GB2591083A

GB2591083A - Safety harness system

Info

Publication number: GB2591083A
Application number: GB2000024.6A
Authority: GB
Inventors: Shelton Paul; Jester Tony; Campbell Andrew
Original assignee: Cape Industrial Services Ltd
Current assignee: Cape Industrial Services Ltd
Priority date: 2020-01-02
Filing date: 2020-01-02
Publication date: 2021-07-21
Also published as: GB202000024D0

Abstract

A safety harness system 10 for use at an elevated work site, the safety harness system 10 comprising a harness 12 configured to be worn and a safety hook 14 coupled to the harness 12, the safety hook 14 comprising a sensing device 16 configured to generate a signal indicative of the presence and/or absence of an object in a space 18 defined by the hook. Wherein the device triggers an alert or alarm unless an object is determined as being present in the space 18 defined by the safety hook 14.

Description

Safety Harness System

FIELD

The present invention relates to a safety harness system, more particularly, but not exclusively, a safety harness system for use at an elevated work site. The invention also relates to a kit of parts for a safety harness and a safety hook apparatus.

BACKGROUND

There are a variety of activities that require people to operate at elevated heights, such as construction work, tree surgery, high-rise building maintenance or climbing. When performing such activities, there is a risk of serious injury or death by falling -the Health and Safety Executive recorded 40 deaths in the UK due to falls from a height in the 2018/2019 reporting period.

A variety of safety harnesses have been developed to reduce the chances of falling from an elevated height. Typical safety harnesses for elevated working include two safety hooks connected to a wearable harness. This arrangement allows the harness wearer to move around whilst staying attached to a safety structure. For example, when climbing a ladder the safety hooks can be moved up the ladder rungs one at a time, which means that at least one safety hook is always attached.

Typical safety hooks used in such safety harnesses include an opening and a spring loaded clip biased to cover the opening i.e., the clip is biased to a shut position. A hook can be easily attached to an object by pushing the object against the clip and through the clipped opening. Once an object is inside the space defined by the hook, the spring pushes the clip to the closed positon, which prevents the object from being released from the hook by accident.

When used properly, two-hook safety harnesses greatly reduce the risks of injury or death due to falling. However, such harnesses rely on the harness wearer following the correct safety procedure (i.e. having at least one hook attached to an object, such as a scaffold pole, at all times). This means that safety can be compromised when a person either forgets to attach a hook, or willingly chooses not to attach a hook to a safety structure (e.g. to save time climbing a ladder).

The present invention seeks to overcome or at least mitigate one or more problems associated with the prior art.

SUMMARY

According to a first aspect of the invention, a safety harness system is provided for use at an elevated work site, the safety harness system comprising: a harness configured to be worn; and a safety hook coupled to the harness, the safety hook comprising a sensing device configured to generate a signal indicative of the presence and/or absence of an object in a space defined by the hook.

In other words, the safety hook comprises a sensing device which is configured to detect whether an object, such as a scaffold pole or ladder rung, is present in or absent from the space defined by the hook.

When working at an elevated work site, a safety hook should always be attached to an object, such as a scaffold pole or ladder rung, so that the person wearing the harness is prevented from falling further than the length of the coupling between the safety hook and the harness.

Systems disclosed herein provide a means for determining if a safety hook is connected to an object (e.g. a scaffold pole or ladder rung). This information may be useful for monitoring whether a person wearing said harness is at risk of a fall or other dangerous incident, and could be used to improve the safety of a person wearing said harness.

In exemplary embodiments, the safety harness system is configured to determine the presence and/or absence of an object in the space defined by the hook based on the signal generated by the sensing device, and to trigger an alert unless an object is determined as being present in the space defined by the safety hook.

By triggering an alert, the person wearing the harness (or a supervisor/person responsible for the harness wearer) is made aware that the safety hook is not attached to an object (e.g. a scaffold pole or ladder rung). This encourages the harness wearer to attach the safety hook to a safety structure, thereby reducing the likelihood of a fall or other dangerous incident.

In exemplary embodiments, the safety harness system comprises two safety hooks, each comprising a sensing device configured to generate a signal indicative of the presence and/or absence of an object in a space defined by the respective hook.

Advantageously, having two (or more) safety hooks allows the user to detach one safety hook from a support structure, while the second safety hook remains attached to the support structure. This allows the user to move around safely (e.g. to climb to a higher rung of a ladder).

In exemplary embodiments, the safety harness system is configured to determine the presence and/or absence of an object in the space defined by the respective hooks based on the signals generated by the respective sensing devices, and to trigger an alert unless an object is determined as being present in the space defined by at least one of the safety hooks.

This allows the user to detach one safety hook from a support structure without an alert being generated, provided that the second hook remains attached to an object (e.g. a scaffold pole). This allows the user to move around safely, without unnecessary alerts providing an annoyance or distraction.

In exemplary embodiments, the safety harness system further comprises an alerting device having an alerting state in which an alert is output from the alerting device, and an idle state in which no alert is output from the alerting device.

In exemplary embodiments, the safety harness system further comprises a processor for determining the presence and/or absence of an object in the space defined by the or each hook based on the signal generated by the respective sensing device. In exemplary embodiments, the processor is configured to set the alerting device to the idle state when the processor determines that an object is present in the space defined by the or at least one hook, and to set the alerting device to the alerting state otherwise.

Such a system is configured to provide an alert when none of the safety hooks present are attached to an object. This may act as a reminder to the user to attach at least one safety hook (e.g. to a scaffold pole), and hence reduce the risk of accidental falling (e.g. from an elevated construction site).

In some embodiments, the alerting device may be capable of alerting a supervisor, who may instruct the user to attach their safety hook. This may further incentivise the user to keep their safety hook clipped in, to prevent being prompted by their supervisor.

In exemplary embodiments, the or each sensing device comprises two or more detection regions, wherein the system is configured to determine whether an object (e.g. a scaffold pole) is entering or leaving the space defined by the hook based on the order in which the object (e.g. a scaffold pole) passes through the detection regions.

In exemplary embodiments, the sensing device comprises two or more sensors, each having an associated detection region. For example, a first sensor comprises a first detection region and a second sensor comprises a second detection region.

