阅读说明：本技术 用于共用设施库的屏蔽式自闩锁锁定组件 (Shielded self-latching locking assembly for shared utility stores ) 是由 爱德华·J·布尔克 于 2021-04-21 设计创作，主要内容包括：本发明涉及一种用于将盖牢固地封闭在封围件比如地坪平面公用设施库上的屏蔽式锁定系统,该锁定系统包括：L形螺栓,L形螺栓连接至位于盖的下侧部上的受弹簧偏置的滑动构件,L形螺栓在开槽壳体中旋转,开槽壳体将L形螺栓牢固地保持在盖下方,滑动构件在盖于封围件中的开口上方被盖上的向下的力向下迫压时接合封围件内侧的抵接部,该向下的力逐渐使闩锁部因与抵接部接触而抵抗弹簧偏置而缩回、然后使闩锁部卡扣到抵接部下方的弹簧偏置锁定位置中；以及非导电性的覆盖件,该覆盖件定位在锁定系统上并连接至锁定系统,以将L形螺栓屏蔽而免受封围件内的导电性影响。(The present invention relates to a shielding locking system for securely closing a cover on an enclosure, such as a floor level utility store, the locking system comprising: an L-bolt connected to a spring biased slide member on the lower side of the cover, the L-bolt rotating in a slotted housing that holds the L-bolt securely under the cover, the slide member engaging an abutment inside the enclosure when the cover is forced downwardly over the opening in the enclosure by a downward force on the cover that gradually retracts the latch against the spring bias as a result of contact with the abutment and then snaps the latch into a spring biased locked position under the abutment; and a non-conductive cover positioned over and connected to the locking system to shield the L-bolt from electrical conductivity within the enclosure.)

1. A shielded locking system for securely closing a lid on an enclosure, the locking system comprising: a spring biased slide member positioned within a non-conductive cover on a lower side of the lid; and an L-bolt, a leg portion of the L-bolt coupled to the sliding member; the elongated shaft portion of the L-bolt is rotatable in a slotted housing that securely retains the L-bolt beneath the cover; the latching portion of the sliding member being adapted to engage a rim or other abutment located inside the enclosure when the lid is urged downwardly over the opening in the enclosure, such downward force on the lid progressively causing the latching portion to retract against the spring bias as a result of contact with the rim or abutment and then snap the latching portion into a spring biased locked position located below the rim or abutment; the shaft portion of the L-bolt is accessible from outside the cover for rotating the L-bolt to retract the latch against the spring bias and from a locked position of the latch sufficiently to remove the cover from the enclosure, the non-conductive cover having a channel for receiving the spring-biased slide member and guiding the travel of the slide member, wherein the cover shields the locking system from electrical conductivity within the enclosure.

2. The locking system of claim 1, wherein the cover includes a rib wall for engaging an end of a spring in the sliding member.

3. The locking system of claim 1 wherein the cover has a flange portion for positioning over the leg portion of the L-bolt.

4. The locking system of claim 1, wherein the cover further provides shielding for fasteners used to attach the locking system to the cover.

5. The locking system of claim 1 wherein the cover has an open end for passing the latch portion to engage the rim or other abutment on the inside of the enclosure.

6. A shielded self-latching locking system for securely closing a lid on an enclosure, the locking system comprising:

a non-conductive cover secured to a lower side of the cap;

a sliding member disposed within the cover, a latching portion of the sliding member positioned to engage an abutment located inside the enclosure when the lid is forced downwardly over the opening in the enclosure;

a resilient spring member disposed in the slide member;

the spring member normally biases the latch to an extended position adapted to contact the abutment on the enclosure,

the sliding member is adapted to slide within the cover to a retracted position against the bias of the spring member as the latch contacts the abutment with a downward force when the cover is urged downward over the opening in the enclosure,

the slide member is adapted to move to the extended position with a snap action under the bias of the spring member when the downward force causes the latch to bypass the abutment on the enclosure and release contact with the abutment,

the latch in the extended position is held in a locked position below the abutment via the bias of the spring member; and

an L-bolt having a shaft portion positioned in the cover adjacent the sliding member and a leg portion coupled to the sliding member between the spring member and the latch,

the cover guides spring-biased axial travel of the slide member between the extended position and the retracted position in coordination with rotation of the shaft portion of the L-bolt,

the shaft portion of the L-bolt is accessible from outside the cover for rotating the L-bolt to retract the latch from the locked position against the spring bias sufficiently to remove the cover from the enclosure.

