Abstract:
Harnesses for use by a person at height are disclosed. A harness includes a plurality of flexible harness elements, each of which, when in use, encircles part of a user&#39;s body. Some or all of the harness elements include a connection piece. A bridge extends between a respective connection piece of two or more harness elements, the bridge extending across a part of a user&#39;s body. A connection assembly is connected to the bridge to convey at least part of a user&#39;s weight from the harness to a support element. The connection assembly has a coupling element that at least partially surrounds and that can move along the bridge and is capable of loading the bridge at spaced-apart locations. This provides comfort without the need to include any elongate, rigidly-attached component, the presence of which could reduce the flexibility of the harness.

Description:
BACKGROUND TO THE INVENTION 
       [0001]    Field of the Invention 
         [0002]    This invention relates to harnesses. Specifically, it relates to harnesses that are intended for use by a person at height, such as a climber or a person working at height. 
         [0003]    Users who work at height may spend many hours at a time in a harness to perform work tasks on structures, buildings and trees. A typical user will wear an industrial climbing harness and be attached to a climbing system to enable them to position themselves in a location to perform the work tasks required. The harness must not only provide comfortable and safe support for the user, it must also allow the user freedom of movement to climb and maneuver themselves within their working environment. 
         [0004]    A commercial user may spend many hours at a time in a harness when working in this way. Therefore, any potential source of discomfort in the harness is likely to lead to actual discomfort over time, which may ultimately lead to a reduction in the time a user can spend working in the harness. It is therefore in both the interest of productivity and of the welfare of the user to ensure that potential sources of discomfort in a work harness are, so far as is possible, minimized. 
         [0005]    In general, any part of the harness which is likely to cause a localized increase in the pressure applied to a user&#39;s body is a potential source of discomfort, and it is recognized that steps should be taken in designing a harness to avoid any potential source of raised pressure. 
         [0006]    Summary of the Prior Art 
         [0007]    One approach to solving this problem is to provide a rigid or semi-rigid platform that acts as a seat to provide the primary support for a user&#39;s weight. For example, this arrangement can be seen in US-A-2009/314578. Comfort may potentially be further improved by providing a bosun&#39;s chair arrangement that provides a broad and potentially cushioned sitting platform. However, the presence of a rigid structure in both of these arrangements can restrict a user&#39;s freedom of movement, and can be unwieldy when working in a partially-obstructed space, such as amongst branches of a tree canopy or maneuvering through a manhole. Therefore, many users still prefer a fabric harness made of flexible material including ropes and webbing. 
         [0008]    To place the invention in context, a known harness to which it might be applied is shown in  FIGS. 1 and 2 . The main components of such a harness include a waist belt  10 , leg loops  12 , a bridge  14 , an attachment eye  16 , top Ds  18  and forward Ds  20 . The bridge  14 , which in this example is a length of fabric rope, extends between eyes on the respective forward Ds and the attachment eye  16  surrounds and can slide along the bridge  14 . 
         [0009]    For use, a user is secured within the harness with the waist belt  10  around their waist, and with each leg loop  12  surrounding a respective one of the user&#39;s thighs. In this position, each forward D  20  lies to the outside of the user&#39;s leg  26 . A climbing rope  28  is connected to the attachment eye  16 , typically by way of a carabiner, to carry the user&#39;s weight through the leg loops  12 . The attachment eye  16  can float along and pivots upon the bridge  14  when the user moves from side to side. This gives the user unrestricted movement and means the harness adapts to the users shape when they twist, pivot and move, which is considered by users to be a particular advantage of this type of harness. 
         [0010]    A problem arises with this arrangement because the bridge  14  extends in two lengths from the attachment eye  16 , so that the force applied to each of the forward Ds  20  has an inward component F i  that is directed towards the other of the forward Ds  20  as well as a force F o  that acts away from the user. This is shown diagrammatically in  FIG. 3A . Such harnesses are wrapped around a user, with a U-shaped rear part applying the load to the user. When loaded from the ventral attachment point, the harness compresses the width of the loaded U shape, reducing the loaded contact area and compressing the body of the user. This inward component can result in localized pressure, and possible discomfort after long-term use. Therefore, known harnesses put stress and pressure on the user due to constricting the user&#39;s hips, legs and buttock area when under load due to the single attachment eye point which is of limited width. One attempted solution is to add a seat to the rear of the harness, as illustrated in  FIG. 3B , however there is still discomfort because of the rigid nature of the seat. Moreover, harness seats are cumbersome and can restrict the movement and rope positioning ability of the user due to the position behind the legs and rigid nature of the seat. 
