Patent Publication Number: US-9852598-B1

Title: Swing fall protection device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to a safety alarm, and more specifically to a safety alarm adapted for use with a self-retracting lanyard to provide an alert to an individual approaching an unsafe location. 
     2. Description of the Related Art 
     Fall protection devices, such as self-retracting lanyards, are well known and are commonly used in work environments where an individual may be susceptible from falling from an elevated location. One end of the self-retracting lanyard is typically connected to a harness worn by an individual, while the other end of the self-retracting lanyard is connected to an overhead support structure, such as a rail or beam. 
     A conventional self-retracting lanyard includes a main body and a retractable line coupled to the main body, with the retractable line having an exposed portion extending out of the main body. The main body and retractable line may be configured to allow the length of the exposed portion to increase or decrease during use of the self-retracting lanyard. In this regard, when the individual connected to the self-retracting lanyard moves about the elevated location, e.g., walking on the roof of a building, the length of the retractable line may continually increase or decrease as the individual moves relative to the main body. A spring biased spool may be located in the main body to allow for such selective lengthening and shortening of the exposed portion of the retractable line. In this regard, the spool may apply a force on the retractable line to keep the retractable line generally taut, while generally not inhibiting the individual&#39;s movement, e.g., walking, at the elevated location. 
     In the event the individual inadvertently falls from the elevated location, the self-retracting lanyard may break the fall to prevent serious injury to the individual. In particular, the self-retracting lanyard may include a braking device operatively coupled to the retractable line, with the braking device being actuatable in response to the individual&#39;s fall to restrict further extension of the retractable line from the main body, which in turn, stops the fall of the individual. The actuation of the braking device may be triggered via the individual&#39;s inertia during the fall. 
     Although the self-retracting lanyard may provide protection against severe injury in the event of an inadvertent fall, there remains a desire to prevent such inadvertent fall altogether. Along these lines, the individual may suffer minor physical and/or mental injuries as a result of such fall. For instance, the individual may lose confidence when operating at elevated locations, which may impact the ability of the individual to perform his job. Furthermore, the environment in which the individual is working may be associated with zones or regions that are particularly more prone to injury, such as a location associated with a dangerously hot exhaust. It may be desirable to provide a warning to an individual as the individual approaches such dangerous zone. 
     Accordingly, there is a need in the art for a device, usable with a self-retracting lanyard which provides a warning to an individual approaching a potentially dangerous location. Various aspects of the present disclosure address this particular need, as will be discussed in more detail below. 
     BRIEF SUMMARY 
     In accordance with one embodiment of the present disclosure, there is provided a method and apparatus adapted for providing an alert to an individual attached to a self-retracting lanyard when the individual is approaching an unsafe position. In particular, various aspects of the present disclosure relate to measuring an angle of the self-retracting lanyard, relative to a vertical axis, and generating an alert signal when the angle exceeds a preset magnitude. 
     According to one embodiment, there is provided an alarm device adapted for use with a self-retracting lanyard having a main body and a retractable line coupled to the main body. The alarm device includes a housing adapted to be engageable with the retractable line. The housing defines a detection axis, with the housing being adapted to allow at least a portion of the retractable line to be parallel to the detection axis when the housing is engaged with the retractable line. An inclinometer is coupled to the housing and is adapted to detect a magnitude of an angle between the detection axis and a vertical axis, and generate an electrical signal when the magnitude exceeds a preset threshold. An alarm element is in communication with the inclinometer to receive the electrical signal generated by the inclinometer. The alarm element is adapted to generate an alert signal in response to receipt of the electrical signal. 
     The housing may be a clam-shell housing including two bodies pivotally coupled to each other. The housing may be adapted to be circumferentially engageable with the retractable line. The housing may include a body and a central channel about which the housing body is located, the housing being adapted to allow the retractable line to reside within the central channel when the housing is engaged with the retractable line. The housing may also be configured to allow at least a portion of the retractable line to extend along detection axis when the housing is engaged with the retractable line. 
     The preset threshold may be between twenty degrees and forty degrees. The preset threshold may be thirty degrees. 