7. The locking system of claim 6, wherein the cover includes a rib wall for engaging an end of the spring member in the slide member.

8. The locking system of claim 7 wherein the cover has a flange portion for positioning over the leg portion of the L-bolt.

9. The locking system of claim 7, wherein the cover further provides shielding for fasteners used to attach a guide frame to the cover.

10. A locking system according to claim 6 wherein the cover has an open end for passing the latch portion to engage the rim or other abutment on the inside of the enclosure.

11. The locking system of claim 7, wherein the sliding member has a channel for receiving the spring member.

12. An apparatus enclosure assembly comprising a hollow enclosure, a cover for removably closing a top of the enclosure, and a shielding locking assembly for securely locking the cover to an opening in the enclosure, wherein the enclosure has a locking surface positioned adjacent a rim or abutment on an inner wall of the enclosure, the shielding locking assembly being positioned adjacent a rim of the cover so as to mate with the locking surface of an interior side of the enclosure, the shielding locking assembly comprising:

a self-latching slide member slidably disposed in a cover secured to a lower side of the lid;

a spring member of resilient bias engaging the slide member to control spring biased travel of the slide member toward and away from the locking surface;

a latch carried on the slide member and adapted to contact the rim or the abutment on the enclosure by a downward force applied to the lid positioned in the opening of the enclosure, the latch retracting the slide member against the spring bias as the latch travels over the rim or the abutment in response to the downward contact force applied to the rim or the abutment and then snap-locking the latch into spring-biased engagement with the locking surface below the rim or the abutment to lock the lid to the opening in the enclosure;

an L-bolt rotatably disposed in the cover, the L-bolt being rotatable between an unlocked position and a locked position;

a slotted structure attached to the lower side of the cover, the slotted structure projecting downwardly away from the lower side of the cover to a downwardly facing opening on the slotted structure spaced below the cover and positioned adjacent to the locking surface and adjacent to the guide frame, the L-bolt extending through a passage in the cover and a passage in the slotted structure to the lower side of the cover;

the L-shaped bolt has: (1) a right-angled leg projecting below the bottom of the slotted structure; and (2) a position adjustment device exposed to an upper surface of the cover;

a separate locking member inserted into the passage in the slotted structure and positioned around the L-bolt once the L-bolt is positioned in the passage through the slotted structure to prevent removal of the L-bolt from the exterior of the cover;

the right-angled leg of the L-bolt is coupled to the slide member such that sliding travel of the slide member causes rotation of the L-bolt;

the cover guides spring-biased axial travel of the slide member in coordination with rotation of the L-bolt in the slotted housing, the snap action of the latch engaging the locking surface in the enclosure causing rotation of the L-bolt to a spring-biased locking position, rotation of the L-bolt in a direction away from the locking position retracting the slide member against the spring bias to allow removal of the lid from the enclosure.

13. The enclosure assembly of claim 12, wherein said cover includes a rib wall for engaging an end of said spring member in said slide member.

14. The enclosure assembly of claim 13, wherein said cover has a flange portion for positioning over said leg portion of said L-bolt.

15. The enclosure assembly of claim 13, wherein said cover further provides shielding for a fastener used to attach said cover to said lid.

16. The enclosure assembly of claim 12, wherein said cover has an open end for passing said latch portion therethrough to engage said abutment on an inner side of said enclosure.

17. The enclosure assembly of claim 13, wherein said slide member has a channel for receiving said spring member.

18. The enclosure assembly of claim 12, wherein said enclosure is a utility depot.

19. The enclosure assembly of claim 18, wherein the utility repository houses underground communication equipment.

20. The enclosure assembly of claim 12, wherein the cover is non-conductive.

Technical Field

The present invention relates to a shielded locking system for closing and securely locking a cover to an enclosure such as a floor level box or utility store.

