0052] General preparation for removing the center pintle The upper and lower coupler plates 4, 5 (Figure 2) are threaded onto the cylinder rod and extension rod 6 of the cylinder assembly 1, respectively. The couplers are threaded until they are fully seated on the shoulders of the rods. A low-strength locking compound, such as Loctite ThreadLocker Blue 24®, may be used on the last few threads.

[0053] The lifting fixture 10 is attached to the freezer assembly insert 9 using cap screws 19. The pull ring 3 is positioned below the track frame, aligned with the center pintle. The pedestal jack bolts 25, clevis pin 16, and keepers 11 and 26 are provided.

[0054] Split collar 28 is attached to extension rod 6 using cap screws 20 and tightened to a predetermined torque (e.g., 49 ft-lb or 66 Nm). Collar 28 acts as a locating shoulder to prevent extension rod 6 from falling through pull-out ring 3 as it is lowered through the pull-out ring.

[0055] Removing the center pintle Cylinder assembly 1 is connected to the top of spacer tube 2 and secured with keeper 11, nut 15, and locking pin 22 (Figs. 3 and 4A). Lift freezer assembly insert 9 into place, install pull ring 3 onto freezer assembly insert, and install O-rings 13, 14 and cap screw 8, tightening to a torque of 49 ft-lb (66 Nm).

[0056] Lift the freezer assembly insert 9 and attach the pull ring 3 to the center pintle with cap screws 21 and O-ring 12. Remove the lifting fixture 10. The extension rod 6 is lowered through the freezer assembly insert 9 and the shear collar 7 is attached to the rod 6 with cap screws 20 torqued to 250 ft-lb (338 Nm).

[0057] The assembled cylinder 1 and spacer tube 2 are lifted into position on the excavator's rotating bed (upper frame) (Figure 3). This diagram shows the preferred orientation of the work platform. The assembly is leveled with the pedestal jack bolts 25. The hydraulic system is bled and the hydraulic lines from the hydraulic power pack are attached to the cylinder. The cylinder rod is cycled 3 to 5 times under no load while monitoring the hydraulic fluid level in the power pack reservoir. Depending on the load-hold setting of the counterbalance valve, the power pack pressure gauge should register 600 to 1200 psi while cycling the cylinder rod under no load.

[0058] Install coupler bolts 17 into the upper and lower coupler plates 4 and 5 and tighten to a torque of 250 ft-lb (338 Nm). A low torque is used to increase the tensile strength of the cap screws. Pour 1 to 3 gallons of water into the annular space 45 between the pintle and the freezer. The water acts as an ice dam to seal in the liquid nitrogen and protect the O-ring seal. The assembly is checked to ensure there are no leaks.

[0059] The annular space 45 ("cavity") between the freezer and the pintle is filled with liquid nitrogen. After a suitable soak time, a hydraulic cylinder is actuated to remove the center pintle. The center pintle is secured in a bore in the machine frame with an interference (shrink) fit. Heat shrink is used to remove the center pintle from the frame bore. The proper soak time is one that results in sufficient shrinkage of the center pintle so that it can be removed from the frame bore. Additional liquid nitrogen may need to be added to the annular space to achieve this shrinkage.

[0060] Once the pintle has passed through the frame bore, it is secured in place using a keeper 26. The keeper is hand-tightened until full contact is achieved. The keeper is designed to slide under the pintle shoulder and uses an undercut radius to lock the pintle in place (as shown in Figure 8).

[0061] Disconnect the hydraulic lines from the cylinder. Rigging is attached to the cylinder to lift the assembly from the frame.

[0062] Pintle disassembly procedure The cylinder and spacer tube are placed on a cylinder stand 8 and secured with pins 16 and locking pins. The pull-out ring 3 is textured to allow access to the bolts.

[0063] Remove coupler bolts 17 and attach a crane / hoist to the cylinder hoist ring. The cylinder assembly is disassembled from the spacer tube by removing keepers 11, nuts 15 and locking pins 22 and the cylinder is hoisted into place.

[0064] A lifting eye is attached to the extension rod 6 (see Figure 9) and attached to a crane / hoist. The collar 7 is removed from the extension rod 6 and the extension rod 6 is hoisted into place. The lifting fixture 10 is attached to the freezer assembly insert 9 using cap screws 19 torqued to 140 in-lbs (15.8 Nm).