     A resilient bushing may be coupled to the housing and disposed about the detection axis. 
     The alarm element may be adapted to generate a visual signal. The alarm element may include a light strip extending over an outer surface of the housing. The light strip may substantially circumnavigate the detection axis. The alarm element may be adapted to generate an audible signal. 
     A method of providing an alert to a user coupled to a self-retracting lanyard. The method includes: detecting a magnitude of an angle between a retractable line of the self-retracting lanyard and a vertical axis using an inclinometer, the inclinometer being located within a housing coupled to the retractable line; and generating an alert signal using an alert element when the magnitude exceeds a preset threshold. 
     The generating step may include generating an alert signal when the magnitude is above twenty degrees. The generating step may include generating an alert signal when the magnitude is equal to thirty degrees. 
     The method may further comprise the step of imparting an engagement force on the retractable line. The imparting step may include imparting a circumferential engagement force on the retractable line. 
     The present disclosure will be best understood by reference to the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which: 
         FIG. 1  is a front view of an alarm device coupled to a retractable line of a self-retracting lanyard, the retractable line being in a generally vertical configuration; 
         FIG. 2  is a front view of the alarm device, with the retractable line being separated from a vertical axis by an angle associated with an unsafe condition; 
         FIG. 3  is a front view of the alarm device in an open configuration; 
         FIG. 4  is an upper perspective view of the alarm device in a closed configuration to secure the alarm device to the retractable line; 
         FIG. 5  is an upper perspective exploded view of a bushing which forms part of the alarm device to dissipate impact forces imparted on the alarm device; 
         FIG. 6  is a front sectional view of the bushing depicted in  FIG. 5 ; and 
         FIG. 7  is a schematic diagram of electrical components of the alarm device. 
     
    
    
     Common reference numerals are used throughout the drawings and the detailed description to indicate the same elements. 
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of certain embodiments of an alarm device for a self-retracting lanyard and is not intended to represent the only forms that may be developed or utilized. The description sets forth the various structure and/or functions in connection with the illustrated embodiments, but it is to be understood, however, that the same or equivalent structure and/or functions may be accomplished by different embodiments that are also intended to be encompassed within the scope of the present disclosure. It is further understood that the use of relational terms such as first and second, and the like are used solely to distinguish one entity from another without necessarily requiring or implying any actual such relationship or order between such entities. 
     Various aspects of the present disclosure pertain to an alarm device specifically configured and adapted for use with a self-retracting lanyard. Along these lines, it is understood that self-retracting lanyards may be connected to a harness worn by an individual working or otherwise located in a potentially dangerous environment, such as an elevated location associated with a falling hazard. The alarm device may be connected to a retractable line of the self-retracting lanyard to provide an alert to the individual when the individual approaches a particularly unsafe location. Thus, when the individual perceives the alarm, the user may return to a safe position. Accordingly, the alarm device may provide an additional level of protecting to the individual. 
     Referring now to the drawings,  FIG. 1  depicts an exemplary embodiment of an alarm device  10  coupled to a self-retracting lanyard  12 . As used herein, the term “self-retracting lanyard” refers to a fall protection device that is attached to a safety harness  13  worn by an individual when the individual is located in an environment, which would cause injury to the individual should the individual inadvertently fall from such environment. For instance, the self-retracting lanyard  12  may be used when located on building scaffolding, on construction sites, on the roof or elevated floor of a building, on top of large machinery, on the outside of large airplanes, or other elevated environments. The terms “retractable lanyard” or “self-retracting lifeline” may also be used to refer to the self-retracting lanyard  12 . 
     According to one embodiment, the self-retracting lanyard  12  includes a main body  14  and a retractable line  16  or lanyard extending from the main body  14 . The main body  14  is connected to an overhead support rail  18 . In some instances, the main body  14  may be translatable along at least a portion of the support rail  18 , while in other instances, the main body  14  is generally fixed relative to the support rail  18  such that the main body  14  cannot translate relative thereto. In the embodiment depicted in  FIGS. 1 and 2 , the main body  14  can pivot relative to the upper support rail  18 , but cannot translate along the support rail  18 . 