In some embodiments, a single sensor comprises a first and second detection region.

In exemplary embodiments, the detection regions are distributed along a path of travel that is followed by an object as it is moved into or out of the space defined by the hook.

In exemplary embodiments, the sensing device (e.g. the first sensor) is configured to generate a signal indicative of the presence and/or absence of an object in the first detection region. Similarly, the sensing device (e.g. the second sensor) is configured to generate a signal indicative of the presence and/or absence of an object in the second detection region.

In exemplary embodiment, the first and second detection regions are positioned along the path of travel such that an object being moved into the space defined by the hook passes through the first detection region and then the second detection region.

For example, when the sensing device detects that an object (e.g. scaffold pole) passes through the first detection region followed by the second detection region, the safety harness system can determine that an object (e.g. scaffold pole) is entering the space defined by the hook. In other words, the hook is being clipped onto an object.

Conversely, when the sensing device detects that an object passes through the second detection region followed by the first detection region, the safety harness system can determine that an object (e.g. scaffold pole) is leaving the space defined by the hook. In other words, the hook is being unclipped from an object.

In exemplary embodiments, the or each safety hook comprises a body comprising an opening through which an object can be introduced into and/or removed from the space defined by the hook, the hook further comprising a clip coupled to the body, wherein the clip is configured to be moveable between a closed state in which the clip covers the opening, and an open state in which a free end of the clip protrudes into the space defined by the hook such that the opening is not covered by the clip, and wherein the sensing device is provided in the clip and/or the body It will be appreciated that the path of travel of the object as it is moved into or out of the space defined by the hook passes through the opening in the body.

In some embodiments, the sensing device is located in the clip and/or the body such that it does not protrude into the space defined by the hook, which prevents it from being hit or damaged by an object placed therein (e.g. a scaffold pole).

In exemplary embodiments, the clip is biased towards the closed state. In this way, the clip is configured to cover the opening unless the clip is pushed to overcome the biasing force. This prevents an object (e.g. a scaffold pole) within the space defined by the hook from accidentally passing through the opening, which could result in an unsafe state for the harness wearer.

In exemplary embodiments, a clearance between the clip and the body (i.e. across the opening) when the clip is in the open state is in the range of lmm to 5mm greater than the width of the object intended for insertion through the opening (e.g. a scaffold pole).

In exemplary embodiments, the clearance is in the range of 2mm to 3mm greater than the width of the object intended for insertion through the opening (e.g. a scaffold pole).

Such a clearance of lmm to 5mm ensures that the object passes close enough to the sensing device in the clip and/or the body, so that it can be detected by the sensing device.

This reduces the chance of false negatives, which would be associated with a substantially larger clearance. Further, such a clearance enables sensing devices having a reduced range to be used.

In exemplary embodiments, the clip comprises a portion having a U-shaped cross-section defining a recess, wherein the sensing device is provided in said recess of the clip.

In this way, as an object (e.g. a scaffold pole) moves into or out of the space defined by the hook, via the opening, the object moves past the clip (which is in the open state) and therefore past the sensing device located in the U-shaped portion of the clip. This ensures that the object moves close enough to the sensing device to be detected.

Locating the sensing device in the recess of the U-shaped portion also serves to protect the sensing device from damage.

In exemplary embodiments, the clip comprises one or more apertures through which the sensing device can detect the presence and/or absence of an object.

By providing one or more apertures in the clip, the sensing device is able to detect the presence of an object close to the clip, without detecting the surface of the clip itself. In other words, the one or more apertures reduce the occurrence of false-positives.

In exemplary embodiments, the sensing device comprises two or more sensors and an aperture corresponding to each sensor.

In exemplary embodiments, the sensing device comprises an inductive sensor. Inductive sensors are also known as magnetic sensors.

As will be appreciated by those skilled in the art, there are a wide range of off-the-shelf inductive sensors which may be suitable for providing the sensing device. This reduces the cost and complexity of designing and manufacturing the system.

Furthermore, since inductive sensors only detect conductive objects, this system prevents or reduces false alarms. For example, this system may prevent or reduce a user generating a false alarm by attaching the hook to their body. In a construction environment, the use of a sensor that only detects conductive objects encourages the user to attach a hook to a metal safety object or structure, such as scaffold pole or ladder rung.

In exemplary embodiments, each safety hook is made from a non-ferrous material. Since inductive sensors are more sensitive to ferrous metals, having a non-ferrous hook allows the sensor to be tuned so that is capable of detecting a ferrous object within the space defined by the hook (e.g. a steel scaffold pole) without detecting the presence of the hook itself.

In exemplary embodiments, the inductive sensor comprises a wire coil and the sensor is configured to detect the presence of a metal object by supplying current to the coil, so that a magnetic field is induced and intersection of the magnetic field by a metal object changes the impedance of the coil.

In exemplary embodiments, said safety hook comprises an inner perimeter comprising a locating region configured for receiving an object such as a scaffold pole, wherein the wire coil is positioned on a portion of the inner perimeter spaced away from the locating region and/or opening of the hook.

Since an object that a hook is attached to (e.g. a scaffold pole) makes contact with the inner perimeter of the body of the hook, locating the sensor on this inner perimeter allows the presence of said object to be easily detected.

Locating the sensor away from where an object would rest reduces the likelihood of the wire coil getting in the way, or being snagged by an object as the hook is 15 attached/detached.

In exemplary embodiments, the sensing device comprises a capacitive sensor.

As will be appreciated by those skilled in the art, there are a wide range of off-the-shelf capacitive sensors which may be suitable for providing the sensing device. This reduces the cost and complexity of designing and manufacturing the system.

In exemplary embodiments, the capacitive sensor comprises two conductive electrodes, wherein, in use, a voltage is supplied to the conductive electrodes so that an electric field is provided therebetween, and wherein intersection of the electric field by a conductive object (for example a scaffold pole) changes the capacitance of said electrodes.

In this way, the capacitive sensor is configured to generate a signal indicative of the presence or absence of an object within the space defined by the respective hook, such as a scaffold pole, ladder rung or other conductive support structure.

In some embodiments, the conductive electrodes are provided in a substrate. In some embodiments, the substrate is made of plastic.

