GB2449975A

GB2449975A - Tamper resistant cap for a fire hydrant

Info

Publication number: GB2449975A
Application number: GB0810029A
Authority: GB
Inventors: Daniel Verrall
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-06-02
Filing date: 2008-06-02
Publication date: 2008-12-10
Anticipated expiration: 2028-06-02
Also published as: GB0922312D0; GB2462784B; GB0810029D0; GB0710568D0; GB2449975B; WO2008149068A1; GB2462784A

Abstract

The present application relates to a tamper resistant cap (1). The cap (1) has a cover (5) for fitting over an opening, the cover (5) being adapted to be removed from the opening by rotation about a removal axis (A). A drive means (9) is positioned on the cover (5) offset from the removal axis (A) and the cover (5) may be rotated about the removal axis (A) by the drive means (9) to remove the cover (5) from the opening. A sleeve (7) surrounds the drive means (9) at least circumferentially with respect to the removal axis (A), the sleeve (7) being freely rotatable with respect to the cover (5). The cap (1) may be a secure cap for a fire hydrant (3, fig 3). The cover may have a screw thread or bayonet fitting, a tool (33, fig 5) is provided to engage the drive means to remove or install the cap. The sleeve may be mounted on a ball bearing (19) provided between the cover and the sleeve.

Description

TAMPER RESISTANT CAP

This invention relates to both a secure fire hydrant cap (SFHC) and a fire hydrant cap removal tool (FHCRT).

There are approximately 3 million underground fire hydrants within the UK The fire hydrants are used primarily for the fire brigade to obtain water to carry out their fire fighting duties, but can also be used as a washout for the water companies A typical fire hydrant is illustrated in Figure 3 Unfortunately, some of these fire hydrants have been subjected to sabotage For example, the cap may be removed from the hydrant without specialist equipment Significantly, the fire hydrant's bolted outlet and cap may be removed This in effect renders the hydrant operationally unavailable.

The present invention, at least in preferred embodiments, attempts to overcome or ameliorate the probems associated with known fire hydrants Viewed from a first aspect, the present invention relates to a tamper resistant cap comprising a cover for fitting over an opening, the cover being adapted to be removed from the opening by rotation about a removal axis; drive means positioned on the cover offset from the removal axis, by which drive means the cover may be rotated about the removal axis to remove the cover from the opening, and a sleeve surrounding the drive means at least circumferentially with respect to the removal axis, the sleeve being freely rotatable with respect to the cover. The sleeve is freely rotatable relative to the cover and, therefore, an individual attempting to remove the cap will rotate the sleeve without removing the cover. Thus, the present invention may help prevent tampering with the cover, such as unauthorised removal of the cover The sleeve may form a guard around the drive means and may limit access to the drive means. The sleeve is preferably open at one end to allow access to the top of the cover and to the drive means The cover may be mounted over the opening using any suitable mechanical fastening means Preferably, however, the cover has a screw thread or bayonet fitting for engaging with the opening A screw thread or one or more projections may be associated with the opening for mounting the cap The drive means could be a recess formed in the cover A recess may be provided in the cover for receiving a drive member for fitting/removing the cap A locating device may be provided to locate the drive member in said recess. For example, the tool may engage the sleeve or a flange provided on the sleeve to retain the drive member in position Preferably, the drive means is a member coupled to the cover The drive means is preferably a member mounted on the cover. Preferably, the member extends along a drive axis offset from and substantially parallel to the removal axis The offset between the drive axis and the removal axis may be less than or equal to 10mm, 15mm or 20mm The member is preferably rotatable about the drive axis The drive means may be a cone centred on the drive axis Preferably the tip of the cone is oriented away from the cap Alternatively, the drive means may be a bulb, dome, hemisphere or sphere The drive means is preferably mounted on or coupled to the cover A drive pin may extend from the drive means to the cover The drive means preferably covers the drive pin to restrict or prevent access to the drive pin The sleeve is preferably mounted on a bearing to allow free rotation of the sleeve relative to the cover Preferably, a bearing is provided between the cover and the sleeve The bearing is preferably enclosed by said sleeve.