Background

The shielded locking assembly of the present invention provides security for enclosures such as floor level utilities stores, for example, for housing cable TV equipment, data transmission lines, telephone switching equipment, service lines, power transmission equipment, and water meters. The present invention is also generally applicable to other types of floor level enclosures and similar enclosures. One aspect of the present invention is to prevent conductive contact between any equipment that may be installed in a floor level box and the locking assembly of the self-latching when the cover for the enclosure is simply placed on top of the enclosure and forced down to the locked position by merely applying foot pressure to the top of the cover. Thus, the shielded locking system prevents a conductive path from within the enclosure to the exterior of the device to prevent electrical shock from occurring when the cover is installed or other accidental contact is made from outside the enclosure.

Disclosure of Invention

Briefly, one embodiment of the present invention includes a shielded self-latching locking assembly for locking a lid to the top of a hollow enclosure. The locking assembly includes a spring biased latch that engages a locking surface of the inside of the enclosure, and a cover that separates the locking assembly from various internal components within the enclosure and covers the enclosure. The locking surface may be a rim or wall section of the enclosure or may be a recess formed in an inner wall of the enclosure. The locking assembly may be positioned on the lid adjacent an edge of the lid. When the lid is seated on the enclosure and the latch is actuated by, for example, a downward force, such as foot pressure, against the top of the lid, the locking assembly cooperates with the locking surface inside the lid to lock the lid to the top of the enclosure.

One embodiment of the present invention includes a self-latching locking assembly positioned on an edge of a lid removably mounted on an enclosure. The assembly includes an opening in the upper face of the lid that leads to a slotted housing on the lower side of the lid. An L-bolt extends through the opening and into a passage in the slotted housing. The right angle leg on the L-bolt projects from below the bottom of the slotted housing. The L-bolt can be rotated by a tool engaging the L-bolt from outside the cover. A separate lock positioned within a passage in the slotted housing retains the L-bolt in the slotted housing and prevents the L-bolt from being removed by being accessed from outside the cover. The right-angled leg of the L-bolt engages a spring-biased, self-latching slide member on the underside of the lid. The slide member is received in a guide frame structure attached to the lower side of the cover adjacent a slotted housing that receives the L-bolt. The guide frame structure guides the spring-biased axial travel of the slide member, which travels axially in the guide frame in coordination with the rotation of the L-bolt in the slotted housing. A latch carried on the slide member engages a lip or other abutment on the inside of the enclosure as the lid is forced downwardly over the opening of the enclosure. The latch retracts against the spring bias as the latch travels over the lip or abutment and then snaps into engagement with a locking surface, such as a notch positioned on the inside of the enclosure below the lip. The latch retracts under the bias of a spring, which then causes the latch to snap into engagement with the locking surface as the latch travels over a lip or abutment inside the enclosure. This rotates the L-bolt to the spring biased locked position. Rotation of the L-bolt in a direction away from the locking position retracts the slide member against the spring bias. The L-bolt may be accessed from the exterior of the enclosure via a tool, such as a socket wrench or the like, to rotate the L-bolt away from the locked position, retracting the latch against the bias of the spring to allow removal of the lid. A cover is positioned over the locking assembly to cover all conductive components of the assembly, including the L-bolts, springs, and attachment fasteners, thereby separating any possible contact or current path from the enclosure.

In another embodiment of the present invention, the self-latching locking assembly includes a simplified spring-biased self-latching slide member on the underside of the lid. The location and position of the sliding member is controlled by a cover positioned on the lower side of the lid adjacent to a slotted housing that houses an L-bolt. The cover guides the axial travel of the slide member under spring bias, the slide member traveling axially within the cover in coordination with the rotation of the L-bolt in the slotted housing. A latch carried on the slide member engages a lip or other abutment inside the enclosure when the lid is forced down over the opening in the enclosure. The latch retracts against the spring bias as it travels over the lip or abutment and then snaps into engagement with a locking surface, such as a notch located inside the enclosure below the lip. The latch retracts under the bias of a spring, which then causes the latch to snap into engagement with the locking surface as the latch travels over a lip or abutment inside the enclosure. This rotates the L-bolt to the spring biased locked position. Rotation of the L-bolt in a direction away from the locking position retracts the slide member within the cover against the spring bias. A cover is positioned over the locking assembly to cover all conductive components of the assembly, including the L-bolts, springs, and attachment fasteners, thereby separating any possible contact or current path from the enclosure.