[0065] Any remaining liquid nitrogen in the annulus 45 is allowed to evaporate. A hoist is attached to the lifting fixture 10 and tensioned, and the bolts 21 are removed from the pull-out ring 3. The cribbing is removed, the pull-out ring 3 is lowered onto the platform, and the cap screws 18 are removed. The freezer assembly insert is lifted from the spacer assembly.

[0066] Now we are ready to remove the center pintle. Attach the lifting jig and hoist to the center pintle and tension the hoist until the keeper 26 rotates freely by hand. The keeper 26 is not threaded in until the pintle can be removed.

[0067] Although the present apparatus and method have been described in relation to its use for removing a center pintle from a rope shovel, it will be appreciated that the present method and apparatus may also be used with other machines having a center pintle.

[0068] While the present apparatus and method have been described in conjunction with the disclosed embodiments, which are specifically described, it should be understood that this is by way of example and that it is not intended that the disclosure be limited to these embodiments. On the contrary, the present disclosure is intended to cover alternatives, modifications, and equivalents that will become apparent to those skilled in the art in light of the present disclosure.

Claims

1. 1. Apparatus for removing a center pintle from a bore of a machine, the center pintle having a center pintle bore with a wall; a) an extraction assembly for extracting the center pintle from the bore of the machine; b) an elongated freezer assembly insert sized for insertion into the center pintle, forming an annular space between the freezer assembly insert and the wall of the center pintle bore, the freezer assembly insert configured to connect to the center pintle; c) the annular space having an upper end and a lower end, the lower end being sealed to prevent water leakage and the upper end being configured to introduce water or liquid nitrogen into the annular space; d) a connector connected to the extraction assembly and the freezer assembly insert, wherein a pulling force of the extraction assembly on the connector pulls the freezer assembly insert, thereby extracting the center pintle from the bore of the machine when connected to the freezer assembly insert; A device comprising:

2. the freezer assembly insert further comprises insulation for thermally insulating the connector from liquid nitrogen introduced into the annular space.

10. The apparatus of claim 1.

3. the freezer assembly insert further comprising an elongated center bore and a wall surrounding the elongated center bore; 10. The apparatus of claim 1.

4. the connector is an elongated extension rod inserted into the elongated center bore; 4. The apparatus of claim 3.

5. the wall is a thermal insulating wall that thermally insulates the connector from liquid nitrogen introduced into the annular space.

5. The device according to claim 3 or 4.

6. The insulating wall has a sealed air space.

6. The apparatus of claim 5.

7. the extraction assembly includes a hydraulic cylinder or an electric rod actuator; 7. An apparatus according to any one of claims 1 to 6.

8. a spacer assembly supporting the device above and in axial alignment with the center pintle; 8. Apparatus according to any one of claims 1 to 7.

9. 1. A method of removing a center pintle from a bore of a machine, comprising: a) inserting a freezer assembly insert into the center bore of the center pintle so as to form an annular space between an outer wall of the freezer assembly insert and a wall of the center bore; b) connecting the freezer assembly insert to the center pintle; c) dispensing water into said annular space; d) dispensing liquid nitrogen into the annular space after dispensing the water; e) contacting the liquid nitrogen with the wall of the center bore of the pintle until the center pintle contracts sufficiently to release the interference fit between the center pintle and the bore of the machine; f) after the center pintle has retracted, pulling the freezer assembly insert upward to withdraw the center pintle from the bore of the machine. A method comprising:

10. Pulling the freezer assembly insert upward includes pulling a connector connected to the freezer assembly insert upward.

10. The method of claim 9.

11. further comprising the step of thermally insulating the connector from the liquid nitrogen dispensed into the annular space. The method of claim 10.

12. the step of connecting the freezer assembly insert to the center pintle includes disposing a pull-out ring under a lower end of the center pintle and connecting the pull-out ring to the freezer assembly insert.

10. The method of claim 9.

13. the step of pulling the freezer assembly insert upward is performed by actuating a hydraulic cylinder or an electric rod actuator.

13. The method according to any one of claims 9 to 12.

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