WO2021044337A1

WO2021044337A1 - Inspectable padlock

Info

Publication number: WO2021044337A1
Application number: PCT/IB2020/058208
Authority: WO
Inventors: Erik BOEFF
Original assignee: Brady Bv
Priority date: 2019-09-04
Filing date: 2020-09-03
Publication date: 2021-03-11
Also published as: NL1043370B1; EP4026113A1

Abstract

A padlock consisting of an elongated strip of tearable flexible material that can be folded into a loop and fixed into place, while the strip contains an electrical circuit which is broken when the loop is torn and a RFID connected to the electrical circuit which is put in a different logic state when the circuit is broken. The elongated strip with electrical circuit and the RFID are located in the same planar plane together with a self-adhesive zone with a cover on which after removal of the cover the loose end of the elongated strip is fixed to form a loop.

Description

Title

Inspectable padlock

Description

The padlock is predominantly known as a strong metal mechanical lock. It is a lock that essentially connects two eyes by inserting a shackle through said eyes. By anchoring the shackle to a housing connected to the shackle the connection can be secured and unlocked with lock and key.

The padlock in its classic shape has two functions. The first function is that of a mechanical lock for the connection of the two eyes. The generally metal housing with metal shackle is so strong that the connection of the two eyes cannot be broken with bare hands.

The second function is that of visualizing the presence of a lock. The shackle, which is inserted through the eyes, makes it visually easy to recognize. Also from a distance it is visible that the connection is present and intact. This second aspect is often overlooked. However, on the production floor the padlock is often used by mechanics for this reason to demonstrably secure the switches that disable a production machine.

When the padlock however is located outside of a visual sightline the second function is no longer available. Thereby it is not possible for locks out of sight to assure that the connection is intact.

Another disadvantage is that the connection of a classic padlock can only be broken by means of a key. When a lock is to be broken without tools, such as during a fire alarm, a lock with a key is not practical.

Another disadvantage of a classic padlock is that they are relatively heavy and bulky. When only a small or narrow space is available to apply a lock or when the lock is located in a place that is inaccessible with hands, this is disadvantageous.

The invention described below overcomes these disadvantages.

The invention consists of a stacked assembly of very thin and mostly flexible parts, which essentially has the function of a padlock.

In the invention the shackle consists of a flexible strip elongate material (1). This material can be folded or bent into a loop which will function as the shackle of the padlock. The strip material is inserted through two eyes (C) to form the closure of the lock. The housing (2) of the padlock consist, inter alia, of a to an end of the elongate trip attached self-adhesive surface (3) to which the other free end of the flexible strip is fixed. Thus the loop is secured. In a preferred embodiment the self-adhesive surface (3) is folded back on itself to adhere the placement of the elongated strip on the two sides.

The adhesive strength of the self-adhesive zone is so high that the loop consisting of the folded elongated strip (1) can only be broken by tearing through the material of the elongated strip (1). By accurately choosing the tearing strength of the elongated strip (1), the force required to break the connection can be determined. As such it can be determined whether the connection can be broken manually or whether a tool, such as pliers, should be used in case it is desired. Additionally a lower limit for the tearing strength can be set in order to prevent unintentional tearing. By preferably building the elongated strip (1) out of plastic films it is possible to select the tearing strength according to any need. The possibilities for determining the tearing strength of a plastic film are: the choice of the plastic and consequently its basic strength properties, the thickness of the film, chain stretching and thus direction-dependent tear strength of the film, the orientation of that stretching, weakening by perforation, notching effect of cuts or other types of mechanical interventions.

In a preferred embodiment the elongated strip (1) consists essentially of a laminate of two amorphous PET films with a thickness between 50 and 90 microns and a low chain orientation in the longitudinal direction of the elongated strip. As such a tearing strength between 50 and 150 Newton is obtained which is both a tearing strength that can be applied manually as well as a tearing strength that prevents unintentional tearing.

In a different preferred embodiment the elongated strip (1) consists of the merger of two oriented films of HDPE, PP, or PET whose chain orientations doe not coincide or are parallel, but are at an angle with respect to each other. Such a configuration is cannot be torn manually and will require a tool in order to be broken.

On the elongated strip (1) an electrical circuit (4) is arranged in the shape of a long and minimally wide loop, which essentially covers the entire length of the elongated strip (1). The electrical circuit (4) preferably is mechanically weak with respect to the mechanical strength of the elongated strip (1). By breaking the elongated strip (1) also the electrical circuit (4) will be broken.

Connected to the elongated strip (1) with its electrical circuit (4) is a zone located in the same planar plane as the elongated strip (1) and is hereinafter referred to as the housing (2). The housing (2) consists of a self-adhesive surface (3) to which the end of the flexible strip (1) is positioned and anchored and a surface on which an RFID (5) is mounted.

The RFID (5) consists of a programmable logic processing unit (7), an antenna (6) and an input for the electrical circuit (8). The electrical circuit in (4) the elongated strip (1) and the RFID (5) are interconnected. When the electrical circuit is broken by tearing the elongated strip, the logic processing unit (7) of the RFID is set in a different state. The state of the RFID (5) can be read remotely. Thereby it is possible to inspect the status of the padlock: intact or broken, even if the padlock is out of sight.

In a preferred embodiment the antenna of the RFID is capable of using more than one frequency for its communication with the outside world. To this end the antenna (6) is shaped to have reduce resonance in order to process a broader spectrum of frequencies. This makes it possible to deploy the padlock in multiple domains while using different communication frequencies.