Thus, the lid may be positioned over the opening in the enclosure and then automatically locked in a safe closed position, for example simply by applying a downward force such as foot pressure, without using any tools for locking the lid and without fear of electric shock. These and other aspects of the invention will be more fully understood by reference to the following detailed description and the accompanying drawings.

Drawings

FIG. 1 is a front view illustrating a self-latching locking assembly according to principles related to the present invention. In this view, the shield-type cover has been removed and the latch on the locking assembly is shown in a locked position on the underside of the lid, thereby closing and locking an enclosure, such as a floor level box.

FIG. 2 is a perspective view of the locking assembly shown in FIG. 1, showing the latch in a retracted, unlocked position.

Fig. 3 is a perspective view illustrating a guide frame according to the principles of the present invention.

Fig. 4 is a perspective view illustrating a sliding member according to the principles of the present invention.

Fig. 5 is a partial perspective view illustrating an L-bolt actuator and a bolt recess of a cover housing a locking assembly in accordance with the principles of the present invention.

FIG. 6 is a partial perspective view similar to FIG. 4 showing an L-shaped bolt positioned in the bottom of the bolt recess.

Fig. 7 is a perspective view taken from the bottom side of the lid and showing the L-bolt positioned in the slotted housing.

Fig. 8 is a perspective view showing the locking member in the process of being inserted into the slotted housing portion of the locking assembly.

FIG. 9 is a partial bottom perspective view showing an alternative embodiment of an L-bolt actuator for the locking assembly of the present invention.

Fig. 10 is a partial perspective view, partially in cross-section, of the assembly shown in fig. 9.

Figure 11 is an exploded perspective view of the locking assembly and a cover for the locking assembly.

Fig. 12 is a perspective view of fig. 11 showing the cover when initially installed on the locking assembly.

Fig. 13 is a perspective view of fig. 12 showing the cover installed in a final position on the locking assembly.

Figure 14 is a perspective view showing a floor level box and a cover plate assembly housing the locking device of the present invention for locking the cover plate to the top of the floor level box.

Figure 15 is a partial side view showing a cover for a floor level box with a locking assembly in an unlocked position prior to the cover being moved to a locked position.

Fig. 16 is a side view, partially in cross-section, showing a cover for a floor level box, wherein the cover houses a self-latching locking assembly in an unlocked position.

FIG. 17 is a side view similar to FIG. 16 showing the self-latching locking assembly in the process of being locked and with the latch portion in the retracted position.

Fig. 18 is a side view similar to fig. 16 and 17 but showing the self-latching locking assembly in the locked position.

Figure 19 is a side view showing the latch portion of the locking assembly retracted to the unlocked position by rotation of the L-bolt.

FIG. 20 is an exploded perspective view of an alternative embodiment slide member and cover for the self-latching locking assembly.

Fig. 21 is a bottom view of the slide member and cover of fig. 20.

Fig. 22 is a perspective view of the embodiment of fig. 20 in installed detail.

Figure 23 is an installation detail perspective view of the latch of figure 22 illustrating the retracted position.

Detailed Description

Fig. 1 and 2 show a self-latching locking assembly 21, the self-latching locking assembly 21 being secured to the underside of a cover 22, the cover 22 closing and securely locking an enclosure such as a floor level box. The locking assembly is shown in a locked position in fig. 1 and in an unlocked position in fig. 2. Both cases are described in more detail below. For a clearer understanding of the locking assembly, covers for the locking assembly, which will be illustrated and discussed in more detail below, are not shown in these drawings.

The locking assembly is secured to the side portion of the lid such that the latching portion of the locking assembly can engage the locking surface on the inner wall of the enclosure. The cover may be made of molded thermoplastic or sheet molded composite or other material; and in one embodiment the cover is adapted to enclose and lock an enclosure such as a floor level utility store for housing, for example, cable TV equipment, data transmission lines, telephone switching equipment, and other similar service lines. The underside of the lid houses ribs 24, which ribs 24 project downwardly into the interior of the floor level box or other enclosure when the lid is in the closed position. These ribs may also extend at right angles to form a grid structure, and the locking assembly may be fastened to some of the downwardly facing ribs adjacent the edge of the cover.

