DE2430642A1 - SECURITY SEAL DEVICE, IN PARTICULAR FOR USE IN ELECTRIC SUPPLY METERS - Google Patents

Description

SW 279/74 24 _O June 1974

Notifier:

S- \ NGMIO WESTON LIMITED, Great Cambridge Roac0Enfield,

"Security sealing device, especially for use in electrical utility meters "

The invention relates to a security sealing device for two parts to be held together, in particular for use in electrical supply meters with a housing cover and a housing base to be held together, which consists of a rigid, there is elongated bolt with threaded part, which reaches through a hole in each of the parts to be held together and over a zone with enlarged cross-section engages at one point along its length in a recess in one of the parts to be held together Parts is arranged.

Such safety victory devices are used to protect Measuring devices, in particular electrical supply meters, to open these devices for the purpose of falsifying the meter mechanism or fraudulently withdrawing electricity

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(or any other benefit) to become evident.

The majority of instruments, measuring devices, or apparatus that have a recording, measuring, or display mechanism within a Chamber that normally cannot "be accessed" have a chamber consisting of at least two parts Housing, namely a housing cover and a housing base, which must be held together in a secure connection. In the case of an electrical supply meter, the housing consists, for example, of a base that is attached to a meter board is, from a housing cover, which is attached to the base, and an electrical connection door through which the electrical Lead leads into the interior of the counter mechanism.

The traditional way of putting electrical utility meters against one Protecting unauthorized tampering with the meter mechanism consists of the use of wire and lead seals on the screws the meter cover and on the electrical connection door. Such seals consist of a wire that goes through a cross hole in the head of each fastening screw and through part of the meter housing, so that any attempt at a Turning the screws causes the sealing wire to break. As soon as the seal on the housing cover or on the electrical connection door has been broken, there is no further obstacle for the complete or partial removal of the meter cover

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or the electrical connection door, the only evidence that the meter has been broken is the broken one Sealing wire or the seal. Such access to the meter or the electrical connection chamber opens up the possibility of mechanically or electrically the meter at a registration of the full display of the current or to prevent other consumer goods. Because such wires and lead seals are relatively fragile, it is difficult to get the customer's argument. refute that the seal was broken accidentally has been.

The object of the present invention is to provide a security sealing device of the e.ingangs named genus to prevent any unauthorized loosening of two parts to be held together, in particular any unauthorized intervention in counters, reliably displays and an accidental or automatic opening of the safety device under excludes all circumstances.

This object is achieved according to the invention in that the bolt with a weakening zone and after its use in the bores of the parts to be held together is provided with locking means preventing its axial movement which the bolt is breakable at its weakened zone. By this arrangement; is any unauthorized interference with the

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Safety Victory Device for separating those to be held together by it Parts directly connected with a breaking of the bolt at its weakening zone, which only by the action external forces and not by accident.

According to a preferred embodiment of the invention, the bolt is provided on its periphery with a notch into which engage elastically resilient locking means.

The present invention relates in particular to the protection of both the meter hood and the electrical connection door of electrical supply meters, but can of course also be used on other meters or recording or Measurement or display devices are transmitted in which it is essential to prevent unauthorized access to the interior of the chamber to prevent.

Although the invention has a wide scope in this way the security sealing device will then be described with particular reference to electrical utility meters. However, this is only as an application example to understand.

Various embodiments of a security sealing device

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for electrical utility meters are described in the drawings. Show in it:

Fig. 1: A partial section through a conventional embodiment for the protection of electrical supply meters by using a wire and lead seals,

Fig. La: the view A of Fig. 1,

FIG. 2: a partial sectional view of an embodiment of the security sealing device according to FIG Invention for securing the housing hook of an electrical supply meter,

Fig. 2a: the plan view of a spring washer Locking means,

Fig. 3: a conventional embodiment of the fuse the electrical connection door of an electrical supply meter by means of a wire and a Lead seal,

FIG. 4: a sectional view similar to FIG. 3, showing a Security sealing device according to the invention

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represents

FIG. 5: a sectional view, similar to FIG. 4, with

a small modification of the security sealing device,

6: an improved embodiment of the safety sealing device for securing an electrical one Connecting door, and

FIG. 6 a: the view PIP from FIG. 6.

Identical or corresponding parts in the different embodiments are provided with the same reference numbers.