In exemplary embodiments, the space defined by the hook is defined by an inner perimeter of the hook, wherein the capacitive sensor is attached to at least a portion of said inner perimeter.

By locating the sensor on the inner perimeter of the body of the hook, it is positioned proximal where an object (e.g. a scaffold pole) is likely to rest, thereby facilitating the operation of the sensor.

This arrangement protects the conductive electrodes from damage, at least to some degree. In addition, since an object that a hook is attached to (e.g. a scaffold pole) is likely to make contact with at least some portion of the inner perimeter of the body of the hook, locating the sensor on this inner perimeter facilitates detection of said object.

In exemplary embodiments, the range and/or sensitivity of the sensing device is tuned for detection of a scaffold pole in the space defined by the hook. In this way, the system is configured to be suitable for use on construction sites, where workers typically connect their safety hooks to scaffold poles.

In exemplary embodiments, the sensing device is formed of a durable and/or water-resistant material. In this way, the sensing device is less likely to be damaged when operating in typical environments (such as construction sites). This increases the longevity of the sensing device.

In exemplary embodiments, the sensing device may comprise any suitable proximity sensor.

In exemplary embodiments, the safety harness system further comprises an energy storage device for providing power to the sensing device, and/or the or a processor and/or the or an alerting device.

Having an energy storage device (e.g. a battery) allows the safety harness system to be a standalone system with no external power wires required. This makes it suitable for use on construction sites or other safety-critical environments, in which power cables running through the site could pose a safety risk.

In exemplary embodiments, the or each safety hook is coupled to the harness via a lanyard comprising a shock absorbing device.

In the case of a fall, the shock absorbing device slows the user down gradually. This reduces the chance of injury to the user (such as whiplash), as well as reducing the chance of tearing or snapping of any straps or buckles of the harness system.

In exemplary embodiments, the safety harness system further comprises a central unit housing the or an energy storage device, and/or the or an alerting device and/or the or a processor.

It may be desirable to isolate these electrical components from the environment (e.g. to avoid damage due to water, dirt, dust or other contaminants). Housing some or all of these electrical components in one central unit is a more efficient arrangement (in terms of size, materials and cost) than isolating each of the components from the environment individually.

In exemplary embodiments, the or each safety hook comprises a receiving portion (e.g. a groove or other recess) configured to receive the sensing device therein.

In this way, the shape of the safety hook can be optimised for receiving the sensing device (e.g. preventing the sensing device from protruding significantly from the inner perimeter of the body of the hook). This reduces the likelihood of damage to the sensing device (e.g. via catching on an object when the hook is attached to it).

In exemplary embodiments, the alerting device comprises one or more of: a light source, e.g. at least one LED; an audio alerting device; a vibration device; or a wireless transmitter configured to transmit alerts to a phone or other computing device.

In this way, the user and/or a supervisor may be alerted to the fact that the user is not attached to a safety structure via a safety hook.

The use of a low power light source such as LEDs increases the length of time that the safety harness may be used before recharging or replacement of the energy storage device is required. This is particularly important for construction work, where users may be required to wear the safety harness for an entire work shift.

Light-emitting diodes (LEDs) have numerous advantages such as: lower power demand, long lifetime, small size and physical robustness. All of these advantages make LEDs particularly suitable for the alerting device of the safety harness system disclosed herein.

By using a wireless transmitter, a supervisor may receive a call or text message alerting them to an unsafe condition. This allows the supervisor to instruct the user to attach a safety hook (e.g. via telephone or in person). Advantageously, this may act as a further deterrent to users who may be tempted violate safety protocols by failing to attach their safety hooks.

In exemplary embodiments, the light source is provided on the harness such that it is positioned at a user's back when the harness is worn.

According to a second aspect of the invention, a kit of parts for providing a safety harness system for use at an elevated work site is provided, the kit comprising at least one sensing device configured for attachment to a safety hook, wherein the or each sensing device is configured to generate a signal indicative of the presence and/or absence of an object in a respective predetermined area proximal the sensing device.

Such a kit of parts may be suitable for retrofitting to an existing safety harness (e.g. by bonding the sensor to a safety hook).

In exemplary embodiments, the kit of parts further comprises an alerting device having an alerting state in which an alert is output from the alerting device, and an idle state in which no alert is output from the alerting device.

In exemplary embodiments, the kit of parts further comprises a processor for determining the presence and/or absence of an object in the or each predetermined area based on the signal generated by the respective sensing device; wherein, the processor is configured to set the alerting device to the idle state when the processer determines that an object is present in the respective predetermined area proximal the or at least one sensing device, and to set the alerting device to the alerting state otherwise.

Such a kit may be fitted to an existing safety harness to provide an alert when no safety hook is attached to an object. This acts as a reminder to the user to attach at least one safety hook (e.g. to a scaffold pole), and hence reduce the risk of accidental falling (e.g. from an elevated construction site).

Furthermore, the alerting device may be capable of alerting a supervisor, who may instruct the user to attach their safety hook. This may further incentivise the user to keep their safety hook attached to a safety structure, to prevent being prompted by their supervisor.

In exemplary embodiments, the alerting device and the processor may be contained within a central unit configured for attachment to a harness (e.g. via a clip).

In exemplary embodiments, the kit of parts further comprises at least one safety hook, the or each safety hook comprising the respective sensing device.

By including one or more safety hooks with sensing devices, it may be more simple to retrofit the kit of parts to an existing harness, since there is no need to find a means for securing the sensors to an existing safety hook (e.g. via bonding).

In exemplary embodiments, the kit of parts comprises two safety hooks coupled to a shock-absorbing lanyard configured for attachment to a harness, wherein each safety hook comprises a sensing device configured to generate a signal indicative of an object being present in the space defined by the hook in use.

By including two safety hooks, the user may move around whilst always keeping one hook attached to a safety structure. This provides improved safety. By coupling the safety hooks to a shock-absorbing lanyard configured to attachment to a harness, the kit may be simply attached to a harness (e.g. via a clip on the lanyard). Furthermore, having a shock-absorbing lanyard prevents sudden stopping in the event of a fall, which limits the chances of whiplash or other injuries.

