Adjustable closure lock

A door closure for an electric meter box comprises a barrel lock, a lock receiver, a tie rod, a locking nut, and a base plate. The lock includes a shank portion, a head portion, and a flange. The head portion resides in a hole in the meter box door, and the flange captures the outside surface of the door. The lock shank is received by a hole in one end of the lock receiver. The hole has an internal groove for receiving the locking balls in the lock shank. The other end of the lock receiver receives the threaded end of a tie rod. The other end of the tie rod is welded to a base plate, which is screwed into the back of the meter box. The position of the lock receiver can be adjusted to match the depth of the meter box by screwing the receiver up or down on the tie rod. The position of the receiver is then fixed by a lock nut immediately behind the lock receiver. The lock receiver can also be aligned with the door hole by flexing the tie rod.

BACKGROUND 
1. Field of the Invention 
This invention relates to electricity meter boxes, in particular to an 
adjustable closure for securing the door of the meter box. 
2. Problems Addressed by the Invention 
In the utility industry, electricity meters are often enclosed in metal 
meter boxes with hinged metal or Plexiglas doors which allow access to the 
meter. A great number of these doors are secured only by a latch operated 
by a simple, low security key. As the incidence of energy theft via meter 
tampering has increased in recent years, many utility companies have found 
it necessary to retrofit their meter boxes with high security locks in 
order to prevent unauthorized access to the meters. The problem with 
retrofitting a large number of meter boxes is that the boxes tend to vary 
in shape and size. This requires the locking assembly used to secure the 
box doors to be customized for each box, making installation potentially 
expensive and time consuming. Also, the presence of the meter and cables 
in the box limit the space and surfaces available for mounting the locking 
assembly. 
3. Discussion of Prior Art 
In order to provide background information so that the current invention 
may be understood and appreciated in its proper context, reference is made 
to a meter box locking assembly in current use. In this assembly, an 
L-shaped bracket is mounted in the meter box on the bottom or side wall, 
and a hole in the bracket is aligned with a hole in the door of the box. A 
bushing having a lower threaded portion, a central flange portion, and an 
upper thin-walled portion, is inserted threaded end first into the door 
hole. The flange portion, having a larger diameter than the door hole, 
abuts the outside surface of the door, and the bushing is secured to the 
door with a locking nut. The bushing has a central hole with a larger 
diameter counter bore starting at the thin walled end, and extending 
almost to the bottom of the threaded portion. The thin-walled section 
contains several apertures for receiving a security seal like the one 
shown in U.S. Pat. No. 4,353,583 (1982, Moberg). 
When the door is locked, a barrel lock is used, such as the one shown in 
U.S. Pat. No. 4,742,703 (1988, DeWalch et al.). A barrel lock, as defined 
in the present disclosure, is commonly characterized as having a generally 
cylindrical case with a head portion, a smaller diameter shank portion, 
and a shoulder portion interposed between the head and shank portions. The 
shank portion includes locking means, usually a pair of retractable steel 
balls. The smaller diameter shank of the lock passes through the hole in 
the bushing until the shoulder portion of the lock abuts the bottom of the 
counter bore. In this position, the locking balls on the shank extend just 
beyond the hole in the L-shaped bracket. When the lock is locked, the 
locking balls protrude from the shank, and extraction of the lock is 
prevented by contact between the balls and the L-shaped bracket. Opening 
of the meter box door is prevented by contact between the bottom of the 
bushing counter bore and the lock head. 
The position of the L-bracket relative to the door hole is critical to the 
function of the locking assembly. Such precise positioning is difficult to 
achieve in field installations. Furthermore, the bracket is not adjustable 
once attached. Field installation of the prior art locking system is 
further complicated by the bottom or side wall position of the bracket, 
which makes it difficult to drill the anchor holes necessary to mount the 
bracket. Problems can also arise when using this assembly with barrel 
locks which are unlocked by rotation of the key. These locks, called 
rotationally actuated barrel locks, sometimes tend to rotate with the key, 
making it necessary to hold the lock case when unlocking the lock. The 
bushing in the prior art locking assembly completely covers the barrel 
lock case, thus preventing the user from holding the case. Whatever the 
precise merits, features and advantages of the above cited reference, none 
of them achieves or fulfills the objects of the present invention as set 
forth below. 
SUMMARY OF THE INVENTION 
Objects of the Invention 
Accordingly, several objects and advantages of my invention are: 
(a) To provide an adjustable door closure for an electric meter box. 
(b) To provide a door closure for an electric meter box which can be easily 
used with rotationally actuated barrel locks. 
(c) To provide an adjustable door closure for an electric meter box which 
is inexpensive to manufacture. 
(d) To provide an adjustable door closure for an electric meter box which 
is easy to install. 
(e) To provide a flanged barrel lock for use with meter box door closures. 