Reference is first made to FIG. 1, the conventional means for holding together a housing cover 10 to a housing base 1? of an electrical supply meter shows. The partial view of FIG. 1 a is the external view of the security sealing device in the direction of arrow A. The housing cover 10 is conventionally fastened to the housing base 12 by means of two screws, one of which is denoted by the reference number 14 in FIG. The screw 14 has a screw head 16 with a cross hole 18 and a slot 20 for the engagement of a screwdriver or other tool

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is provided. The screw 14 leads through a sealing clamp 22, which has two side lugs 24a and 24b, each of which has an opening that leads to a cross-hole 18 in the Screw head 16 is aligned. The bolt 14 extends through a bore 26 in the housing cover 10 and through a bore 28 in the housing base 12, the bore 28 extends up to a recess 30 of hexagonal cross section in the housing base 12. The bolt 14 is in a hexagonal nut 32 which is held in place in the recess 30 by a plug 34 made of e.g. will.

The sealing clamp 22, through which the screw bolt 14 passes, is rotated by its substantially rectangular Shape as well as being prevented from rotating by more than a few degrees hits against the wall of the housing cover 10. After the screw bolt 14 during the assembly of the housing cover 10 has been tightened to the housing base 12, the hexagonal recess 30 prevents rotation of the nut 32. Then a sealing wire, not shown, through the openings in the side extensions 24a and 24b of the sealing clamp and through the hole 18 guided in the screw head 16 and the two ends of the wire is put through a lead seal, which is then sealed by deformation of the lead. The bolt 14 cannot be turned back and the housing cover 10

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cannot be separated from the housing base 12 without breaking the seal.

The improved safety victory device according to the invention is shown in FIG. The lead and wire seal that is connected to the sealing terminal 22 and the screw head 16, is kept unchanged, whereas the screw bolt 14 itself is changed. The bolt 14 has an expansion piece of reduced diameter extending axially from the threaded end of the screw, this expansion piece 36 is provided with one or more annular circumferential notches 38 at its free end. Two such notches 38 are in the Embodiment shown. In addition, the hexagonal Recess 30 in the housing base 12 is a countersink 40 around a relatively low, further recess with a larger cross section to form in the housing base. The bolt 14 in turn carries a hexagonal nut 32, which is in its position in the Setback 30 is held by a plastic plug 34. The screw shaft is between its head 16 and its threaded part intentionally weakened by the provision of a V-shaped circumferential incision 42 at one point on the screw shaft, which leads through the housing cover 10.

When installing the housing cover 10 on the housing base 12, the bolt 14 is used in a conventional manner and with the

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Nut 32 tightened. A flat disk 44 is then placed over the protruding end of the expansion piece 36 of the bolt 14 pushed, until it comes into contact with the countersink 40. Then a spring washer 46 is over the protruding end of the expansion piece 36 of the bolt 14 is pressed. The spring washer 46 has a number of radially inwardly directed teeth 48 which into the closest notch 38 in the expansion piece 36 of the bolt 14 are forced. Although it is possible, only one To provide an annular notch 38, a number of notches are preferably made in the extension piece 36 of the bolt 14) to allow manufacturing changes in e.g. the shape. The spring washer 46 is then in the bottom of the countersink nearest notch 38 wedged. After this, lead and wire seals are conventionally placed on the other end of the Bolt 14 attached.

In order to gain access to the measuring counter, the sealing wire must first be broken and then the bolt 14 must be turned counterclockwise to be turned around. Since the bolt 14 can now no longer be moved axially due to the spring washer 46 and the If the nut 32 cannot rotate in its hexagonal recess 30, the nut 32 and the plastic plug 34 will move in the direction of the countersunk end of the recess 30. Eventually the nut and the plastic plug will reach the extension piece 36 of the bolt 14, which does not come with it

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is provided with a threaded piece and which is of sufficient axial length to receive the nut and plug. A continuation the counterclockwise rotation of the bolt 14 will then have no further effect and the housing cover will remain firmly connected to the housing base 12 as a result of the spring washer 46. Then if any attempt is made should be to separate the housing cover 10 and the housing base 12 from each other forcibly, this tension is on the Transfer spring washer 46. The flat washer 44 behind the spring washer 46 then prevents the inward bending of the Spring washer 46. The teeth 48 of the spring washer 46 are mainly subjected to shear stress and, if the force, the Separating the housing cover and the housing base from each other is sufficient is, the bolt 14 will break at its weakening point 42 and so conclusive evidence of the unauthorized opening of the Measuring device is available. The countersink or recess 40 covers the edges of the spring washer 46 and is on the rear side of the housing socket 12, which in turn is attached to the meter panel is screwed, making it impossible to remove the spring washer 46.