In a further preferred embodiment the electrical circuit (4) and the RFID with antenna (5) are mounted between two coverings layers (9 and 12), each with its own inwardly facing adhesive layer (10 and 12). Elongated strip (1) and housing (2) thus are both part of the same sandwich construction, which allows to further process the semi-finished product as a roll in a later stage of production.

The sandwich makes it possible to enclose the electrical circuit (4) and RFID with antenna (5) in three dimensions (top, bottom, and sideways) with adhesive and thus isolate it from the outside world. The nature and extent of the insulation can be determined by selecting the material properties of the adhesive.

In a preferred embodiment the adhesive is water-repellent and the adhesive protects thus protects the components against the effects of, for example, rain or splash water. In a further preferred embodiment the adhesive also has a barrier for water vapor and thus protects the adhesive from corrosion.

In a further preferred embodiment the adhesive has electrically insulating properties and the adhesive thus protects the RFID (5) against unintentional leakage currents.

In a further preferred embodiment the adhesive has thermal insulating properties and thus protects the RFID (5) against unintentional temperature shocks.

In a preferred embodiment adhesives are used having a base material styrene-butadiene block polymer which insulates both electrically and thermally, as well as being water- repellent.

In a preferred embodiment the electrical circuit (4) and the RFID (5) are pre-mounted on a plastic film that is mounted between two plastic films, each with its own inward-facing adhesive layer. The thickness of the RFID is also between the 30 and 50 microns. Both aforementioned elements make it possible to supply the sub-assembly of electric circuit (4) and RFID (5) as a roll, which makes it possible to further process the semi-finished product with other sub-assemblies supplied on a roll in a later stage of production.

In a further preferred embodiment the elongated strip (1) and housing (2) consist of a sandwich of a wide (13) and a narrow strip of covering (9), both provided with an adhesive. A part of the wide strip with adhesive (12) is not covered by the narrow strip (9). Said wide strip (13) has a permanent sticky adhesive (12). By covering the uncovered part with a protective sheet (14) which does not adhere to the adhesive (12), a zone for anchoring (3) of the end of the elongated strip (1) has been created which can be made ready for use by removing the protective sheet.

In a further preferred embodiment the sandwich with elongated strip (1), RFID (5) and anchoring zone (3) thereon is formed into a practical geometric shape by means of punching out.

In a preferred embodiment the electrical circuit (4) and RFID (5) are punched out with a contour that is larger than the outer dimensions of electrical circuit (4) and RFID (5). As such, said components are, in all three dimensions, surrounded by adhesive and are isolated from the outside world.

In a further preferred embodiment the elongated strip (1) is punched to a width that is compatible with the size of the eyes (C) that will connect the elongated strip (1) in its function as a shackle.

List of figures

Figure 1

Top view of padlock Herein, i is an elongated strip, i is the housing and 3 a self-adhesive surface.

Figure 2

Closing the shackle

Herein, 1 is the elongated strip, 2 is the housing, 3 is a self-adhesive surface and C are two eyes.

Figure 3

Top view of semi-finished product

Herein, 1 is an elongated strip, 2 is the housing, 3 is an adhesive pad, 4 is an electrical circuit, 5 is an RFID, 6 is an antenna of the RFID, 7 is the logic processing unit, 8 is the input for the electrical circuit and the line AB is a line along which the cross-section of Figure 4 is drawn.

Figure 4

Cross-section of padlock along line AB Herein, 9 is a top covering, 10 an adhesive layer of the top covering, 11 the layer containing the electronic components, 12 the adhesive layer of the underlying covering, 13 the underlying covering and 14 a protective sheet.

Claims

1. A padlock consisting of an elongated strip (l) of tearable flexible material that can be folded into a loop and fixed into place, characterized in that the strip contains an electrical circuit (4) which is broken when the loop is torn and an RFID (5) connected to the electrical circuit (4) which is put in a different logic state when the circuit (4) is broken.

2. A padlock according to claim 1, wherein the elongated strip with electrical circuit (4) and the RFID (5) are located in the same planar plane together with a self-adhesive zone (3) with a protective sheet (14) on which after removal of the protective sheet (14) the loose end of the elongated strip (1) is fixed to form a loop.

3. A padlock according to claim 2, wherein the self-adhesive zone (3) has such an adhesive strength compared to the tear strength of the elongated strip (1), that the loop can only be broken by tearing the material of the elongated strip (1).

4. A padlock according to claim 1, wherein the elongated strip (1) consists of a sandwich of two strokes of protective flexible material (9 and 13) with inwardly facing adhesive layers (10 and 12), between which both the electrical circuit (4) and the RFID (5) are positioned, characterized in that the two strokes (9 and 13) have unequal width, such that the adhesive layer (12) on one side both adheres to one side of the sandwich and is also free to form the adhesive zone (3) to fix the loose end of the elongated strip (1).

5. A padlock according to claim 1, wherein both the electrical circuit (4) and the RFID (5) are preassembled on a plastic foil, which are positioned between two strokes of protective flexible material (9 and 13) with inwardly facing adhesive layers (10 and 12).

6. A padlock according to claim 1, wherein both the electrical circuit (4) and the RFID (5) are positioned between two strokes of protective flexible material (9 and 13) with inwardly facing adhesive layers (10 and 12) and are punched out with a contour that is larger than the outside dimensions of the electrical circuit (4) and RFID (5).

7. A padlock according to claim 3, wherein the RFID (5) and the electrical circuit (4) are enclosed in three dimensions by an adhesive layer.

8. A padlock according to claim 3, wherein the adhesive layers (10 and 12) are impermeable to liquid or gaseous water.

9. A padlock according to claim 3, wherein the adhesive layers (10 and 12) are electrically insulating.

10. A padlock according to claim 3, wherein the adhesive layers (10 and 12) are thermally insulating.