The locking assembly includes an elongated guide frame 26, the guide frame 26 being secured to the underside of the cover by fasteners 28. The details of the guide frame are best shown in fig. 3. The guide frame has a flat base 30, a pair of upstanding, parallel left and right side walls 32 extending along opposite edges of the base, and a pair of inwardly projecting side rails 34 integrally formed with each side wall. The side rails have laterally spaced parallel inner edges 36, the inner edges 36 extending along opposite sides of a generally rectangular open space 38 facing outwardly from the guide frame structure. The base, side walls and side rails of the guide frame are formed as a molded integral piece of a rigid plastic material such as polypropylene.

An open space within the guide frame accommodates a slide member 40, the slide member 40 being adapted to be spring biased axially within the interior of the guide frame. The details of the slide member are best shown in fig. 4. The open space within the guide frame is shaped as a channel that is generally T-shaped in cross-section, and the slide member 40 has a conforming T-shaped cross-sectional configuration adapted to travel axially guided by the T-shaped base and sidewall structure of the guide frame 26.

The slide member 40 is divided into three parts:

(1) the front portion comprises a tapered latch 42, the tapered latch 42 axially travelling towards or away from a locking position in response to axial extension or retraction of the slide member within the guide frame. The latch is carried on or integrally formed with the front portion of the slide member 40.

(2) The rear portion includes an upwardly open generally U-shaped channel 45, the channel 45 accommodating the spring member 44. The channel is formed by narrow parallel side walls 46, the side walls 46 sliding against the side rails 34 on opposite sides of the guide frame. The cross-section of the slide member is generally T-shaped and the slide member is configured such that the flat base 47 of the slide member slides on the flat base 30 within the guide frame. When the sliding member is retracted its full length in the channel portion of the guide frame, the rear surface 48 of the sliding member engages the rear wall 50 of the guide frame which acts as a stop. Side flanges 51 on the base portion of the slide member slidably engage recessed areas under the inwardly projecting side rails 34 of the guide frame.

(3) The intermediate portion includes a connection for an L-bolt 52, the L-bolt 52 rotating in coordination with the axial travel of the slide member 40. In the illustrated embodiment, the L-bolt connection of the slide member includes an opening 54 formed in the slide member facing laterally outward, the opening 54 for contacting a right-angled leg 56 of the L-bolt. (the L-bolt will be described in more detail below). The opening 54 is positioned adjacent a ramp 58, the ramp 58 being formed on the middle portion of the slide member between the spring receiving channel 45 on the rear portion and the latch 42 on the front portion of the slide member. The right-angled leg 56 of the L-bolt loosely fits within the opening 54. In use, rotation of the L-bolt may rotate the right-angled leg against the ramp 58 to urge the slide member toward the retracted position against the bias of the spring member 44. When the spring tension is released, the slide member slides forward to the locked position. The right-angled leg of the L-bolt rotates in coordination with the forward movement of the slide member. The projection 59 on the guide frame is contacted by the leg portion of the L-bolt to prevent the slide member from traveling forward.

The spring member 44 is positioned in a channel 45 in the slide member 40. In the illustrated embodiment, the spring member comprises a coil spring, but other means of applying an axial spring force to the end of the slide member may be used. The coil spring is positioned on an elongated metal or plastic rod 60, which rod 60 extends axially through the center of the channel. The front portion of the rod is attached to the middle portion of the slide member at the front of the channel. The rear part of the rod passes through an opening in the rear wall 50 of the guide frame. A rod extends along the center of the coil spring to axially align the coil spring within the channel. As shown in fig. 2, retraction of the slide member within the guide frame causes the alignment rod to extend from the rear wall of the guide frame. In its normal state, the spring is in tension between the front of the channel and the rear wall of the guide frame 26.

Fig. 1 and 2 show the L-bolt 52 received in a slotted housing 61 attached to the lower side of the cover 22. The L-bolt and its slotted housing may be similar to the L-bolt locking assembly shown in applicant's U.S. patent No.7,547,051, the entire disclosure of which is incorporated herein by reference.