It is intended that such electrical supply meters will be connected to the electricity company with the one screwed onto the housing base 12 To deliver the housing cover, but without attaching the disks 44 and 46, so that during the test acceptance and

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Examination certificate issued by both the seals and the washers the responsible electricity company can be installed. The housing cover can be removed for maintenance of the measuring devices 10 may be required by the electricity company. The intention here is to do this by over-turning the screw bolt 14, e.g. by turning it clockwise, until the screws break at their weakening point 42 and release the housing cover 10. The two halves of the bolt 14 can then easily be removed and replaced with new bolts 14 and washers 44 and 46, respectively.

Figures 3 to 5 show a safety win! Device, which can be used e.g. to secure an electrical connection door of an electrical supply meter.

3 shows the conventional arrangement with the electrical connection door 60 attached to the meter base 62. A bolt 64 extends through a sealing member 66 and then through the door 60 itself in order to come into engagement with a nut 68 which is arranged in a hexagonal recess 70 in the meter base 62. The nut 68 is retained in the recess 70 by a plastic plug 72. The sealing member 66 has a pair of side ears 66a, 66b which have a pair of openings so that a sealing wire can be passed through these openings and through a bore in the screw head 64

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can before it is sealed with a lead seal, as it is already in connection with the sealing device of FIGS and 2 has been described.

FIG. 4 shows an improved safety victory device according to FIG of the present invention. The wire and lead seal is used as before, whereas the screw 64 is now through a round, slotted blend nut 80 is replaced, which also has a cross hole like the screw 64, but is rotatable within the sealing member 66 by the nut, which has a flange part 81 on the side of the sealing member 66 which is opposite the main nut part. A bolt 82 which is threaded at one end to fit into nut 80 and that at the other The end threaded to fit the hexagonal nut 68 is threaded onto the nut 68. The central part of the bolt 82 has a portion 84 of enlarged diameter and of hexagonal cross-section. The central part of the screw bolt 82 also includes a circumferential notch 86, which at the same time forms a recess for the spring washer 88 and secures the weakest portion of the bolt 82 at that point. The electrical connection door 60 is with a Hexagonal recess 90 is provided to receive the hexagonal cross-sectional part 84 of the screw bolt 82. Furthermore is the electrical connection door 60 with a recess 92

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provided, which tightly encloses the spring washer 88 at its outer diameter.

When the equipment fitter connects a meter to a household supply wired, he will first check that the wiring has been carried out correctly. The electrical connection door 60 is then with the hexagonal opening 90 over the hexagonal part 84 of the bolt 82 in position and the. Spring washer 88 pressed over the bolt 82 until it snaps into the notch 86. The unit consisting of the blend nut and the sealing member 66 is then applied to the one end of the bolt 82 is screwed and sealed in the conventional manner with wire and lead seal.

In order to gain access to the electrical connection door, lead and sealing wire must first be broken open and removed so that the nut 80 can be unscrewed from the screw bolt 82. ' However, the spring washer 88 then still holds the Door 60 secured and there the spring washer 88 at the bottom of the recess 92 is tightly secured, it is extremely difficult to remove the spring washer 88. The screw bolt 82 cannot be unscrewed because its hexagonal part 84 is mounted in the hexagonal recess 90 in the door 60 and when it is lifted off the door either breaking the door or the bolt 82 at its notch 86 would cause and thereby

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509812/0710

provides evidence of unauthorized interference with the measuring device. If an authorized person wishes to remove the door, they will grasp the upper threaded part of the screw bolt 82 with pliers or a similar tool and try to bend it, until the bolt will break at its notch 86. Then a new bolt can be attached, since when the door 60 is now lifted, the broken screw bolt can be unscrewed and a new one can be inserted.

The hexagonal cross-sectional portion 84 of the bolt 82 is of course only one way of preventing the Bolt is unscrewed once the door is in place. A square cross-section or with a driving pin provided round diameter can serve as alternatives «Alternatively, a one-piece screw bolt hexagonal head can be used in place of nut 68 and bolt 82 as shown in Fig. 5, wherein the other parts remain the same as in FIG. The method of use with this latter arrangement is identical, whereas once the bolt is broken it cannot be replaced on the spot because the replacement of the Bolt would require removal of the electrical connection door.

Fig. 6 shows an improved security sealing device for

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an electrical connection door. In Fig. 4, the screw bolt is described as it is a part 84 of enlarged diameter and has a hexagonal cross-section that rotates through its insert in a hexagonal recess 90 in the electrical Connection door 60 is prevented. In this way, the screw bolt 82 is screwed into the base 62 in FIG. 4, until it has been finger tightened and then it will turned back a little until two hexagon 84 faces are horizontal lie, which serves as the orientation of the recess 90 in the door 60 when it is attached to it. This ring-shaped setting, to fit the recess 90 over the hexagon 84 is a little critical and therefore not easy to accomplish. Furthermore, the slight turning back of the screw bolt 82 causes the screw bolt 82 to sit somewhat loosely in FIG the nut 68 so that when the door is attached it is also loose. Balancing this does not have an adverse effect on security includes, this fact is not likely to promote trust in this species.