According to a third aspect of the invention, a safety hook apparatus for a safety harness system for use at an elevated work site is provided, the safety hook apparatus comprising at least one safety hook, the or each safety hook comprising a sensing device configured to generate a signal indicative of an object being present and/or absent in a space defined by the respective hook.

In exemplary embodiments, the safety hook apparatus comprises two safety hooks coupled to a shock-absorbing lanyard configured for attachment to a harness, wherein each safety hook comprises a sensing device configured to generate a signal indicative of an object being present and/or absent in the space defined by the respective hook.

By including two safety hooks, the user may move around whilst always keeping one hook attached to a safety structure. This provides improved safety. By coupling the safety hooks to a shock-absorbing lanyard configured for attachment to a harness, the safety hook apparatus may simply be attached to a harness (e.g. via a clip on the lanyard).

Furthermore, having a shock-absorbing lanyard prevents sudden stopping in the event of a fall, which limits the chances of whiplash or other injuries.

In exemplary embodiments, the safety hook apparatus further comprises an alerting device having an alerting state in which an alert is output from the alerting device, and an idle state in which no alert is output from the alerting device.

In exemplary embodiments, the safety hook apparatus further comprises a processor for determining the presence and/or absence of an object in the respective space defined by the or each hook based on the signal generated by the respective sensing device. In exemplary embodiments, the processor is configured to set the alerting device to the idle state when the processor determines that an object is present in the space defined by the or at least one hook, and to set the alerting device to the alerting state otherwise.

Advantageously, such a safety hook apparatus may be fitted to an existing safety harness to provide a means of alerting when no safety hook is attached to an object. This acts as a reminder to the user to attach at least one safety hook (e.g. to a scaffold pole), and hence reduce the risk of accidental falling (e.g. from an elevated construction site).

Furthermore, the alerting device may be capable of alerting a supervisor, who may instruct the user to attach their safety hook. This may further incentivise the user to keep their safety hook attached to a safety structure, to prevent being prompted by their supervisor. 20 In exemplary embodiments, the alerting device and/or the processor may be configured for attachment to a harness (e.g. via a clip). In some embodiments the alerting device and/or the processor may be coupled to the lanyard. For example, the alerting device and the processor may be housed within a central unit for attachment to the harness and/or lanyard.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are now described by way of example only with reference to the accompanying drawings, in which: Figure 1 is a schematic of a safety harness system according to an embodiment; Figure 2 is a schematic of a safety harness system according to an alternative 35 embodiment; Figure 3 is a more detailed schematic of the electrical components of the safety harness system of Figure 1 or Figure 2; Figure 4 is a side view of a safety hook with a clipped opening for use with the safety harness system of Figure 1; Figure 5a is a cross-sectional view of the clip of the safety hook of Figure 4; Figure 5b is a front view of the clip of the safety hook of Figure 4; Figure 6 is a side view of a safety hook with a capacitive sensor for use with the safety harness system of Figure 2; Figure 7 is a cross-section through the hook of Figure 6; Figure 8 is a cross-section through an alternative safety hook for use with the safety harness system of Figure 2, having a capacitive sensor; Figure 9 is a side view of a safety hook with an inductive sensor for use with the safety harness system of Figure 2; and Figure 10 is a plan view of the safety hook of Figure 9.

DETAILED DESCRIPTION

Referring to Figure 1, a safety harness system is indicated generally at 10. The safety harness system 10 includes a harness 12 configured to be worn and a safety hook 14 coupled to the harness 12. The safety hook 14 includes a sensing device 16 configured to generate a signal indicative of the presence and/or absence of an object in a space 18 defined by the hook 14.

In other words, the safety hook 14 comprises a sensing device which is configured to detect whether an object, such as a scaffold pole or ladder rung, is present in or absent from the space 18 defined by a perimeter 62 of a body 15 of the hook 14.

Such a system provides a means for determining if a safety hook 14 is connected to an object (e.g. a scaffold pole or ladder rung). This information may be useful for monitoring whether a person wearing said harness 12 is at risk of a fall or other dangerous incident, and could be used to improve the safety of a person wearing said harness 12.

The safety harness system 10 is configured to determine the presence and/or absence of an object in the space 18 defined by the hook 14 based on the signal generated by the sensing device 16, and to trigger an alert unless an object is determined as being present in the space 18 defined by the safety hook 14.

By triggering an alert, the person wearing the harness 12 (or a supervisor/person responsible for the harness wearer) is made aware that the safety hook 14 is not attached to an object (e.g. a scaffold pole or ladder rung). This encourages the harness wearer to attach the safety hook 14 to a safety structure, thereby reducing the likelihood of a fall or other dangerous incident.

In the embodiment illustrated in Figure 1, the sensing device 16 is provided in a clip 17 of the hook, as will be described in more detail in relation to Figure 4 below. Since an object (e.g. scaffold pole) has to pass the clip 17 on its path into or out of the space defined by the hook 18, this increases the chance that the object passes the sensing device 16, and is therefore detected by the sensing device 16.

In the embodiment illustrated in Figure 1, the safety harness system 10 includes two safety hooks 14. Each safety hook 14 includes a sensing device 16 configured to generate a signal indicative of the presence and/or absence of an object in a space 18 defined by the respective hook 14.

Advantageously, having two (or more) safety hooks 14 allows the user to detach one safety hook 14 from a support structure, while the second safety hook 14 remains attached to the support structure. This allows the user to move around safely (e.g. to climb to a higher rung of a ladder).

In alternative embodiments, the safety harness system 10 may include only one safety hook 14 or more than two safety hooks 14, e.g. three or four safety hooks.

As will be described in more detail below, the safety harness system 10 is configured to determine the presence and/or absence of an object in the space 18 defined by each hook 14 based on the signals generated by the respective sensing devices 16. The safety harness system 10 is configured to trigger an alert unless an object is determined as being present in the space 18 defined by at least one of the safety hooks 14.

This allows the user to detach one safety hook 14 from a support structure without an alert being generated, provided that the second hook 14 remains attached to an object (e.g. a scaffold pole). This allows the user to move around safely, without unnecessary alerts providing an annoyance or distraction.