     The retractable line  16  may be transitioned relative to the main body  14  between a retracted configuration and an extended configuration, wherein the amount of the line  16  extending out of the main body  14  increases as the retractable line  16  transitions from the retracted configuration to the extended configuration. In this regard, the main body  14  may include a spring-biased spool about which the retractable line  16  is wound. Furthermore, the self-retracting lanyard  12  may be specifically configured to utilize inertia to activate a braking mechanism to protect the individual from the fall. An exemplary self-retracting lanyard  12  is the DEFY™ Self-Retracting Lanyard sold by Rigid Lifelines, although it is expressly contemplated that other self-retracting lanyards known in the art may be used with the alarm device  10  described herein. 
       FIGS. 1 and 2  depict a user connected to the self-retracting lanyard  12  and located on a platform  20 .  FIGS. 1 and 2  also depict a safe zone  22  and an unsafe zone  24  on the platform  20 . An objective of the alarm device  10  is for the individual to remain on the platform  20  and in the safe zone  22 , as shown in  FIG. 1 . To that end, the alarm device  10  is adapted to provide an alert to the individual should the individual exit the safe zone  22  and enter the unsafe zone  24 , as shown in  FIG. 2 . A comparison of  FIGS. 1 and 2  illustrates that the angle of the retractable line  16  relative to a vertical axis  26  increases as the individual transitions from the safe zone  22  to the unsafe zone  24 . The importance of this change in angle will be described in more detail below. 
     According to one embodiment, the alarm device  10  includes a housing  28  adapted to be engageable with the retractable line  16 . In the exemplary embodiment, the housing  28  is adapted to be engaged with, or coupled to, the retractable line  16 , such that the retractable line  16  passes through the housing  28 . Referring now specifically to  FIGS. 3 and 4 , to effectuate such engagement between the housing  28  and the retractable line  16 , the exemplary housing  28  is a clam-shell housing having two bodies  30 ,  32  pivotally coupled to each other. The bodies  30 ,  32  are configured to transition between an open configuration, as shown in  FIG. 3 , and a closed configuration, as shown in  FIG. 4  to secure the housing  16  to the retractable line  16 . The bodies  30 ,  32  preferably pivot between the open and closed configurations, with the bodies  30 ,  32  being coupled via a hinge  34  defining a hinge axis  36 . Each body  30 ,  32  includes a respective edge  38 ,  40  opposite the hinge  34 . As the housing  28  transitions from the open configuration toward the closed configuration, the edges  38 ,  40  move toward each other to allow complimentary latches  42  or other closing mechanisms to engage with each other to maintain the housing  28  in the closed configuration. To transition the housing  28  from the closed configuration to the open configuration, the latches  42  are disengaged, and the bodies  30 ,  32  are pivoted about the hinge axis  36  in an opposite direction, which results in the edges  38 ,  40  moving away from each other, until the bodies  30 ,  32  reach the configuration shown in  FIG. 3 . The clam-shell design of the housing  28  allows the alarm device  10  to be selectively placed on the retractable line  16 . In this regard, the housing  28  may be easily retro-fitted on existing self-retracing lanyards  12 . 
     The housing  28  includes a channel  44  extending axially therethrough, with the channel  44  being configured to receive the retractable line  16 . In the exemplary embodiment, the channel  44  is collectively defined by both housing bodies  30 ,  32 . When the housing  28  is in the closed configuration and the retractable line  16  passes through the channel  44 , the housing  28  is circumferentially engaged to the retractable line  16 . 
     The housing bodies  30 ,  32  may be formed from a polymer material or other materials known by those skilled in the art. Furthermore, the housing  28  may be formed of a weather resistant material, or have a weather resistant coating or covering applied thereto to allow the alarm device  10  to be used outside and endure the elements, e.g., rain, snow, ice, etc. 