Referring to fig. 5 to 8, the top of the cover 22 has a cup-shaped bolt recess 62, and the bolt recess 62 is open to the top of the cover and protrudes downward toward the lower side of the cover. The bottom of the bolt recess includes a long narrow slotted housing 61, the slotted housing 61 communicating with an opening through the cover. The bottom portion of the bolt recess communicates with an opening through the slotted housing. As shown in fig. 5, the L-shaped bolt is inserted into an opening in the bolt recess at an angle. The lock nut 64 and the lower flange 66 are integrally formed with the top of the bolt. The L-bolt shaft is bent to form a right angle leg. The right angle leg of the L-bolt is pushed down into the bottom of the bolt recess as shown in fig. 5, then straightened and pushed to the bottom of the recess as shown in fig. 6. The right angle leg of the L-bolt extends parallel to and is spaced below the bottom of the slotted housing. The L-bolt may be rotated to rotate the right angle leg through a range of angular motion, as will be described in detail below.

Fig. 8 shows an embodiment in which a molded plastic lock 68 may be inserted into the bottom opening in the slotted housing. The locking member 68 is then driven upward into the slotted housing where the locking member 68 extends adjacent to the L-bolt shaft. The locking member is slidably fitted into an opening through the slotted housing. The bottom of the locking member has a flange portion that fits around the bottom edge of the housing when the locking member is in place in the opening through the housing.

Fig. 9 and 10 show an alternative form of L-bolt assembly. In this embodiment, the upright shaft 52 of the L-shaped bolt extends downwardly through the cylindrical housing 70, the cylindrical housing 70 extending below a cup-shaped recess 72 exposed to the upper surface of the cover. The cylindrical housing and the recess are integrally molded with the ceiling surface of the cover. A lock nut 64 at the top of the shaft is disposed in the recess 72 for accessing the top side of the cover. The right angle leg 56 at the bottom of the L-shaped bolt extends laterally away from the bottom of the cylindrical housing 70. An elongated slotted housing 74 molded integrally with the cylindrical housing receives a lock 76 provided in the housing for retaining the L-bolt in the housing 70.

Fig. 11-13 illustrate a cover 77 for placement on the locking assembly 21. Overlay 77 has the following profile: this contour covers the attachment fasteners 28, spring members 44, and actuating L-bolts 52 and separates the attachment fasteners 28, spring members 44, and actuating L-bolts 52 from the interior of the utility vault 80 and any equipment housed in the utility vault 80, thereby separating any possible contact or current path from the exterior from the vault interior. In the utility market, it is important and required that there is no metallic or electrically conductive contact between the equipment that can be mounted in the enclosure and the outside of the unit. The cover 77 provides shielding from contact with any conductive parts of the locking assembly and further provides shielding from accidental contact with the mechanism during use and during installation or removal of the cover plate or lid from the library.

The cover 77 includes a top portion 78 and a bottom portion 79, the top portion 78 being shaped to fit over the enclosed slide 40 and the bottom portion 79 being shaped to fit over the guide frame 26. The bottom portion 79 includes a fastener portion 81 shaped to fit over the fastener 28. An end wall 83 is positioned at one end of the cover, and the end wall 83 includes a hole 85 for receiving the end of the L-bolt 52 when positioned over the locking assembly. The cover also includes a flange portion to allow the right-angled leg 56 of the L-bolt 52 to operate. The end 87 of the cover 77 is open so that the latch 42 can be operated during installation and removal of the lid.

The handle 89 is positioned on the side rail 34 on both sides of the guide member 26 and the handle 89 extends upwardly through the recesses 91 on both sides of the bottom portion 79 of the cover. The recess 91 has a wider portion 93 and a narrower portion 95 adjacent to each other. As shown in fig. 12, to attach the cover 77 to the latch assembly, the cover 77 is positioned over the latch assembly and lowered onto the latch assembly such that the handle 89 extends through the wider portion 93 of the recess 91 with the top curved lip portion 97 of the handle projecting over and above the wider portion. As shown in fig. 13, cover 77 is then moved toward latch 42 such that the handle moves to narrower portion 95 of recess 91 and top lip portion 97 of the handle engages the top surface of bottom portion 79 to securely attach the cover to the locking assembly.

Fig. 14 shows an example of a floor level box or utility garage 80 having an upper opening that receives a cover panel or lid that encloses and securely locks the top of the garage. The cap may include a solid cover plate, such as cover plate 22, for enclosing the entire opening; or the cap may be a split cover plate having two portions 82 and 84, as illustrated in fig. 14. In this case, the cover includes a plug opening 86 and a removable plug 88 for receiving a base housing (not shown). The embodiment in fig. 14 shows a recess 90 located near the edge of the cover plate portion 82, the recess 90 accommodating an L-bolt connected to a locking device located on the underside of the lid. When the cover panel is positioned in the opening of the floor level box, the cover can be locked in place by the process of steps shown in fig. 15-19.