In the embodiment illustrated in Figure 1, each safety hook 14 is coupled to the harness 12 via a lanyard 20. The lanyard 20 includes a shock absorbing device 22. In the case of a fall, the shock absorbing device 22 slows the user down gradually. This reduces the chance of injury to the user (such as whiplash), as well as reducing the chance of tearing or snapping of any straps or buckles of the harness system. Any suitable shock absorbing device may be used, as will be understood by those skilled in the art.

In alternative embodiments, the safety hooks 14 may be coupled individually to the harness 12 via respective shock absorbing devices 22, rather than via a lanyard 20.

In exemplary embodiments, the sensing devices 16 are made from a durable and/or water-resistant material. In this way, the sensing device 16 is less likely to be damaged when operating in typical environments (such as construction sites). This increases the longevity of the sensing device.

Referring to Figure 2, an alternative safety harness system is indicated at 110.

Corresponding components between the safety harness system of Figure 1 are labelled with the prefix "1", and only differences of the embodiment of Figure 2, as compared to Figure 2, are discussed below for the sake of brevity.

In the embodiment illustrated in Figure 2, the sensing devices 116 are located on an inner perimeter 162 of the body 115 of the hook 114, rather than in the clip 117. This inner perimeter 162 corresponds to the position where an object (e.g. scaffold pole) is likely to be positioned with respect to the hook 114, in use. Therefore, this may reduce the chance of false negatives (i.e. not detecting that the hook 114 is attached to an object).

Referring to Figure 3, the electrical components of the safety harness systems 10, 110 are shown in more detail. The reference numerals of Figure 3 correspond to those of Figure 1, but this schematic is also applicable to the safety harness system 110 of Figure 2.

The safety harness system 10 includes an alerting device 24. The alerting device 24 has an alerting state in which an alert is output from the alerting device 24, and an idle state in which no alert is output from the alerting device 24.

The safety harness system 10 includes a processor 26 for determining the presence and/or absence of an object in the space 18 defined by each hook 14 based on the signal generated by the respective sensing device 16. The processor 26 is configured to set the alerting device 24 to the idle state when the processor 26 determines that an object is present in the space 18 defined by at least one hook 14, and to set the alerting device 24 to the alerting state otherwise.

The safety harness system 10 includes an energy storage device 28 (e.g. a battery) for providing power to the sensing device 16, the processor 26 and the alerting device 24.

Having an energy storage device 28 (e.g. a battery) allows the safety harness system 10 to be a standalone system with no external power wires required. This makes it suitable for use on construction sites or other safety-critical environments, in which power cables running through the site could pose a safety risk.

In the embodiment illustrated in Figure 3, the safety harness system 10 includes a central unit 30 housing the energy storage device 28, the alerting device 24 and the processor 26. It may be desirable to isolate these electrical components from the environment (e.g. to avoid damage due to water, dirt, dust or other contaminants). Housing some or all of these electrical components in one central unit 30 is a more efficient arrangement (in terms of size, materials and cost) than isolating each of the components from the environment individually.

In exemplary embodiments, the central unit 30 is positioned on a rear portion of the harness 12, so that it does not get in the way of the harness wearer (e.g. if they are carrying objects close to the front or side of the harness). In the case where the alerting device 24 is a light source (e.g. LED) and is part of the central unit 30, positioning this on the rear of the harness helps to increase the visibility of the alerting device 24. For example, this reduces the likelihood of objects carried in front of the user obstructing the view of the alerting device 24.

In alternative embodiments, the energy storage device 28, the alerting device 24 and the processor 26 may be housed separately, or only some of the listed components may be housed in a central unit 30.

Referring again to Figure 3, the electrical components of the system are connected via communication and/or power cables, represented as solid lines. Each line represents one or more power cables and/or one or more signal cables. The central unit 30 includes a socket 32 for connecting the processor 26 and the energy storage device 28 to the sensing devices 16. The sensing devices 16 are connected to a plug 34 configured for engagement with the socket 32.

In alternative embodiments, the sensing devices 16 may be connected to a socket 32 and the central unit 30 may include a plug 34 configured for engagement with the socket 32.

In other embodiments, a different type of connector arrangement may be used to connect the sensing devices 16 to the processor 26 and energy storage device 28. In yet further embodiments, the system may not include a plug 34 and socket 32 arrangement and the sensing devices 16 may be wired directly to the processor 26 and energy storage device 28. In some embodiments, the sensing devices 16 may communicate wirelessly with the processor 26.

In the embodiment illustrated in Figure 3, a single plug 34 and socket 32 arrangement (e.g. a multiway electrical connection) is provided for both transferring power and signals to/from the sensing devices 16 and for charging the energy storage device 28.

In alternative embodiments, separate plug 34 and socket 32 arrangements may be provided for connecting the sensing devices 16 to the processor 26 and for charging the energy storage device 28. In yet further embodiments, the energy storage device 28 may be replaceable (e.g. via opening of the central unit 30) rather than chargeable.

In some embodiments, the alerting device 24 is an light-emitting diode (LED). The use of a low power light source such as LEDs increases the length of time that the safety harness may be used before recharging or replacement of the energy storage device 28 is required.

This is particularly important for construction work, where users may be required to wear the safety harness for an entire work shift.

Light-emitting diodes (LEDs) have numerous advantages such as: lower power demand, long lifetime, small size and physical robustness. All of these advantages make LEDs particularly suitable for the alerting device 24 of the safety harness system 10 shown in the figures.

In alternative embodiments, the alerting device 24 may include: two or more LEDs; an alternative light source; an audio alert e.g. a loudspeaker or siren; a vibration device; a wireless transmitter configured to transmit alerts to a phone or other computing device; or any combination of these components.

In some embodiments, the range and/or sensitivity of the sensing devices 16 are tuned for detection of a scaffold pole. In this way, the system is configured to be suitable for use on construction sites, where workers typically connect their safety hooks 14 to scaffold poles.

In alternative embodiments, the range and/or sensitivity of the sensing device 16 may be tuned for detection of a different object, such as a ladder rung or a lug of a structure or machine.