Brief Physical Description 
The preferred embodiment of the present invention is a door closure for a 
meter box, and includes a barrel lock with an external case. The case has 
an upper head portion and a smaller diameter lower shank portion which 
houses two retractable locking balls. The lock case also includes a flange 
and a ferrule portion with apertures for receiving a security seal. The 
lock head resides in a hole in the door of the meter box, and the flange 
abuts the outside surface of the door. The lock shank is received by a 
hole in one end of a cylindrical member called the lock receiver. This 
hole also has an internal groove on its circumference for receiving the 
locking balls when they are extended. The other end of the lock receiver 
contains a tapped hole, which receives the threaded end of a bolt like 
member called the tie rod. The other end of the tie rod is welded to a 
base plate, which is screwed into the back of the meter box during 
installation. Once the base plate and tie rod are in place, the position 
of the lock receiver can be adjusted to match the depth of the meter box 
by screwing the receiver up or down on the tie rod. The position of the 
receiver is then fixed by a lock nut immediately behind the lock receiver. 
The lock receiver can also be aligned with the door hole by flexing the 
tie rod. 
Present Invention vs. Prior Art 
The door closure of the present invention is easier to install than that of 
the prior art because it is attached to the back of the meter box, which 
is more accessible for drilling anchor holes than the bottom or side 
walls. The L-shaped bracket of the prior art is mounted on the bottom or 
side wall. Also, the adjustable nature of the present invention makes 
absolute positioning of the assembly during installation non-critical. The 
L-shaped bracket of the prior art must be precisely positioned for the 
assembly to lock properly and to minimize freeplay in the assembly when 
locked. Also, the present invention does not require the installation of a 
separate bushing in the door of the meter box. 
The present invention is easier to use with rotationally actuated barrel 
locks than the prior art. The flange and ferrule portions of the bushing 
in the prior art prevent access to the lock case. The flange and the 
ferrule of the present invention are non-separable parts of the case, and 
are readily accessible for holding by the user. Including the flange and 
the ferrule as non-separable parts of the lock case in the present 
invention eliminates the bushing and the lock nut from the assembly. This 
reduces the part count and makes the present invention less expensive to 
manufacture and easier to install. 
How the Present Invention Fulfills the Objects 
In the present invention, the threaded connection between the tie rod and 
the lock receiver allows the assembly to be adjusted for variations in 
meter box depth. The flexibility of the tie rod in the present invention 
allows the final alignment of the lock receiver with the door hole to be 
adjusted after the base plate is in place. This makes installation quick 
and easy, since the location of the base plate is less critical. Inclusion 
of the flange and the ferrule as part of the lock case allows the user to 
hold the lock case during actuation of the lock. This makes it easier to 
use a rotationally actuated barrel lock with this assembly. The present 
invention incorporates a small number of simply designed components, 
making the overall invention light weight and inexpensive to manufacture. 
A critical feature in simplifying the overall design is the inclusion of 
the flange and the ferrule as non-separable parts of the lock case. This 
eliminates both the bushing and the locking nut from the assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, the preferred embodiment of the present invention 
includes the barrel lock 10, lock receiver 30, tie rod 50, locking nut 60, 
base plate 70, and screws 80a through 80d. These components are used to 
secure the meter box 90, which has a back wall 92, top wall 93, side walls 
94a and 94b, and a door 96 with an aperture or hole 98. The door is hinged 
at 100. The term meter box in the present disclosure is used to refer to 
any base structure relative to which the position of the door is to be 
controlled. The external case 12 of the barrel lock 10 includes a ferrule 
portion 14 with apertures 16a and 16b for receiving a security seal, and a 
flange 18 immediately below the ferrule portion. Referring to FIG. 3, 
adjacent to the flange 18 is a head portion 20 which houses a locking 
mechanism similar to the one described in U.S. Pat. No. 4,742,703. Below 
the head portion is a smaller diameter shank portion 22 which houses a 
locking means comprising two retractable locking balls 24a and 24b, which 
protrude from the shank when the lock is locked. 
When the lock 10 is used to secure the meter box door 96, the head portion 
20 of the lock resides in hole 98 of the door. The flange 18 acts as an 
obstructing means, being shaped so as to prevent passage of the lock 10 
through the door hole. The lock receiving member or lock receiver 30 is 
generally cylindrical, and has a hole 32 in one end which receives the 
lock shank 22. This hole also has an internal groove 34 on its 
circumference which acts as a means for engaging the locking balls 24a and 
24b. The lock receiver is connected to the meter box by an adjustable 
attachment means, which comprises a tapped hole 36, which receives the 
threaded end 52 of a flexible member or tie rod 50. Referring to FIG. 1, 
the far end 54 of the tie rod is welded to the center of the base plate 
70. The base plate is a generally square, flat member which is attached to 
the back wall 92 of the meter box during installation via screw holes 72a 
through 72d and screws 80a through 80d. 
Referring to FIG. 2, once the base plate 70 is attached to the meter box 
90, the position of the lock receiver 30 can be adjusted to match the 
depth 102 of the meter box by screwing the receiver up or down on the tie 
rod 50. The position of the lock receiver is then fixed by lock nut 60 
immediately behind the lock receiver. The lock receiver 30 can be aligned 
with the door hole 98 in the door 96 by flexing the tie rod 50. Referring 
to FIG. 3, when the door 96 is closed, the lock receiver 30 acts as a stop 
for the door, providing proper alignment of the door with the meter box. 