The sleeve may be freely rotatable in both directions (I e clockwise and anti-clockwise). Alternatively, the sleeve may be freely rotatable in only one direction The sleeve may be freely rotatable in a first direction and prevented from rotating relative to the cover in the opposite direction The sleeve may be freely rotatable in the direction in which the cover is rotated to remove it, and rotation of the sleeve relative to the cover in the opposite direction may be limited or prevented Thus, the cap may be rotated via the sleeve to screw the cover into position, whereas rotation of the sleeve in the opposite direction does not rotate the cover If the cover has a right-hand thread, the sleeve may be freely rotatable in an anti-clockwise direction (the direction in which the cover is rotated to remove it) and rotation of the sleeve in a clockwise direction may be prevented Conversely, if the cover has a left-hand thread, the sleeve may be freely rotatable in a clockwise direction and rotation of the sleeve in an anticlockwise direction may be prevented A mechanism, such as a clutch or a ratchet and paw!, may be provided to allow rotation of the sleeve in only one direction The sleeve preferably extends above the height of the drive means Preferably, the sleeve surrounds both the cover and the drive means. The cover may have a sidewall extending around the opening. Preferably, the sleeve extends around the sidewall of the cover and may project beyond a bottom edge of the cover Thus, the sleeve may encapsulate the sidewall of the cover and restrict or limit access The cap described herein may be used on a range of inlets and/or outlets Preferably, however, the cap is a fire hydrant cap for covering the outlet of a fire hydrant The present application also extends to a tool for opening a tamper resistant cap of the type described herein Viewed from a yet further aspect, the present invention relates to a tool for removing a tamper resistant cap, the tool comprising a locating member for locating the tool on the tamper resistant cap and engagement means for drivingly engaging a drive means provided on the cap The engagement means preferably engages the drive means and enables the cap to be rotated The cap may have a rotatable anti-tampering sleeve of the type described herein The locating member may be located on the cap by said sleeve. The engagement means preferably comprises a recess for receiving the drive means provided on the cap The recess may be cylindrical, spherical or conical in shape Viewed from a still further aspect, the present invention relates to a tamper resistant cap comprising a cover for fitting over an opening, drive means for removing the cover, and a sleeve surrounding the drive means and/or the cover at least circumferentially, the sleeve being freely rotatable with respect to the cover Viewed from a further aspect, the present invention relates to a secure fire hydrant cap for securing the outlet of a fire hydrant, the cap comprising a first rotating part, a second rotating part and a female cap screw, the first rotating part being an outer locating tube for shielding the female cap screw, the outer locating tube being rotatable relative to the female cap screw; and the second rotating part being an inner locating bulb for securing an inner locating pin.

The present invention also relates to a fire hydrant cap removal tool for removing a secure fire hydrant cap having first and second rotatable parts, the tool being adapted to fit over both the first and second parts of the secure fire hydrant cap.

At least in preferred embodiments the present invention proposes a secure fire hydrant cap that may be fitted to a range of fire hydrants ensuring the security of the outlet. This secure fire hydrant cap will preferably be manufactured with two moving parts using bearings Preferably an outer locating tube and an inner location bulb These two moving parts, along with the shape and design of the inner location bulb may help to ensure that the cap is securely fitted until removed by a fire hydrant removal tool There are two main drivers behind this design and they are as follows.

1) it should preferably be quick and efficient to remove the cap to access the outlet in emergency situations (i e in the event of a fire).

2) Without appropriate equipment, such as a dedicated removal tool, it should preferably be extremely difficult and time consuming to remove the cap to access the outlet to help prevent misuse Preferably, the fire hydrants will have no exposed nuts or bolts on the outlet If this is not the case an additional shielding may be provided around these items Alternatively, shear nuts or bolts may be used whereby a portion of the nut or bolt shears off to prevent tampering Viewed from a further aspect, the present invention relates to a secure fire hydrant cap that secures the outlet of a fire hydrant The secure fire hydrant cap preferably has two rotating parts The first rotating part is preferably an outer locating tube which shields a female cap screw. Preferably, the outer locating tube has no locating points to latch onto with a tool.