In some embodiments, the range and/or sensitivity of the sensing devices 16 is tuned by selection of appropriate resistors or other electrical components. In some embodiments, a potentiometer having a knob or other adjustable input may be provided for tuning the range and/or sensitivity of the sensing devices 16. The knob or other adjustable input may be provided on the central unit 30 or elsewhere on the harness 12. This may be useful, for example, when switching between connecting the safety hooks 14 to different objects (e.g. switching from a scaffold pole to a relatively narrower diameter ladder rung, or switching from a ferrous scaffold pole to a non-ferrous scaffold pole). In some arrangements, the knob or other adjustable input may be continuously adjustable. In other arrangements, the knob or other adjustable input may be discretely adjustable (e.g. a switch configured to alternate between two discrete states of the potentiometer).

In some embodiments, hard-wired logic circuitry may take signals from the sensing devices 16 as inputs and set the state of the alerting device 24 as an output, rather than using a processor 26 to implement the logic digitally, as illustrated in Figure 3.

Referring now to Figure 4, a safety hook 14 for use with the safety harness system 10 of Figure 1 is shown. In this embodiment, the sensing device 16 includes two sensors 55a, 55b, each having an associated detection region 57a, 57b, and the safety harness system 10 is configured to determine whether an object 54 (e.g. a scaffold pole) is entering or leaving the space defined by the hook 18 based on the order in which the object 54 (e.g. a scaffold pole) passes the detection regions 57a, 57b of the two sensors 55a, 55b. In other embodiments, more than two sensors 55a, 55b may be provided. In some embodiments, a single sensor having a plurality of detection regions is provided.

The two sensors 55a, 55b define two detection regions 57a, 57b, which are distributed along a path or travel Ni of an object 54 into or out of the space defined by the hook 18. In the embodiment illustrated in Figure 4, this is achieved via distributing the detection regions 57a, 57b (and sensors 55a, 55b) along a length of the clip 17 of the hook 14 (described further below). In alternative embodiments, the sensors 55a, 55b may be located at the same position along the longitudinal axis, but angled such that their respective detection regions 57a, 57b are distributed along the path Ni.

In alternative embodiments, the sensors 55a, 55b may be located within the body 15 of the hook 14, towards a tip end 61 of the body 15.

In the illustrated embodiment, the first sensor 55a has an associated first detection region 57a, and the second sensor 55b has an associated second detection region 57b. If the object 54 (e.g. scaffold pole) passes the first detection region 57a and then the second detection region 57b, the safety harness system 10 can determine that an object 54 (e.g. scaffold pole) is entering the space defined by the hook 18.

Conversely, if the object 54 (e.g. scaffold pole) passes the second detection region 57b followed by the first detection region 57a, the safety harness system 10 can determine that an object 54 (e.g. scaffold pole) is leaving the space defined by the hook 18.

In the embodiment illustrated in Figure 4, the safety hook 14 includes a body 15 having an opening 72 through which an object 54 can be introduced into and/or removed from the space defined by the hook 18. The hook 14 also includes a clip 17 coupled to the body 15. The clip 17 is configured to be moveable between a closed state (as shown in Figure 1) in which the clip 17 covers the opening 72, and an open state (as shown in Figure 4) in which an end of the clip 17 protrudes into the space defined by the hook 18 such that the opening 72 is not covered by the clip 17.

As previously mentioned, the sensing device 16 is provided in the clip 17 and/or the body 15. In the illustrated embodiment, the sensing device does not protrude into the space defined by the hook 18, which prevents it from being hit or damaged by an object 54 placed therein (e.g. a scaffold pole).

The clip 17 is biased towards the closed state. In this way, the clip is configured to cover the opening 72 unless the clip 17 is pushed to overcome the biasing force. This prevents an object 54 (e.g. a scaffold pole) within the space defined by the hook 18 from accidentally passing through the opening 72, which could result in an unsafe state for the harness wearer.

In the embodiment illustrated in Figure 4, the width of the opening 72 when the clip 17 is in the open state is approximately 2mm greater than the width of the object 54 intended for insertion through the opening (e.g. a scaffold pole). In other embodiments, the width of the opening 72 when the clip 17 is in the open state is in the range of lmm to 5mm greater than the width of the object 54 intended for insertion through the opening 72 (e.g. a scaffold pole). Such a clearance ensures that the object 54 passes close enough to the sensing device 16 in the clip 17 (and/or the body, in other embodiments), so that it can be detected by the sensing device 16. This reduces the chance of false negatives, which would be associated with a substantially larger clearance.

The clip 17 of Figure 4 includes a portion having a U-shaped cross-section defining a recess 75, as shown in Figure 5a. The U-shaped portion is formed of a surface 76 and a pair of side walls 74 extending from the surface 76 to define the recess 75. In the embodiment illustrated in Figures 4 and 5a, the sensing device 16 is provided in the recess 75 of the clip 17. In this way, as an object 54 (e.g. a scaffold pole) moves into or out of the space defined by the hook 18, via the opening 72, the object moves past the clip 17 (which is in the open state) and therefore past the sensing device 16 located in the recess 75 defined by the U-shaped portion of the clip 17. This ensures that the object 54 moves close enough to the sensing device 16 to be detected.

Referring now to Figure 5b, the sensing device 16 is positioned behind the surface 76 (i.e. within the recess 75). The clip 17 includes two apertures 78a, 78b provided in the surface 76 at locations corresponding to the position of the two sensors 55a, 55b. By providing these apertures 78a, 78b in the clip 17, the sensors 55a, 55b are able to detect the presence of an object 54 close to the clip 17, without detecting the surface 76 of the clip 17. In other words, these apertures 78a, 78b reduce the occurrence of false-positives.

The clip also includes a cutout portion 79a joining the apertures 78a and 78b, and a cutout portion 79b joining the aperture 78b with an end of the clip 17. When the clip 17 is made of metal, these cutout portions 79a, 79b prevent there being a complete circular conductive path around the apertures 78a, 78b. This has been found to improve the reliability of detection of an object 54 when the two sensors 55a, 55b are inductive sensors.