         [0011]    An improvement to this type of harness is disclosed in EP-A-2 781 235. This proposes making a rigid interconnection between what is called here the forward Ds. However, this requires an extended, rigid component to be connected to the harness, which can restrict a user&#39;s freedom of movement and which removes some of the flexibility that is appreciated in this type of harness. 
       SUMMARY OF THE INVENTION 
       [0012]    An aim of this invention is to avoid or reduce this potential disadvantage without compromising the flexibility of this type of harness. 
         [0013]    To this end, from a first aspect, this invention provides a harness for use by a person at height comprising:
       a plurality of flexible harness elements, each of which, when in use, encircles part of a user&#39;s body, wherein some or all of the harness elements include a connection piece;   a bridge extending between a respective connection piece of two or more harness elements, the bridge extending across a part of a user&#39;s body;   connection means connected to the bridge to convey at least part of a user&#39;s weight from the harness to a support element; wherein:   the connection means has coupling means that at least partially surrounds and that can move along the bridge and is capable of loading the bridge at spaced-apart locations.       
 
         [0018]    The aim of improving comfort is thereby achieved, without the need to provide any elongate, rigidly-attached component, and thereby maintain the flexibility of the harness. 
         [0019]    The bridge is typically an elongate flexible component, intended to be loaded under tension. It may take a wide variety of forms, being, for example, formed from rope (wire or textile), webbing, cable, or otherwise. 
         [0020]    The coupling means may be capable of distributing load along a length of the bridge that is a substantial proportion of the dimension of a user&#39;s body that is spanned by the bridge: that is to say, it may exceed 10%, 20%, 25%, 50% or 100% of that dimension. For example, where the bridge extends across a user&#39;s trunk or hips, the coupling means may spread its load over a distance in the range of 100 mm to 500 mm or more. 
         [0021]    For example, the coupling means may have a tubular body through which the bridge extends. In such a case, the load is spaced apart on the bridge by the length of the tubular body. Alternatively, the coupling means may have a plurality of spaced guides through which the bridge passes. In such a case, the load is spaced apart on the bridge by the distance between the guides. The bridge makes sliding or rolling contact with the body while the harness is in use, which can cause parts of the body to wear over time. Therefore, it may be advantageous for those parts of the body with which the bridge makes contact may be formed as separate components that can be removed and replaced independently of other parts of the harness. Advantageously, each of these components may be configured such that it can be connected to the coupling means in a plurality of orientations such that if excessive wear occurs at one part of the component, it can be removed from the body and re-installed in a different orientation, whereby an unworn part of the component makes contact with the bridge. 
         [0022]    In some embodiments of the invention, the coupling means is capable of loading the bridge at spaced-apart locations when in a first configuration, and in a second configuration, loads the bridge at closely-spaced locations. This allows a user to choose between maximizing comfort and maximizing freedom of movement. For example, such embodiments (or others) may have loading components, such as loading arms, each of which carries a loading element, the distance between the loading elements determining the extent to which the load is spaced along the bridge. These loading components may be mutually movable (e.g., by pivoting, sliding, screwing, or moving telescopically) to adjust the spacing between the loading elements. 
         [0023]    In these embodiments, due to the large loads apparent on the spaced-apart locations, a load-limiting means may be provided to enable the device to break non-catastrophically in the event that the load exceeds a safe threshold. The load-limiting means may include a breaker bolt or breaker link that will fail at a predetermined force to return to the second, closely-spaced and thus stronger configuration to enable a non-catastrophic collapse of the device. This may give the user the ability to carry on using the device in the closed position whilst being rescued or performing self-rescue. Thus, when in the first configuration, a load on the bridge exceeds a threshold, the loading components are caused to move towards their second configuration. 
         [0024]    The connection means typically includes linking means that can be used to link the connection means to an external component, such as a carabiner or a sling. Most advantageously, the connection means permits pivotal movement between the connection means and the external component. Such pivotal movement is preferably permitted about more than one axis. Such axes are preferably normal to and parallel to the bridge in the region of the connecting means. 
         [0025]    Preferably, contact between the bridge and the connection means is made through components configured to minimize friction and/or abrasion with the bridge. For example, contact between the bridge and the connection means may be made through rolling elements or through smooth and/or curved surfaces. 
         [0026]    The support element is typically a climbing line. 