The second rotating part is preferably an inner locating bulb which secures the inner locating pin The inner locating bulb is preferably designed so that there are no locating points to latch onto with a tool The inner locating bulb preferably rotates freely around its axis such that, if a tool is located over the inner locating bulb in isolation and then subjected to sideways pressure, the tool would slip off of the inner locating bulb Preferred embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying Figures, in which Figure 1 shows a secure fire hydrant cap according to a first embodiment of the invention, Figure 2A shows the internal mechanism of the secure fire hydrant cap, Figure 2B shows a cross section through a modified version of the secure fire hydrant cap according to the first embodiment; Figure 3 shows the existing underground fire hydrant and cap, Figure 4 shows the existing underground fire hydrant with both the secure fire hydrant cap according to the invention plus the additional shield around the nuts and bolts fitted, Figure 5 shows a fire hydrant removal tool that is required to remove the secure fire hydrant cap (Inside View), Figure 6 shows the fire hydrant removal tool that is required to remove the secure fire hydrant cap (Top View), Figure 7 is a cross-section showing the internal mechanism of the fire hydrant removal tool that is required to remove the secure fire hydrant cap, Figure 8 shows a transverse cross-section of a tamper resistant cap and an associated tool in accordance with a second embodiment of the present invention, Figure 9 shows a plan view of the tamper resistant cap of Figure 8; Figure 10 shows the tool for fitting and removing the cap according to the second embodiment of the invention, and Figure 11 shows a handle for rotating the tool shown in Figure 10 A secure fire hydrant cap 1 in accordance with a first embodiment of the present invention is shown in Figures 1 and 2A The cap 1 is suitable for mounting on a standard fire hydrant 3 to seal the hydrant outlet (not shown) and to help prevent tampering The cap 1 comprises a cover 5 for closing the hydrant 3, a rotatable sleeve 7 and a drive means in the form of a bulb 9 The cover 5 is a female cap screw having a cylindrical sidewall 11 and an end plate 13 A female thread 15 is provided on the interior of the sidewall 11 for cooperating with a male thread (not shown) provided on the exterior of the fire hydrant 3 The cover 5 is rotated about a first axis A to mount the cap 1 on the fire hydrant 3 The end plate 13 abuts the hydrant outlet and forms a seal preventing the egress of water To remove the cap 1 the cover 5 is rotated about the first axis A, herein referred to as the removal axis An upper plate 17 is mounted on the cover 13 A large first bearing 19 is mounted between the cover 1 3 and the upper plate 17 to allow the sleeve 7 to rotate independently of the cover 5 Thus, the sleeve 7 can be rotated freely without moving the cover 5 An inner off-centre location pin 21 and a locking pin 23 are provided for mounting the upper plate 17 on the cover 13 The inner off-centre location pin 21 transfers drive forces to the cover 13 and is referred to as a drive pin 21 herein The drive pin 21 extends through the cover 13 and the upper plate 17 and projects upwardly from a top surface of the upper plate 17 The drive pin 21 is welded to the cover 13 at its lower end to secure it in position The locking pin 23 is an interference fit in blind holes formed in the cover 1 3 and the upper plate 17 The drive pin 21 and the locking pin 23 prevent the upper plate 17 rotating with respect to the cover 13 The drive pin 21 defines a second axis B offset from and parallel to the first axis A The offset between the first and second axes A, B in the present embodiment is 15mm The bulb 9 is rotatably mounted on the upper end of the drive pin 21 and a nut 25 is provided to secure the bulb 9 in position. A small second bearing 27 is provided between the bulb 9 and the drive pin 19 to ensure that the bulb 19 can rotate freely.