In the embodiment illustrated in Figures 4 to 5b, the sensors 55a, 55b are inductive sensors (also known as magnetic sensors). As will be appreciated by those skilled in the art, there are a wide range of off-the-shelf inductive sensors which may be suitable for this purpose. This reduces the cost and complexity of designing and manufacturing the system. Furthermore, since inductive sensors only detect conductive objects, this system prevents or reduces false alarms. For example, this system may prevent or reduce a user generating a false alarm by passing their hand along the outer edge of the clip. In a construction environment, the use of a sensor that only detects conductive objects encourages the user to attach a hook to a conductive safety object or structure, such as a scaffold pole or ladder rung.

In alternative embodiments, one or both of the sensors 55a, 55b may be a different kind of sensor (e.g. a resistive or capacitive sensors).

Referring now to Figures 6 and 7, a safety hook 114 suitable for use in the system described above in relation to Figure 2, is shown. The safety hook 114 is attached to a tubular object 154 (e.g. a scaffold pole).

In the embodiment illustrated in Figures 6 and 7, the sensing device 116 is a capacitive sensor 156. The capacitive sensor 156 comprises two conductive electrodes 158 in a substrate 160. In use, a voltage is supplied to the conductive electrodes 158 so that an electric field is provided therebetween. Intersection of the electric field by a conductive object (for example a scaffold pole) changes the capacitance of said electrodes 158.

Changes in the capacitance of the electrodes 158 can be evaluated by the processor to determine the presence or absence of an object. In this way, the presence of an object within the space 118 defined by the respective hook 114, such as a scaffold pole, ladder rung or other conductive support structure, can be detected.

In the embodiment illustrated in Figures 6 and 7, the substrate 160 is made of plastic. In alternative embodiments, the substrate 160 may be made of an alternative non-conductive material.

As shown in Figure 2, the space 118 defined by the hook 114 is defined by an inner perimeter 162 of the body 115 of the hook 114. In the illustrated embodiment, shown in Figure 6, the capacitive sensor 156 is located along a portion of the inner perimeter 162.

By locating the sensor 156 on the inner perimeter 162 of the body 115 of the hook 114, it is positioned where an object (e.g. a scaffold pole) is likely to rest, thereby facilitating the detection of the object.

This arrangement protects the conductive electrodes 158 from damage, at least to some degree. In addition, since an object that a hook 114 is attached to (e.g. a scaffold pole) is likely to make contact with at least some portion of the inner perimeter 162 of the body of the hook 114, locating the sensor 156 on this inner perimeter 162 allows the presence of said object to be easily detected.

Referring to Figure 8, a safety hook 114 according to an alternative embodiment is shown.

The safety hook 114 includes a receiving portion 164 (e.g. a groove running along the inner perimeter 162 of the body 115 of the hook 114). The receiving portion 164 is configured to receive the sensing device 116 therein. In alternative embodiments, the receiving portion 164 may be a different type of recess configured to receive at least a portion of the sensing device 116.

In this way, the shape of the body 115 of the safety hook 114 can be optimised for receiving the sensing device 116 (e.g. preventing the sensing device from protruding significantly from the inner perimeter 162 of the body 115 of the hook 114). This reduces the likelihood of damage to the sensing device (e.g. via catching on an object when the hook 114 is attached to it).

In the embodiment illustrated in Figure 8, the sensing device 116 located in the receiving portion 164 is a capacitive sensor 156 (as described above in relation to Figures 6 and 7). In alternative embodiments, the sensing device 116 located in the receiving portion 164 may be a different type of sensor 156, such as an inductive sensor 166 (as detailed below).

Referring to Figures 9 and 10, a safety hook 114 suitable for use in the system described above in relation to Figure 2, is shown. The safety hook 114 is attached to a tubular object 154 (e.g. a scaffold pole).

In the embodiment illustrated in Figures 9 and 10, the sensing device 116 is an inductive sensor 166.

In the embodiment illustrated in Figures 9 and 10, the safety hook 114 is made from a non-ferrous material. Since inductive sensors 166 are more sensitive to ferrous metals, having a non-ferrous hook 114 allows the sensor 166 to be tuned so that is capable of detecting a ferrous object within the space 118 defined by the hook 114 (e.g. a steel scaffold pole) without detecting the presence of the hook 114 itself.

In alternative embodiment, the safety hook 114 may be made from a ferrous metal.

The inductive sensor 166 includes a wire coil 168 attached to at least a portion of the inner perimeter 162 of the body 115 of the hook 114. The sensor 166 is configured to detect the presence of a metal object by supplying current to the coil 168, so that a magnetic field is induced. Intersection of the magnetic field by a metal object induces eddy currents and changes the impedance of the coil 168.

Changes in the impedance of the coil 168 can be evaluated by the processor to determine the presence or absence of an object (e.g. a scaffold pole) in the space 118 defined by the hook 114.

Since an object that a hook 114 is attached to (e.g. a scaffold pole) makes contact with the inner perimeter 162 of the body 115 of the hook 114, locating the sensor 166 on this inner perimeter 162 facilitates detection of the presence of said object.

In the illustrated embodiment, the safety hook 114 includes a locating region 170 configured for receiving a tubular object 154 such as a scaffold pole. The safety hook 114 also includes an opening 172 configured for insertion or removal of a tubular object 154 such as a scaffold pole. In the illustrated embodiment, the wire coil 168 is positioned on a portion of the inner perimeter 162 spaced away from the locating region 170 and opening 172 of the hook 114. Locating the sensor 166 away from where an object would rest reduces the likelihood of the wire coil 168 getting in the way, or being snagged by an object as the hook 114 is attached/detached.

According to one embodiment, the safety harness system 10 may include the system as described above in relation to Figures 1 and 3, and one or more safety hooks 14 as described above in relation to Figures 4, 5a and 5b. In another embodiment, the safety harness system 110 may include the system described above in relation to Figures 2 and 3, and one or more safety hooks 114 described above in relation to Figures 6 to 10.

In a further embodiment, the safety harness system 10, 110 may include one or more safety hooks 14, 114 having a combination of different sensing devices (e.g. the inductive sensors of Figures 4, 5a and 5b, as well as the capacitive sensor of Figures 6 and 7, and or the inductive sensor of Figures 9 and 10). This would offer redundancy, which could improve the reliability of the system.