         [0027]    Embodiments of the invention will now be described in detail, by way of example, and with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]      FIGS. 1 and 2  show a conventional harness to which embodiments of the present invention might be applied, and have already been discussed; 
           [0029]      FIGS. 3A and 3B  are diagrams that show forces acting within the harness of  FIGS. 1 and 2 ; 
           [0030]      FIGS. 4 and 5  are side and end views of a load-spreading assembly being a component of an embodiment of the invention; 
           [0031]      FIG. 6  is a cross-sectional view of the load-spreading assembly of  FIGS. 4 and 5 ; 
           [0032]      FIG. 7  is a diagonal view of the load-spreading assembly of  FIGS. 4 and 5  showing it in place on a rope; 
           [0033]      FIG. 8  is a view of the load-spreading assembly of  FIGS. 4 to 6  in an alternative configuration; 
           [0034]      FIG. 9  is a diagram equivalent to  FIG. 3  that shows forces acting within the harness that is an embodiment of the invention; 
           [0035]      FIGS. 10, 11 and 12  are diagonal views of a load-spreading assembly being a component of an alternative embodiment of the invention in closed and open configurations,  FIGS. 11 and 12  showing opposite sides of the assembly; 
           [0036]      FIGS. 13 and 14  show a further embodiment of the invention in a first configuration; 
           [0037]      FIG. 15  shows the embodiment of  FIGS. 13 and 14  in a second configuration; 
           [0038]      FIGS. 16 and 17  show a further embodiment of the invention in a first configuration; 
           [0039]      FIGS. 18 and 19  show the embodiment of  FIGS. 14 and 15  in a second configuration; 
           [0040]      FIGS. 20 and 21  show a variation of the embodiment of  FIGS. 4 to 8 ; 
           [0041]      FIG. 22  is an exploded view of the embodiment of  FIGS. 20 and 21 ; and 
           [0042]      FIGS. 23 and 24  show a variation that can be applied to embodiments of this invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0043]    With reference to the drawings, an embodiment of the invention is a modification of the harness of  FIGS. 1 and 2  and should be assumed to include all of the components of that harness. This embodiment comprises all of the components of that harness, with the exception of the attachment eye  16 , which is replaced by a load-spreading assembly, as will now be described. 
         [0044]    The load-spreading assembly comprises a tubular body  30  which, in this embodiment, is formed from light alloy by forging, machining and/or casting. The body has a central, cylindrical passage  32  that extends lengthways, parallel to a long axis A, through it. End portions  34  of the cylindrical passage  32  are radiused, so as to present no sharp edges and reduce frictional forces in movement at the ends of the passage  32 . The length of the passage in this embodiment is approximately 120 mm, but this may be varied to accommodate users of different sizes and a range of applications and working environments. 
         [0045]    Centrally along the length of the body there is an attachment point. The attachment point comprises a swivel connector  40  and two flange portions  42  of the body  30 . 
         [0046]    The flange portions  42  have facing surfaces that are spaced apart and parallel to one another to opposite sides of the axis A. Centrally, an aperture is formed through each flange portion  42 , these apertures being coaxial and transverse to the axis A. In the region of the flange portions  42 , the passage  32  is open in a direction radially of the axis; however, this is for convenience of manufacture, and is not an essential feature of embodiments of this invention. 
         [0047]    The swivel connector  40  comprises a boss  46  and an eye  50 , these being interconnected for free mutual rotation about a swivel axis B. The boss  46  has spaced parallel surfaces, and an aperture that extends through the boss between them (not shown). A pivot bolt  52  passes through the apertures in the flange portions  42  and the boss  46  and is retained by a nut  54  recessed into one of the flange portions  42 . This allows the boss  46 , and therefore the entire swivel connector  40 , to pivot about a pivot axis C that is coaxial with the pivot bolt  52 , as shown in  FIG. 8 . 
         [0048]    In use, the bridge  14  of the harness passes through the cylindrical passage  32 . A climbing rope is connected to the swivel connector, typically through a carabiner that passes through the eye  50 . As with the conventional harness, the position of the climbing rope can pivot and float with respect to the bridge by: 
         [0049]    the tubular body  30  sliding along the bridge  14 , free sliding being ensured by the provision of the radiused end portions  34 ; 
         [0050]    the swivel connector  40  pivoting with respect to the body  30  about the axis C; and 
         [0051]    the eye  50  pivoting with respect to the boss  46 , and therefore the body  30 , about the swivel axis B. 
         [0052]    This allows a similar freedom of movement as does a conventional harness. 
