The invention is further described by means of example but not in any limitative sense with reference to the accompanying drawings of which:
FIG. 1 is a perspective view of a locking arrangement in accordance with the present invention;
FIGS. 2 to 4 illustrate components of the locking arrangement and tool;
FIG. 5 illustrates the socket of the arrangement;
FIGS. 6 and 7 illustrates the bolt and pinion;
FIG. 8 is a cross-sectional view of the locking arrangement;
FIG. 9 illustrates the tool;
FIG. 10 illustrates the tool inserted into the security plug;
FIG. 11 comprises a plan and side and end elevations of the bolt;
FIG. 12 shows the housing of the locking arrangement;
FIG. 13 shows the socket and pinion;
FIG. 14 shows the lower housing of the locking arrangement;
FIG. 15 shows the security plug;
FIG. 16 shows the head of the tool; and
FIG. 17 shows a cross-sectional view of the locking arrangement showing removal of the security plug.
FIG. 1 is a perspective view illustrating a locking arrangement of an access chamber cover in accordance with the present invention. The cover (1) composed of composite polymeric material has a non-slip upper surface (2) in conventional manner. The locking arrangement comprises an upper surface (3) defining a socket (4). A bolt (5) is supported by a bearing sleeve (7) in a guideway (11) extending from a housing (6). The housing (6) forms a rib for reception into a complimentary shaped recess in the supporting frame (not shown) for the access cover. The actuation tool has a head (not shown) supported by a tapering portion (9). The head is inserted into a socket in the locking mechanism housing (10) described in greater detail below.
In use of the locking arrangement the tool (8, 9) is inserted into the opening (4) in the locking mechanism (3). Rotation of the shaft (8) causes the bolt (5) to be driven outwardly from the sleeve (11) securing the cover within the surrounding frame (not shown). The tool is then removed and a dirt excluding security plug and deadlocking bar (not shown) are inserted into the opening (4) to close and seal it.
FIG. 2 is a schematic view illustrating the moving components. The bolt (5) is extended from the sleeve (11). The bolt (5) carries a toothed rack (12) which engages a pinion (13). The rack (12) is laterally offset from the centre line of the bolt (5), sleeve (11) and the access of the tool (8, 9) and locking device. Rotation of the shaft (8) causes the pinion (13) to rotate in parting linear movement to the bolt (5).
FIG. 3 is a further perspective view illustrating the arrangement shown in FIG. 2. In FIG. 3 the bolt (5) is extended, the tool (9) having been rotated through 90°. In FIG. 4 the bolt (5) is retracted the tool being rotated so that the cross member (14) is disposed transversely of the access of the bolt (5). In this position a lifting device (not shown) located on the ground beside the cover can be used to lift the tool (9) to release the cover if it is stuck within the frame, for example due to an accumulation of debris.
FIG. 5 illustrates the upper housing or bolt or the socket for reception of the tool. The upper cover (15) has an axial cylindrical bore and two diametrically opposed radially extending recesses (16) adapted to receive the protuberances of the head of the tool. The tool must be correctly aligned so that the head is inserted in the manner of a key into a lock. As shown in FIG. 5 the pinion (13) has been rotated through 90° so that the lower part (17) of the recess is aligned with a rebate (19) in a downwardly facing surface of the plate (15). When the tool (not shown) is raised protuberances engage the rebate (19) securely holding the access cover enabling it to be lifted safely.
FIG. 6 shows the bolt (5) and rack (12) engaging the pinion (13). The socket (18) and two diametrically opposed recesses (17) receive the head of the tool (not shown). Rotation of the head of the tool extends or retracts the bolt (5) locking or unlocking the cover from the surrounding frame.
FIG. 7 illustrates the bolt and pinion arrangement from below, The teeth extend half of the circumference of the pinion and engage the corresponding teeth (20) of the rack (12). A rebate (21) serves to receive a spring (not shown). The spring urges the pinion upwardly into contact with the upper portion of the housing (22) as shown in FIG. 8. This prevents seepage of dirt or contaminants downwardly into the rack and pinion arrangement.
FIG. 8 is a cross-sectional view of the locking arrangement. The security plug (23) has four wedge-shaped notations (24) on the upper surface adapted to receive a tool for insertion or removal of the security plug. The wedge-shaped portions are configured so that a tool driven vertically downwardly into the cap displaces any dirt or contaminants contained in the recesses (24). The construction of the security plug is shown in greater detail in FIG. 15. A sealing ring (25) serves to ensure a tight seal with the housing.
A socket (26) including a spring clip (27) located on the lower surface of the security plug is to receive a ball head (28), a locking member (29) as shown in FIG. 8. The locking member is generally rectangular in section and extends downwardly into the socket being received in the rebates (16) and (17) to provide a deadlocking arrangement. When inserted, the locking member (29) prevents rotation of the pinion so that the bolt (5) is locked in the extended position).
FIG. 9 illustrates the tool in accordance with the invention. The shaft (8) carries a cross-member (31) and handles (32). The handles may be detachable to allow convenient storage and transportation of the tool. A tapered shank (9) is secured to the shaft (8) by means of a pivot member (14). The pivot member may incorporate a hinge to allow rotation of the shank (9) merged to the shaft. Alternatively, the pivot member may be fixed so that the shank (9) is maintained at a constant orientation convenient to allow actuation of the tool. The head of the tool (33) is key-shaped having two diametrically opposed protuberances (34) to facilitate insertion into the socket when in the correct orientation.
FIG. 10 illustrates use of the tool for removal of the security plug. A plug engaging member (35) is inserted on the distal end of shaft (8) allowing the plug to be inserted or removed without need for a user to bend down.
FIG. 11 is a detailed view illustrating the bolt (5) and integral tooth rack (12). As shown in FIG. 11 the tooth rack (12) is laterally offset from the axis of the bolt. The rack (12) is also offset vertically from the axis of the bolt to accommodate the pinion shown in greater detail in FIG. 13.
FIG. 12 shows the construction of the upper housing portion. The upper housing portion forms a cover over the socket provided by the lower housing portion and pinion shown in FIGS. 13 and 14. The upper covering portion of the housing (15) has an axial bore and two diametrically opposed radially extending recesses (16) which form a socket for reception of the T-shaped head of the tool. Rotation of the tool in the socket allows the protuberances of the tool to be received in the two rebates (19), locking the tool into the housing to facilitate removal of the cover.
FIG. 13 illustrates the pinion, the socket (18) and diametrically opposed recesses (17) have a cup-shaped configuration to snugly receive the head of the tool. A sleeve extending downwardly from the cup-shaped portion includes a cylindrical toothed Gear (36) adapted to drive the rack (20) to actuate the bolt (5).
The lower housing portion is shown in FIG. 14. A sleeve (11) adapted to receive the bolt (5) and seal (7) has a guideway (37) to receive the rack (12). A cup (38) receives the pinion (13) allowing rotation of the pinion in use.
FIG. 15 shows the security plug.
FIG. 16 is a detailed view of the head of the tool, the shank (9) being fixed in relation to the shaft.
FIG. 17 is a cross-sectional view showing the attachment of the tool to the security plug (23) for insertion or removal of the plug. The tool has wedge-shaped teeth (35) adapted to be received into and engage the wedge-shaped recesses (24) on the upper face of the security plug. The angle of the wedge-shaped teeth (35) is more acute than the corresponding angle of the recess (24). In this way, insertion of the tool into the recesses ejects dirt and debris which may have accumulated, avoiding the need for separate cleaning of the security plug prior to removal.
Patent Application
20070252392