In another embodiment, one or more sensing devices 16, 116 and/or other components described above may be provided as a kit of parts for attachment to an existing safety harness 12, 112.

In another embodiment, one or more safety hooks 14, 114 with sensing devices 16, 116 (as described above in relation to Figures 4 to 10) may be provided for attachment to an existing safety harness 12, 112.

Although the invention has been described in relation to one or more embodiments, it will be appreciated that various changes or modifications can be made without departing from the scope of the invention as defined in the appended claims. For example, it will be appreciated that: the number of safety hooks may vary; more than one sensing device may be provided on a hook, for increasing reliability of the detection of objects within the space defined by the hook; any suitable sensing device (e.g. capacitive, inductive, resistive or other type) may be used; different hooks may use different types of sensing device or the same type of sensing device; each safety hook may comprise more than one sensing device; and the processor and/or alerting device and/or energy storage device may be provided on the lanyard and/or any suitable location on the safety harness.

Claims

CLAIMS1. A safety harness system for use at an elevated work site, comprising: a harness configured to be worn; and a safety hook coupled to the harness, the safety hook comprising a sensing device configured to generate a signal indicative of the presence and/or absence of an object in a space defined by the hook.
2. A safety harness system according to claim 1, wherein the safety harness system is configured to determine the presence and/or absence of an object in the space defined by the hook based on the signal generated by the sensing device, and to trigger an alert unless an object is determined as being present in the space defined by the safety hook.
3. A safety harness system according to claim 1 or 2, wherein the safety harness system comprises two safety hooks, each comprising a sensing device configured to generate a signal indicative of the presence and/or absence of an object in a space defined by the respective hook.
4. A safety harness system according to claim 3, wherein the safety harness system is configured to determine the presence and/or absence of an object in the space defined by the respective hooks based on the signals generated by the respective sensing devices, and to trigger an alert unless an object is determined as being present in the space defined by at least one of the safety hooks.
5. A safety harness system according to any preceding claim, further comprising: an alerting device having an alerting state in which an alert is output from the alerting device, and an idle state in which no alert is output from the alerting device.
6. A safety harness system according to claim 5, further comprising a processor for determining the presence and/or absence of an object in the space defined by the or each hook based on the signal generated by the respective sensing device; wherein, the processor is configured to set the alerting device to the idle state when the processor determines that an object is present in the space defined by the or at least one hook, and to set the alerting device to the alerting state otherwise.
7. A safety harness system according to any preceding claim, wherein the or each sensing device comprises two or more detection regions, wherein the system is configured to determine whether an object (e.g. a scaffold pole) is entering or leaving the space defined by the hook based on the order in which the object (e.g. a scaffold pole) passes through the detection regions.
8. A safety harness system according to any preceding claim, wherein the or each safety hook comprises a body comprising an opening through which an object can be introduced into and/or removed from the space defined by the hook, the hook further comprising a clip coupled to the body, wherein the clip is configured to be moveable between a closed state in which the clip covers the opening, and an open state in which a free end of the clip protrudes into the space defined by the hook such that the opening is not covered by the clip, and wherein the sensing device is provided in the clip and/or the body
9. A safety harness system according to claim 8, wherein the clip comprises a portion having a U-shaped cross-section defining a recess, wherein the sensing device is provided in said recess of the clip.
10.A safety harness system according to claim 8 or 9, wherein the clip comprises one or more apertures through which the sensing device can detect the presence and/or absence of an object.
11.A safety harness system according to any preceding claim, wherein the sensing device comprises an inductive sensor.
12.A safety harness system according to any preceding claim, wherein the sensing device comprises a capacitive sensor.
13. A safety harness system according to any preceding claim, further comprising an energy storage device for providing power to the sensing device, and/or the or a processor and/or the or an alerting device.
14. A safety harness system according to any preceding claim, wherein the or each safety hook is coupled to the harness via a lanyard comprising a shock absorbing device.
15. A safety harness system according to any preceding claim, wherein the or each safety hook comprises a receiving portion (e.g. a groove or other recess) configured to receive the sensing device therein.
16. A safety harness system according to claim 5, wherein the alerting device comprises one or more of: a light source, e.g. at least one LED; an audio alerting device; a vibration device; or a wireless transmitter configured to transmit alerts to a phone or other computing device.
17. A kit of parts for providing a safety harness system for use at an elevated work site, the kit comprising at least one sensing device configured for attachment to a safety hook, wherein the or each sensing device is configured to generate a signal indicative of the presence and/or absence of an object in a respective predetermined area proximal the sensing device.
18. A kit of parts according to claim 17, further comprising: an alerting device having an alerting state in which an alert is output from the alerting device, and an idle state in which no alert is output from the alerting device. 15
19.A kit of parts according to claim 18, further comprising a processor for determining the presence and/or absence of an object in the or each predetermined area based on the signal generated by the respective sensing device; wherein, the processor is configured to set the alerting device to the idle state when the processer determines that an object is present in the respective predetermined area proximal the or at least one sensing device, and to set the alerting device to the alerting state otherwise.
20. A kit of parts according to any of claims 17 to 19, further comprising at least one safety hook, the or each safety hook comprising the respective sensing device.
21. A safety hook apparatus for a safety harness system for use at an elevated work site, the safety hook apparatus comprising at least one safety hook, the or each safety hook comprising a sensing device configured to generate a signal indicative of an object being present and/or absent in a space defined by the respective hook.
22.A safety hook apparatus according to claim 21, wherein the safety hook apparatus comprises two safety hooks coupled to a shock-absorbing lanyard configured for attachment to a harness, wherein each safety hook comprises a sensing device configured to generate a signal indicative of an object being present and/or absent in the space defined by the respective hook.
23.A safety hook apparatus according to claim 22, further comprising: an alerting device having an alerting state in which an alert is output from the alerting device, and an idle state in which no alert is output from the alerting device.
24.A safety hook apparatus according to claim 23, further comprising: a processor for determining the presence and/or absence of an object in the respective space defined by the or each hook based on the signal generated by the respective sensing device; wherein, the processor is configured to set the alerting device to the idle state when the processor determines that an object is present in the space defined by the or at least one hook, and to set the alerting device to the alerting state otherwise.