Figures 15 to 19 show the locking assembly in use. In these figures, cover 77 is not shown for better understanding of the operation of the locking assembly, it being understood that the cover would be positioned on the locking assembly as shown in fig. 13. Fig. 15 shows the lid 22 in its unlocked position positioned over the opening in the enclosure with the latch assembly spaced above the locking surface 92 inside the wall 94 of the enclosure. The side of the lid opposite the locking assembly may include a fixed stop 96, the fixed stop 96 engaging a notch 98 or other recess located below a rim 100 extending around the interior of the enclosure. A downwardly projecting lip 102 on the underside of the lid normally rests on the top surface of the inner rim 100 when the lid is closed. The lid also includes a flanged outer periphery 104, the flanged outer periphery 104 resting atop an upper edge 106 of the enclosure when the lid is finally moved toward the closed position.

Figure 16 shows the movement of the lid towards its locked position under a downward force applied to the top of the lid. Here, the latching portion of the locking assembly engages the outer edge of the rim 100 as the lid is moved downwardly toward the locked position. In this case, initial contact occurs between the edge and the bottom portion of the taper 108, wherein the taper 108 extends at an angle along the outer edge of the latch 42. The latch is spring biased outwardly to the latch unlocked position by spring tension applied to the end of the slide member 40.

Figure 17 shows an intermediate step in the process of moving towards the locked position under the downward force applied to the lid. Here, the leading end of the latch 42 engages the inner edge of the rim 100 causing the latch to retract inwardly against the spring bias, guided in its axial travel by the side rails of the guide frame 26. In the position shown in fig. 17, the latch portion applies a spring-biased tension to the inner surface of the rim. In addition, retraction of the slide member into the guide frame causes the L-bolt shaft 52 to rotate in coordination with the axial travel of the slide member against the spring bias. The L-bolt shaft rotates through an angle in response to the rotation of the right-angled leg 56 of the L-bolt via its connection with the slide member 40. During retraction of the slide member, the end face of the slide member engages the rear wall of the guide frame 26, which acts as a stop against further axial travel against the spring bias.

FIG. 18 shows the latch assembly having been moved to its latched position. Here, once the lid reaches its closed position against the top 106 of the enclosure as shown in fig. 18, a downward force applied to the top of the lid causes the tapered edge 108 of latch 42 to move out of contact with edge 100. This causes the spring 44 to urge the slide member 40 to move the slide member 40 forward by a snap action, wherein the latch is automatically urged into engagement with the notch 92 located below the rim. During forward movement of the slide member and latch, the L-bolt rotates in unison with the slide member due to the connection between the right angle leg 56 of the L-bolt and the slide member.

In the latched position shown in fig. 18, the lid is securely locked in the closed position on the enclosure with the spring biased latch preventing removal of the lid. In the locked position, the top of the L-bolt is the only way to access the enclosure. Here, the L-bolt has been rotated to a locked position, and a lock disposed in the slotted housing adjacent the L-bolt shaft prevents removal of the L-bolt from the exterior of the enclosure.

Fig. 19 illustrates access to the enclosure. Here, a socket wrench 110 or other tool may be used to engage the nut atop the L-bolt for rotating the L-bolt away from its locked position. As shown in fig. 19, the connection of the L-bolt to the slide member causes the slide member to retract into the guide frame against the spring bias and move the latch portion away from its locked position. This provides an unlatching means to remove the lid from the enclosure.

Thus, when the lid is forced downwards on the open enclosure, such as by foot pressure, the sliding member is engaged in its locked position. The downward force on the cover gradually retracts the latch against the spring bias from contact with the abutment and then snaps the latch into the spring biased locked position. The L-bolt can be accessed from outside the lid, rotated by a socket wrench or similar special tool, to retract the latch sufficiently from its locked position to remove the lid from the enclosure.