         [0053]    As can be seen by comparing  FIGS. 9 and 3 , the effect of this invention is that the component of the force in the bridge  14  that is resolved into an inwardly-directed force F i  is reduced, and that the end potions of the bridge, which extend from the forward Ds  20 , are held at an angle which causes less or no compression to the user&#39;s legs. The effect of this is to lessen pressure that is applied to a user&#39;s body during use of the harness, and thereby reduce the likelihood that it will cause discomfort. 
         [0054]    An alternative embodiment of the invention is shown in  FIGS. 10, 11 and 12 . This embodiment includes a swivel connector  40  essentially the same as that described above. 
         [0055]    In this embodiment, first and second arms  60 ,  70  are pivotally connected by a pivot bolt  62  and nut  64  to the boss  46  such that each arm  60 ,  70  can pivot against a respective one of the spaced parallel surfaces of the boss  46 . Remote from the pivot bolt  62 , the arms fork, whereby a passage  66  through each arm is defined in a direction normal to the pivot axis C. Each passage  66  is closed by a cross-piece  68  of circular cross-section that extends across the fork parallel to the pivot axis C. A transverse bore  72  extends through the second arm  70  parallel to and close to the pivot bolt. Two bores  74 ,  76  extend through the first arm  60  parallel to and close to the pivot bolt. 
         [0056]    The arms  60 ,  70  can be disposed in a closed position ( FIG. 10 ) in which they are pivoted together about the pivot bolt  62  to reduce to a minimum the distance between the passages  66 . In this position, the bore  72  of the second arm is in alignment with one of the bores  74  in the first arm  60 , and a pin can be inserted into these bores  72 ,  74  to secure the arms  60 ,  70  in that position. Alternatively, the arms  60 ,  70  can be disposed in an open position ( FIG. 11 ) in which they are pivoted apart about the pivot bolt  62  to maximize the distance between the passages  66 . In this position, the bore  72  of the second arm is in alignment with the other one of the bores  76  in the first arm  60 , and a pin can be inserted into these bores  72 ,  76  to secure the arms  60 ,  70  in the open position. 
         [0057]    In use, the bridge  14  of the harness passes through the passages  66  in the two arms  60 ,  70 . A climbing rope is connected to the swivel connector, typically through a carabiner that passes through the eye  50 . The bridge  14  can slide through the passages  66  and over the cross-pieces  68 . While in use, a user can move the arms  60 ,  70  between their closed and their open position as required. In the closed position, a small attachment width on bridge  14  is created to maximize a user&#39;s freedom of movement. In the open position, the connection with the bridge is larger, thereby increasing the comfort of the harness. 
         [0058]    The cross pieces  68  may include rollers to reduce the friction applied by the arms as they pass along the bridge  14 . Another consequence of this to reduce wear on the bridge  14 . A similar arrangement may be provided in other embodiments. 
         [0059]    It will be seen that when the harness is bearing a user&#39;s weight and the arms  60 ,  70  are in the open position, the forces F B  applied to the arms  60 ,  70  by the bridge  14  urge them towards the closed position, this force being resisted by the pin  78  and the material surrounding the bores  72 ,  76 . In many embodiments of this general configuration, the assembly as a whole will be strongest when the arms  60 ,  70  are in the closed position. Therefore, it may be advantageous for the assembly to be configured such that the arms  60 ,  70  return to the closed condition if normal service loading is exceeded, and well before loading on the assembly approaches an ultimate maximum load. 
         [0060]    In this embodiment, a break-out portion  80  of the material of the first arm  60  that surrounds the bore  76  used when the arms  60 ,  70  are in the open position is of reduced thickness. The break-out portion  80  is located at the part of the first arm  60  that react force F P  with the pin  78 . The pin  78  will be driven though break-out region  80  in the event that the force F B  applied by the bridge  14  to the arms  60 ,  70  exceeds a threshold. With careful design of the thickness and position of material, this can be caused to happen at loads significantly below the ultimate failure load of the assembly (but in excess of that encountered in normal use) and relatively progressively, as compared with catastrophic failure that might occur in the event of breakage under extreme loading. 
         [0061]    The embodiment of  FIGS. 13 to 15  is functionally similar to that of the embodiment of  FIGS. 10 to 12 . In this embodiment, two arms  160  are pivotally connected to a central boss  140  that has a securing eye  142 . Although the boss  140  shown is a one-piece, solid component, it could equally be of a swiveling type, as described above. 