The lock 10 is then inserted through the door hole and into the front hole 
32 in the lock receiver 30. The ferrule portion 14 of the lock is held by 
the user, if necessary, and the lock is locked. The locking balls 24a and 
24b now protrude into the internal groove 34 of the lock receiver. 
Referring to FIG. 2, if someone attempts to open the meter box door, the 
door will exert a force on the flange 18 on the lock 10. This force will 
be transmitted from the lock to the lock receiver 30, and then through the 
tie rod 50, base plate 70, and screws 80a through 80d to the back wall 92 
of the meter box. 
Alternative Embodiments 
In alternative embodiments, the barrel lock of the present invention can be 
used to secure any type of enclosure having a door. FIGS. 7 and 8 show an 
alternative embodiment door closure in which the preferred embodiment lock 
case 12 engages the L-shaped bracket 40 of the prior art. The bracket is 
mounted in a particular type of meter box 170 called a ringless meter 
socket. In this type of enclosure, the door 172 of the meter box retains 
the meter 180 in its socket in a manner well known in the industry. 
Referring to FIG. 8, the lock case 12 passes through the bracket 40. A 
bushing 41 is attached to the bracket 40 and engages the locking balls 24a 
and 24b to retain the lock. The bracket is attached to the wall 174 of the 
meter box 170 by a screw 42. 
In alternative embodiments, the barrel lock could be fixed to the door by a 
coupling means. In one such embodiment, as shown in FIG. 4, this coupling 
means comprises threads on the head portion 112 of the lock case 110, and 
a lock nut 120, which is used to secure the lock case to the meter box 
door 116. FIG. 9 shows the threaded lock case 112 engaging the L-shaped 
bracket 40 of the prior art, with nut 120 securing the lock case to the 
door 172. A bushing 41 is attached to the bracket 40 and engages the 
locking balls to retain the lock. The bracket is attached to the wall 174 
of the ringless meter socket by a screw 42. 
In other embodiments the door hole could be tapped and the threaded lock 
case screwed into the door. Also, the lock case could be attached to the 
door by more permanent means, such as welding, or the lock case could be 
formed from part of the door. In another alternative embodiment, as shown 
in FIG. 5, the base plate 130 has an L-shaped cross section, and is 
attached to the top wall 134 of the meter box. In other embodiments, the 
base plate could also be attached to one of the side walls of the meter 
box. 
In alternative embodiments, the adjustable attachment means between the 
lock receiver and the meter box could comprise a threaded connection 
interposed anywhere between these two members. FIG. 6 shows one such 
embodiment in which an internally threaded bushing 140 is attached to the 
base plate 144 by welding or other suitable means. The tie rod 150 is 
threaded on the far end 152, which is received by the bushing 140. The tie 
rod has a knob portion 154 at the end opposite the threaded end. The lock 
receiver 160 has a hole 162 at the end closest to the base plate 144. The 
diameter of this hole is smaller than the diameter of the head portion 154 
of the tie rod 150. When installed, the knob portion of the tie rod 
resides in the lock receiver 160, and is captured by the hole 162. 
Adjustments for meter box depth are made by screwing the tie rod 150 in or 
out of the bushing 140. In other embodiments, the tie rod and the lock 
receiver could be machined as a single piece. 
Conclusions, Ramifications, and Scope of the Invention 
The present invention is well adapted to carry out the objects and attain 
the ends and advantages mentioned, as well as others inherent therein. The 
threaded connection between the tie rod and the lock receiver allows the 
position of the lock receiver to be adjusted for variations in meter box 
depth. The flexibility of the tie rod in the present invention allows the 
final alignment of the lock receiver with the door hole to be adjusted 
after the base plate is in place. This makes installation quick and easy, 
since the location of the base plate is less critical. Inclusion of the 
flange and the ferrule as part of the lock case allows the user to hold 
the lock case during actuation of the lock. This makes it easier to use a 
rotationally actuated barrel lock with this assembly. The present 
invention incorporates a small number of simply designed components, 
making the overall invention light weight and inexpensive to manufacture. 
A critical feature in simplifying the overall design is the inclusion of 
the flange and the ferrule as part of the lock case. This eliminates both 
the bushing and the locking nut from the assembly, as compared to the 
prior art. While, for the purposes of disclosure there have been shown and 
described what are considered at present to be the preferred embodiments 
of the present invention, it will be appreciated by those skilled in the 
art that other uses may be resorted to and changes may be made to the 
details of construction, combination of shapes, size or arrangement of the 
parts, or other characteristics without departing from the spirit and 
scope of the invention. It is therefore desired that the invention not be 
limited to these embodiments and it is intended that the appended claims 
cover all such modifications as fall within the true spirit and scope of 
the invention.