The sleeve 7 is generally cylindrical and forms an outer locating tube comprising an upper portion 29 and a lower portion 31. The upper portion 29 projects above the height of the bulb 9 to restrict access to the sides of the bulb 9 and the drive pin 21 The lower portion 31 extends over the sidewall 11 of the cover 5 to restrict access to the cover 5 In the present embodiment the lower portion 31 of the sleeve 7 projects beyond the base of the cover 5 to provide additional protection The bulb 9 may be referred to as an inner location bulb 9 in view of its position inside the sleeve 7 The bulb 9 has a smooth outer surface that advantageously may make it more difficult for an individual to grip the bulb 9 by hand and unscrew the cover 5 A specialist hydrant cap tool 33, as illustrated in figures 5, 6 and 7, is used to fit and remove the cap 1 according to the present invention The tool 33 according to the present embodiment comprises three distinct parts, namely an outer tube 35 provided with grips 37, an inner tube 39 and a top plate 41. All of these parts are preferably welded together to make one solid unit In use, the outer tube 35 fits over the sleeve 7 and the inner tube 39 locates over the bulb 9 The tool 33 can then be rotated clockwise or anticlockwise to install or remove the cap 1 from the outlet of the underground fire hydrant 3 The sleeve 7 serves to locate the tool 33 in position, although this is not essential.

In order to remove or install the cap 1 from the outlet of the fire hydrant 3 the cover must be rotated The cover 5 is protected by the sleeve 7 which rotates both clockwise and anticlockwise (see Figure 1) around the cover 5 via the first ball bearing 19 that is located between the cover 5 and the sleeve 7, In order to rotate the cover 5 the drive pin 21 needs to be rotated around a central position. The drive pin 21 has a screw thread at one end The drive pin 21 is passed through both the upper plate 17 and the cover 5 and is held in place at the cover end with weld and at the upper plate end by a nut 25 The drive pin 21 is protected by the bulb 9 The bulb 9 can be rotated clockwise and anticlockwise (see Figure 1) around the drive pin 21 via the second ball bearing 27 that is located between the drive pin 21 and the bulb 9 Figure 3 provides a graphical representation of the existing underground fire hydrants and Figure 4 shows the hydrant with the cap 1 fitted A nut and/or bolt shield 43 has also been fitted in this case at least partially to cover the nuts and/or bolts provided on the hydrant 3 The nut and/or bolt shield 43 is preferably a collar fitted over the outlet of the hydrant 3 and secured in place when the cap 1 is fitted A modified version of the first embodiment of the cap 1 is shown in Figure 2B The cap 1 has been modified to omit the locking pin 23 to simplify construction Moreover, the bulb 9 is an interference fit on the drive pin 21 and the nut 25 has been omitted An inwardly projecting ring 45 is formed on the inside of the sleeve 7 coincident with the first bearing 19. A flange 46 is provided at the top of the ring 45 for covering the outer edge of the top surface of the upper plate 17 The flange 46 covers the outer edge of the upper plate 17 and thereby provides additional protection against tampering A cap 101 in accordance with a second embodiment of the present invention is shown in Figures 8 and 9 The cap 101 is similar to the cap 1 of the first embodiment and like reference numerals have been used for like components but incremented by 100 for clarity The cap 101 is again intended to be located on a fire hydrant to help prevent tampering. The bulb 9 of the first embodiment has been replaced in the second embodiment with a conical drive member 109 for applying a driving force to the cap 101 The conical drive member 109 is mounted on a shaft 121 and is oriented such that its base is located proximal the upper plate 117, At least in preferred embodiments, the conical drive member 109 may protect the shaft 121 from tampering The shaft 121 has a longitudinal axis B' which is parallel to but offset from the first axis A' of the cap 101 A plan view of the cap 101 showing the conical drive member 109 in relation to the sleeve 107 is shown in Figure 9 The offset between the first and second axes A', B' in the second embodiment is 10mm The rotatable sleeve 107 has been modified to define an inwardly projecting ring coincident with the first bearing 119 and the upper plate 117 The ring 145 defines an annular surface 147 for supporting a shaft plate 149 This arrangement is desirable since the shaft plate 149 may offer additional protection for the first bearing 119 A space is maintained between the upper plate 117 and the shaft plate 149 As shown in Figures 8 and 10, the tool 133 for use with the cap 101 according to the second embodiment has a conical recess 134 for receiving the conical drive member 109. Although an outer surface of the tool 133 may be knurled, grips are not provided Rather, a keyed recess 151 is provided in the top of the tool 133 for receiving a drive handle 153 As illustrated in Figure 11, the handle 153 comprises a hand grip 155 and a keyed end 157 locatable in the recess 151 The operation of the cap 101 according to the second embodiment is generally unchanged from the cap 1 of the first embodiment However, it will be appreciated that the tool 133 locates on top of the cap 101 and does not extend around the sleeve 107 Furthermore, the handle 153 is required to rotate the tool 133 once it has been located on thecaplOl The cap 1, 101 according to the present invention may provide security for the outlet of the fire hydrant 3 It has two rotating elements 7, 9, 107, 109 and works on the principle that there is nothing static on the outside body to enable anybody to remove the cap by hand In addition, due to the design of the cap 1, 101, if a tool was manufactured to fit over either rotating part then it would either simply rotate on its own axis or would slip off Eitherway the cap 1, 101 would remain in place Thefirehydranttool 33; 133 fits securely over both rotating parts 7, 9; 107, 109 of the cap 1; 101 This enables the inner off centre locating pin 21; 121 to be rotated which in turn rotates the female cap screw 5; for the easy removal of the cap 1, 101 It will be appreciated that various changes and modifications may be made to the preferred embodiment without departing from the spirit and scope of the present invention Moreover, although the tamper resistant cap has been described with particular reference to a fire hydrant, the skilled person would understand that the cap could be used on a range of inlets or outlets Indeed, the cap may be adapted for sealing a container or vessel, such as a bottle or jar