     Disposed within the channel  44  are a pair of bushings  46 , which protect the housing bodies  30 ,  23  as the retractable line  16  is extended and retracted. In particular, the bushings  46  may protect one end of the housing  28  from inadvertent contact with the main body  14  of the self-retracting lanyard  12 , and the other end of the housing  28  from inadvertent contact with hardware associated with the safety harness  13  worn by the individual. In this regard, the bushings  46  may be formed of a resilient, shock absorbing material, such as rubber. 
     According to one embodiment, the bushing  46  is segmented into two bushing bodies  46   a ,  46   b  to facilitate placement of the bushing  46  on the retractable line  16 . In this regard, both ends of the retractable line  16  may be secured to hardware which may make it difficult to pass an end of the retractable line  16  through the bushing  46  for purposes of connecting the retractable line  16  to the bushing  46 . Therefore, the segmented configuration of the bushing  46  allows the bushing  46  to be more easily attached to the retractable line  16 . To that end, each bushing body  46   a ,  46   b  may include a pair of apertures  47  which are aligned with a pair of corresponding apertures  47  formed on the other bushing body  46   a ,  46   b . When the apertures  47  are aligned, the apertures  47  are adapted to receive a pair of screws or other fasteners for securing the bushing bodies  46   a ,  46   b  together. The bushing  46  may include an aperture  47  which may accommodate a set screw or other securing device for effectuating engagement between the bushing bodies  46   a ,  46   b . In this regard, one of the bushing bodies  46   a ,  46   b  may include internal threads to engage with the fastener/screw. When the bushing bodies  46   a ,  46   b  are connected to each other about the retractable line  16 , the bushing bodies  46   a ,  46   b  may impart a circumferential force on the retractable line  16  to secure the bushing  46  to the retractable line  16 . 
     As shown in  FIGS. 3, 5, and 6 , one embodiment of the bushing  46  includes an outer surface defining a stepped configuration, which is complimentary to a stepped configuration of the channel  44  to facilitate engagement between the bushing  46  and the housing  28 . In particular, one end portion of the bushing  46  defines a first outer diameter OD 1 , while a second end portion of the bushing  46  defines a second outer diameter OD 2  less than the first outer diameter OD 1 . The first and second end portions are separated by a shoulder  49  which extends between the first and second outer diameters OD 1 , OD 2 . The bushing  46  also includes an inner diameter ID that is sized to allow the retractable line  16  to extend therethrough, while at the same time creating friction, i.e., an engagement force, between the bushing  46  and the retractable line  16 . In this regard, each bushing  46  is sized to be compatible with a retractable line  16  having a specific diameter. Thus, the bushings  46  may be interchanged with different bushings  46  having inner diameters compatible with a specific sized retractable line  16 . In this regard, the outer configuration of the bushings  46  may remain constant to allow for universal adaptation with a common housing  28 . 
     The housing  28  defines a detection axis  48 , with the housing  28  being adapted to allow at least a portion of the retractable line  16  to be parallel to the detection axis  48  when the housing  28  is engaged with the retractable line  16 . Preferably, and as shown in  FIG. 4 , a portion of the retractable line  16  extends along the detection axis  48  when the housing  28  is engaged with the retractable line  16 , although the scope of the present disclosure is not limited thereto. In the exemplary embodiment, the detection axis  48  is defined by the channel  44  which receives the retractable line  16 , with the channel  44  being disposed about the detection axis  48  when the bodies  30 ,  32  are in the closed configuration. 
     Reference is now made to  FIG. 7 , which is an exemplary schematic depiction The alarm device  10  includes several electrical components, including a processor  50 , an inclinometer  52 , a communication port  54 , a power element  56 , a speaker  58 , a memory module  60 , a first alarm light  62 , a second alarm light  64 , and a vibrating alarm element  66 . 
     The processor  50  is preferably located within the housing  28  and is adapted to provide the computing ability to interface the various electrical components with each other, and also implement the functionality described herein. 
     The inclinometer  52  is in electrical communication with the processor  50  and is preferably located within the housing  28 . The inclinometer  52  is configured to measure a magnitude of an angle, Θ, between the detection axis  48  and a vertical axis  26 . In this regard, the inclinometer  52  is used to measure an angle of tilt of the retractable line  16 . The inclinometer  52  is further configured to generate an electrical signal when the magnitude of the angle Θ (e.g., tilt) exceeds a preset threshold. 