In FIG. 6, the enlarged cross-sectional part 84 of the screw bolt 82 is now of rectangular cross-section, whereby the recess 90 in the door 60 has the cross section shown in FIG. 6a and has two integrally cast, radially inwardly projecting lugs 96 for rotation of the screw bolt 82 as indicated by the dashed lines

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real,

is. In this way, it is no longer necessary to place the rectangular cross-sectional part 84 in an exactly horizontal position to leave the assembly in order to be able to attach the recess 90 over it, since now a tolerance of approximately +40 is tight enough is. The screw bolt can now be adjusted from its tightened position to this position by turning it back slightly. Another extension piece 95 is added to the screw bolt 82 in order to press against a resilient wall in the plug 72 and deform it during the last few tightening turns of the bolt 82. The screw bolt 82 can now be turned back a little to leave the rectangular cross-sectional portion 84 approximately horizontal with the bolt due to the pressure of the extension piece 95 against the plug 72 remains tightened.

The screw bolt 82 in the embodiment of FIG. 6 also differs slightly from the embodiments of FIGS Spring washer 88 engages. In this case, the screw bolt is provided with a circumferentially located V-shaped groove 98 at a point which lies between the enlarged cross-sectional part 84 and the notch 86 for the spring washer 88 .

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509812/0710

Claims (1)

1 / Safety victory device for two parts to be held together, in particular for use in electrical supply meters with a housing hood and one to be held together with it Housing base, which consists of a rigid, elongated bolt with a threaded part, which is to be held together by a hole in each case Parts reaches through and over a zone with enlarged cross-section at one point of its length in one Engagement engages, which is arranged in one of the parts to be held together, characterized in that that the bolt (14, 82, 94) with a Schwächungsz / one (42, 86, 98) and after its use in the bores (26, 30) of the parts (10, 12; 60, 62) to be held together with locking means preventing its axial movement (44, 46, 88) through which the bolt (14, 82, 94) is breakable at its weakening zone (42, 86, 98). 2. Security sealing device according to claim 1, characterized characterized in that the bolt (14, 82, 94) is provided on its periphery with a notch (38, 86) in which the locking means (46, 88) engage. - 18 - 509812/0710 3. Safety victories! Device according to claim 1 or 2, characterized in that the zone (82, 68, 84) has a square, rectangular or polygonal shape with the enlarged cross section. 4. Security sealing device according to claims 1 to 3, characterized in that the seat for the locking means (46, 88) is in a recess (40, 90) is arranged in one of the parts to be held together. 5. Sicherheitssiege! Device according to claims 1 to 4, characterized in that the zone (84) of enlarged cross-section is integral with the bolt (82) is formed and has a shape in relation to the cross-sectional shape of the recess (90) within which the zone (84) is rotatable through an angle of less than 90 degrees. 509812/0710 6ο security sealing device according to claims 1 to 4, characterized in that the zone (32, 68) of the enlarged cross-section from one with the Threaded part of the bolt (14) cooperating nut (32) consists, one part of the two to be held together Parts, e.g. the housing base (12), both with the recess (30) receiving the nut (32) and with the seat of the locking means (44, 46) forming recess (40) is provided. 7. Security sealing device according to claim 6, characterized in that the two recesses (30, 40) for the nut (30) and the locking means (46) of the bolt (14) on the back of the housing base (12) are arranged. 8. Security sealing device according to claims 6 and 7, characterized in that the bolt (14) at its end facing the locking means (46) is provided with a plurality of circumferential grooves (38) in which the locking means (46) engage. -20- 509812/0710 9. Security sealing device according to claim 8, characterized in that the locking means of at least one spring washer (46) with inwardly directed and in the circumferential groove (38) engaging teeth (48) exist. 10. Security sealing device according to claims 4 or 5, wherein the parts to be held together from the base of a electrical supply meter and an electrical connection door of the measuring device exist, thereby characterized in that the electrical connection door (60) both the enlarged zone receiving Has recess (90) as well as the recess (92) forming the seat of the locking means (88). Ho security sealing device according to claim 10, characterized in that the locking means consists of a spring washer (88) which engages in a groove (86) of the bolt (82), which at the same time forms the zone of weakness (86). -21- 509812/0710 12. Safety victory device according to claims 10 or 11, marked by the fact that the End (95) of the bolt (82) within the bore of the Base (62) to compensate for any play occurring between the bolt (82) and the device base (62) can be pressed against elastic spring means (72). 509812/0710 Lee rse i t