Fig. 20-23 illustrate an alternative embodiment of a self-latching locking assembly 200, the self-latching locking assembly 200 secured to the underside of a lid 22 that closes and securely locks an enclosure, such as a floor level box. The locking assembly is shown in a locked position in fig. 22 and in an unlocked position in fig. 23.

The locking assembly includes an elongated cover 202 attached to the underside of the lid by fasteners 28. The cover has a base 204, a pair of upstanding, parallel side walls 206, 208 extending along opposite edges of the base, and an end wall 210. The end of the cover opposite the end wall 210 is open. The side walls 206, 208 and end wall 210 define a channel 212 or open space with the base 204 for receiving a slide member 214. A rib wall 216 extends from the end wall 210 into the channel. The cover and the slide member are formed by a moulding made of a hard plastics material such as polypropylene, but may also be made of other materials.

A channel or open space in the cover accommodates a slide member 214 for spring-biased axial travel within the cover. The channel or open space within the cover is generally rectangular in shape, and the slide member 214 has a consistent rectangular shape adapted for axial travel, guided by the base and sidewall structure of the cover.

As best shown in fig. 20, the sliding member 214 is divided into three sections:

(1) the front portion includes a tapered latch 218, the tapered latch 218 traveling axially toward or away from a locking position in response to axial extension or retraction of the sliding member within the channel of the cover. The latch is carried on or integrally formed with the front portion of the slide member.

(2) The rear portion includes an upwardly opening generally U-shaped channel 220, the channel 220 receiving a spring member 222. The channel is formed by narrow parallel side walls 224, 226, the side walls 224, 226 sliding against the side walls 206, 208 on opposite sides of the cover. The slide member is generally rectangular in cross-section and is configured such that the flat base 228 of the slide member slides over the flat base 204 within the channel of the cover. When the slide member is retracted its full length in the channel portion of the cover, the rear surface 230 of the slide member engages the inner surface of the end wall 210 of the cover, which acts as a stop. The spring member 222 comprises a coil spring, but other means of applying an axial spring force to the end of the slide member may be used. One end of the spring abuts a locator 231 positioned within the channel 220 adjacent the middle portion, and the rib wall 216 is located on the opposite end of the spring.

(3) The intermediate portion includes a connection for an L-bolt 52 shown in fig. 22, the L-bolt 52 rotating in coordination with the axial travel of the slide member 214. In the illustrated embodiment, the L-bolt connection of the slide member includes an opening 232 formed in the slide member facing laterally outward, the opening 232 for contacting the right-angled leg 56 of the L-bolt. The opening 232 is positioned adjacent a ramp 234 formed on the middle portion of the slide member between the spring receiving channel 220 on the rear portion and the latch 218 on the front portion of the slide member. The right angle leg 56 of the L-bolt loosely fits within the opening 232. In use, rotation of the L-bolt may rotate the right-angled leg against the ramp 234 to urge the slide member toward the retracted position against the bias of the spring member 222. When the spring tension is released, the slide member slides forward to the locked position. The right-angled leg of the L-bolt rotates in coordination with the forward movement of the slide member.

The cover 202 has the following profile: this contour covers attachment fastener 204, spring member 222, and actuating L-bolt 52 and separates attachment fastener 204, spring member 222, and actuating L-bolt 52 from the interior of utility vault 80 and any equipment housed in utility vault 80, thereby separating any possible contact or current path from the exterior from the interior of the vault. The cover 202 provides shielding from contact with any conductive parts of the locking assembly and further provides shielding from accidental contact with the mechanism during use and during installation or removal of the cover plate or lid from the library.

The base 204 of the cover 202 is shaped to fit over the enclosed slide member 214. The cover includes a fastener portion for receiving the fastener 204. The cover also includes a flange portion 236 to allow the right-angled leg 56 of the L-bolt 52 to operate. The flange portion 236 has an opening 240 so that, as shown in fig. 22, the assembly 200 can slide over the leg 56 of the bolt 52 during attachment of the assembly 200 to the lower side of the cover. The end 238 of the cover 202 is open so that the latch 218 can be operated during installation and removal of the cap. The operation of the assembly 200 is similar to that described for the embodiment shown in fig. 1-4.

While the invention has been described and illustrated with respect to the embodiments thereof, it will be understood that variations and modifications may be made which are within the full intended scope of the invention as hereinafter claimed.