     According to one embodiment, the preset threshold may be between twenty degrees and forty degrees, and more specifically may be thirty degrees. It is contemplated that any preset threshold may be associated with a tolerance, such that the inclinometer  52  may determine that the preset threshold is met when the measurement is within a couple degrees of the preset threshold. The tolerance may be an industry accepted tolerance, although in one particular embodiment, the tolerance may be as large as +/−5 degrees. 
     It is contemplated that the preset threshold may be set at a manufacturing facility, and thus, the device  10  may be configured such that it does not readily allow an individual to modify the preset threshold. Restricting the ability to readily change the preset threshold may provide additional safety and ensure that the alarm device  10  is operating as an employer intends. However, it is also contemplated that other embodiments of the alarm device  10  may be configured to allow for variation of the preset threshold by the user. User adjustment may be effectuated through adjustment buttons (not shown) integrated into the alarm device  10 , or through another user interface known by those skilled in the art. 
     As noted above, the alarm device  10  includes speaker  58 , first alarm light  62 , second alarm light  64 , and vibrating alarm element  66  each of which may be generally referred to individually or collectively as an “alarm element.” In this regard, the speaker  58  is adapted to provide an audible alert to the user or nearby co-worker, while the first and second alarm lights  62 ,  64  are adapted to provide visual alerts to the user or nearby co-worker, and the vibrating alarm element  66  is adapted to provide a vibratory or touch sensitive alarm to the user. The alerts provided by the speaker  58 , first alarm light  62 , second alarm light  64 , and vibrating alarm element  66  may continue for as long as angle detected by the inclinometer  52  meets or exceeds the preset threshold. Alternatively, the alerts may be generated only once for each time the inclinometer  52  detects an angle that meets or exceeds the preset threshold, with the inclinometer  52  requiring a “reset” by detecting an angle below the preset threshold before generating another actuating signal. 
     Each of the speaker  58 , first alarm light  62 , second alarm light  64 , and vibrating alarm element  66  are in operative communication with the inclinometer  52  to receive the electrical signal generated by the inclinometer  52  when the inclinometer  52  detects the magnitude of the angle as satisfying the preset threshold. The speaker  58 , first alarm light  62 , second alarm light  64 , and vibrating alarm element  66  are adapted to generate respective alert signals in response to receipt of the electrical signal. 
     As shown in the schematic diagram the speaker  58 , first alarm light  62 , second alarm light  64 , and vibrating alarm element  66  are in electrical communication with the processor  50 , and as such, the speaker  58 , first alarm light  62 , second alarm light  64  and vibrating alarm element  66  may “receive” the electrical signal generated by the inclinometer  52  via the processor  50 . In other words, the electrical signal may be generated by the inclinometer  52  and transmitted to the processor  50 , which in turn communicates an actuation signal to the speaker  58 , first alarm light  62 , second alarm light  64 , and vibrating alarm element  66 . Alternatively, the inclinometer  52  may communicate directly with the speaker  58 , first alarm light  62 , second alarm light  64 , and vibrating alarm element  66 . 
     The speaker  58  may be coupled to the housing  28  and is adapted to generate an audible alert when the preset threshold is met. The audible alert may include a series of beeps, a long continuous alert, or other audible alert signals known in the art. The audible alert may be heard by the individual wearing the harness  13  and/or by a nearby co-worker who may be able to communicate with the individual to return to the safe zone  22 . 
     According to one embodiment, the first alarm light  62  and second alarm light  64  are each comprised of an arcuate light strip extending over an external surface of the housing  28 . The first and second alarm lights  62 ,  64  may be viewed by the individual in the harness  13  and/or by a co-worker who can provide assistance. The first and second alarm lights  62 ,  64  extend substantially 360 degrees about the detection axis  48 . It is understood that the alarm lights  62 ,  64  may not extend completely 360 degrees in order to account for the clam-shell design of the housing  28 . In this regard, the lights  62 ,  64  may be disrupted at the interface of the housing bodies  30 ,  32 . 