Claims

Claims: 1 A tamper resistant cap comprising a cover for fitting over an

opening, the cover being adapted to be removed from the opening by rotation about a remova axis, drive means positioned on the cover offset from the removal axis, by which drive means the cover may be rotated about the removal axis to remove the cover from the opening, and a sleeve surrounding the drive means at least circumferentially with respect to the removal axis, the sleeve being freely rotatable with respect to the cover 2 The tamper resistant cap of claim 1, wherein the cover has a screw thread or bayonet fitting for engaging with the opening 3 The tamper resistant cap of claim 1 or claim 2, wherein the drive means is a member extending along a drive axis parallel to the removal axis 4 The tamper resistant cap of claim 3, wherein the member is rotatable about the drive axis.

The tamper resistant cap of claim 3 or claim 4, wherein the drive means is a cone centred on the drive axis and oriented with its tip away from the cover 6 The tamper resistant cap of any one of claims 3 to 5, wherein the drive means is mounted on the cover and a drive pin extends from the drive means to the cover 7. The tamper resistant cap of claim 6, wherein the drive means covers the drive pin 8 The tamper resistant cap of any one of the preceding claims, wherein the sleeve is mounted on a bearing provided between the cover and said sleeve 9 The tamper resistant cap of claim 8, wherein the bearing is enclosed by said sleeve 10. The tamper resistant cap of any one of the preceding claims, wherein the sleeve surrounds both the cover and the drive means 11 The tamper resistant cap of any one of the preceding claims, wherein the sleeve is freely rotatable in one direction and is prevented from rotating relative to the cover in the opposite direction 12 The tamper resistant cap of any one of the preceding claims, wherein the cap is a fire hydrant cap for covering the outlet of a fire hydrant 13 A tool for removing the tamper resistant cap of any one of the preceding claims 14 A tool for removing a tamper resistant cap, the tool comprising a locating member for locating the tool on the tamper resistant cap and engagement means for drivingly engaging a drive means provided on the cap A secure fire hydrant cap for securing the outlet of a fire hydrant, the cap comprising a first rotating part, a second rotating part and a female cap screw, the first rotating part being an outer locating tube for shielding the female cap screw, the outer locating tube being rotatable relative to the female cap screw, and the second rotating part being an inner locating bulb for securing an inner locating pin 16 A fire hydrant cap removal tool for removing a secure fire hydrant cap having first and second rotatable parts, the tool being adapted to fit over both the first and second parts of the secure fire hydrant cap