         [0062]    The arms  160  each comprises two parallel side plate members  162  connected to opposite sides of the boss  140  by a pivot  164  whereby the arms can pivot with respect to the boss  140  about respective parallel pivot axes. A guide ring  166  interconnects the arms  162  remote from the pivots, the guide ring  166  being free to pivot with respect to the arms  160  about an axis parallel to the pivot axes of the arms  160 . The guide rings  166  each have a rounded square shape and have inwardly convex curved surfaces to allow smooth passage of the bridge through them. The pivotal attachment of the guide rings  166  to the arms  160  ensures that they always adopt an alignment that allows free passage of the bridge  14  though them. 
         [0063]    The plate members  162  have first and second apertures  174 ,  176  with align with a transverse bore  172  in the boss  140  with, respectively, the arms  160  in a closed and an open position. To retain the arms  160  in either position, a pin  180  is inserted through the apertures  174  or  176 , as the case may be, and the bore  172 . The pin  180  can be selected to have a strength that will cause it to fail in the event that the load applied to the arms  160  by the bridge exceeds a threshold, thereby allowing the arms  160  to return to the closed position. 
         [0064]    The embodiment of  FIGS. 16 to 19  comprises a central boss  240  with two (in this case) securing eyes  242 ,  244  carried on a transverse flange portion  246 . Coaxial externally-threaded spigots  248  extend from the flange portion  246 , each having an axial through passage that also extends through the flange portion  246 . A respective sleeve  250  is carried on each of the spigots  248 , the sleeve having an internal thread in engagement with the thread of the spigot  248 . An outer face of each sleeve has an opening  254  in communication with its interior, the opening being surrounded by a concave curved surface. 
         [0065]    In use, the bridge  14  is passed through the sleeves  250  and the boss  240 . The length of the loading applied to the bridge  14  is determined by the distance between the openings  254  of the sleeves  250 , which can be adjusted by rotation of the sleeves  250  with respect to the boss to cause them to move axially along the spigots  248 . It may be advantageous for the threads of the two spigots  248  (and so, of the sleeves  250 ) to be of opposite hands, whereby the same action on the part of a user causes the same effect (lengthening or shortening) to each of the sleeves. 
         [0066]    A variation on the first embodiment of the invention is shown in  FIGS. 20 to 22 . In this embodiment, a slot  310  extends radially through each tubular passage  332  of the body  330 . Thus, the body is generally U-shaped in section. In the region of the end portions  334  of the tubular passage, flanges  312  project form the body, parallel and facing one another to opposite sides of each slot  310 . A bore extends through each flange  312 , the bores of each pair of flanges  312  being coaxial. A closing pin  316  is provided at each end portion  334 . In a closed condition, the closing pin  316  passes through both bores. The swivel connector  340  is secured between the flanges by a removable pivot pin  342 . 
         [0067]    With the pins  316  in the closed condition, and the swivel connector  340  retained by the pin  342 , a rope bridge passing through the body  30  is retained within the body  330  and a harness to which the load spreading assembly is attached will operate in the same way as the first embodiment. In an open position, each closing pin  316  is withdrawn, and both bores and the pivot pin  342  are removed to allow the swivel connector to be separated from the body  330 . In this configuration, a rope bridge  14  or other connecting element can pass into or out of the body  330 . This allows the apparatus to be applied to or removed from a harness without the need to free one end of the rope bridge. 
         [0068]    With reference now to  FIGS. 23 and 24  there is shown a modification that can be applied to many of the embodiments described above. This particular implementation of the modification is a variation of the embodiment of  FIGS. 4 to 8 , but the skilled person will readily understand how it could be applied to other embodiments. 
         [0069]    In this modification, the end portions  434  of the tubular body  430  are formed on separate annular components  436 . Each annular component has a central opening that, at an inner end, connects with one end of the cylindrical passage  432 , and, extending outwardly from there, is radiused so as to present no sharp edges and reduce frictional forces in movement of a rope or other element extending out of the end of the passage  432 . This is exactly the same function as described with reference to the end portions  34  of the first embodiment. 
         [0070]    The annular components  436  are each secured to the tubular body  430  by several (two, in this embodiment) cap screws  438  that pass through the annular components  436 . The stem of each cap screw  438  is received in a tapped hole in an end surface of the tubular body  430 , and the head of each cap screw  438  is received in a recess in the annular component. 
         [0071]    The annular components  436  are rotationally symmetrical. If, during use, wear occurs on part of an annular component  436  through rubbing contact with the bridge  14 , it can be removed from the body  430 , rotated and re-attached such that a different, unworn part of the annular component  436  makes contact with the bridge  14 . The annular components  436  can be replaced independently of other components of the harness in the event that wear has occurred at all possible angular locations.