     The alarm lights  62 ,  64  may generate a wide variety of visual alarms known in the art. For instance, the alarm lights  62 ,  64  may generate different colors, different blinking patterns, constant light emission, etc. 
     Since the alarm device  10  may be used in loud environments, it is understood that the audible alert provide by the speaker  58  may not be heard. Furthermore, in many instances, the first and second alarm lights  62 ,  64  may be located behind the individual in the harness  13 , and thus, the visual alarms may not be readily perceived. Therefore, the vibrating alarm element  66  is intended to provide an alert which may be more readily perceived by the individual. In this regard, when the inclinometer  52  generates the electrical signal associated with the unsafe condition, the vibrating element  66  may begin vibrating, with such vibrations being communicated along the retractable line  16  such that the vibrations are sensed by the individual. 
     The alarm device  10  may also include a velocimeter  55  to measure the velocity of the alarm device  10  and location monitor  57  to measure the location of the alarm device  10  as it moves. The measured velocity and location data may be stored in the memory module  60  for subsequent review. Such measured velocity and location data may be desirable to review in the event the individual inadvertently falls from the elevated location, so as to allow for analysis of data associated with the fall. 
     In addition to storing data generated by the velocimeter  55  and location monitor  57 , the memory module  60  may also be configured to store data generated by the inclinometer  52 . Such data may be retrieved through the communication port  54 , which may be a physical port, such as a USB-port, to allow the data on the memory module  60  to be downloaded to a remote electronic device. It is also contemplated that the communication ort  54  may be capable of wireless communication, such as WiFi or Bluetooth™ communication, thereby allowing wireless downloading of the data from the memory module  60 . 
     The electrical components receive power from a power module  56 , i.e., battery, located in the housing  28 . The distribution of power from the battery  56  may be governed by the processor  50 . 
     With the basic structural features of the alarm device  10  being described above, an exemplary use of the alarm device  10  is provided below. 
     An alarm device  10  is connected to the retractable line  16  of the self-retracting lanyard  12 . In one embodiment, the alarm device  10  is adapted to frictionally engage the retractable line  16 , and apply a circumferential force thereon to substantially restrict movement of the alarm device  10  along the retractable line  16 . 
     In one embodiment, the alarm device  10  may be transitional between ON and OFF modes, and thus, the user may transition the device  10  from the OFF mode to the ON mode. Such transition may occur automatically upon detection of movement of the alarm device  10 , e.g., detection of changes of inclination by the inclinometer, or alternatively, the individual may actuate a button or other actuator to cause such transition. 
     With the alarm device  10  ON, the individual performs his work at the elevated location. As the individual moves along the platform  20 , the inclinometer  52  detects the magnitude of an angle between a retractable line  16  of the self-retracting lanyard  12  and the vertical axis. The inclinometer generates a signal when the detected magnitude exceeds a preset threshold. That signal is then communicated to an alert element, such as the speaker  58 , first light alarm  62 , second light alarm  64  and/or vibrating alarm element  66 . The alarm element then emits a signal to provide an alert to the user that the user is in an unsafe location, and to return to a safer zone or region. 
     Thus, when the individual attached to the self-retracting lanyard  12  perceives the emitted signal, whether audibly, visually or through touch-sensation, or a nearby co-worker hears or views the signal, the individual may be made aware of the potentially dangerous condition, and can return to safety, which mitigates likelihood of harm from fall or other dangerous conditions. Along these lines, although it is contemplated that the unsafe zone or region may be associated with an increased likelihood of fall, it may be associated with other hazards, such as temperature hazards, chemical hazards, etc. 
     The particulars shown herein are by way of example only for purposes of illustrative discussion, and are not presented in the cause of providing what is believed to be most useful and readily understood description of the principles and conceptual aspects of the various embodiments of the present disclosure. In this regard, no attempt is made to show any more detail than is necessary for a fundamental understanding of the different features of the various embodiments, the description taken with the drawings making apparent to those skilled in the art how these may be implemented in practice.