Patent Publication Number: US-10309154-B2

Title: Height actuated self-activating safety gate

Description:
TECHNICAL FIELD 
     The subject matter described herein relates in general to automated safety equipment and, more particularly, to a height actuated safety gate that automatically extends and retracts according to a height of a lift. 
     BACKGROUND 
     Safety equipment can encompass a wide array of different devices. For example, different environments such as manufacturing facilities can include many different devices for electrical safety, fire safety, fall prevention, and so on. As one example, fall prevention equipment may include harnesses and tethers, safety railings, safety gates, and so on. However, many of these devices can be cumbersome and/or represent further difficulties. For example, some safety gates can have difficulties with pinch hazards from moving parts that engage the gates (e.g., swinging gates with a pivot point). In further examples, a gate swing arm and a work piece (e.g., manufacturing part) on a conveyor can form a pinch point when a manlift on which the gate is incorporated is in a lowered position. Moreover, the safety gates and other safety equipment can go unused when a worker is to remember that the particular device should be engaged before commencing work. Consequently, existing safety equipment, while useful in many respects, may still encounter difficulties. 
     SUMMARY 
     In one embodiment, a self-extending/retracting safety gate is disclosed. The disclosed safety gate is not, for example, dependent on the use of direct manipulation by a worker and, thus, can extend and retract when needed without manual manipulation. For example, in one aspect, the safety gate is implemented on a device that raises vertically from a floor. As such, in one embodiment, the safety gate is retracted providing access to a platform when in a lowered position on the floor. However, upon being raised above the floor, a gate movement assembly provided with the safety gate extends the safety gate to obstruct or otherwise close off an ingress/egress opening onto the platform. Thus, as the platform is raised, the safety gate provides automated safety by self-extending across the opening and providing for fall prevention of an operator. 
     In one embodiment, a safety gate for preventing falls from a platform is disclosed. The safety gate includes a housing that extends laterally from a back support attached to the platform. The housing is hollow. The safety includes a sliding member that is operable to (i) retract at least partially into the housing toward the back support to substantially conceal the sliding member within the housing and provide an opening beyond the housing for users to access the platform and to (ii) extend from an opening of the housing away from the back support to block access to the platform through the opening. The safety gate includes a gate movement assembly included at least partially within the housing between a rear portion of the sliding member and the back support, wherein the gate movement assembly is operable to cause the sliding member to extend from the housing and retract into the housing according to a height of the platform above a surface from which the platform raises. 
     In one embodiment, a gate connected to a platform is disclosed. The gate includes a housing that extends laterally from a back support attached to the platform, wherein the housing is hollow. The gate includes a sliding member that is operable to (i) retract at least partially into the housing toward the back support to substantially conceal the sliding member within the housing and provide an opening beyond the housing for users to access the platform and to (ii) extend from an opening of the housing away from the back support to block access to the platform through the opening. The gate includes a gate movement assembly included at least partially within the housing between a rear portion of the sliding member and the back support. The gate movement assembly is operable to cause the sliding member to extend from the housing and retract into the housing according to a height of the platform above a surface from which the platform raises. The gate movement assembly includes a connecting member attached to the sliding member at a first end and attached to an attachment point at a second end. The connecting member exerts a retracting force on the sliding member toward the back support when the platform is lowered toward the surface. The retracting force exerted by the connecting member is decreased as the platform is raised above the surface thereby permitting an extending force exerted by the gate movement assembly to extend the sliding member from the housing. 
     In one embodiment, a manlift is disclosed. The manlift includes a platform with railings connected thereto on at least three sides of the platform, the railings extending perpendicular from the platform to a railing height. The manlift includes a gate to selectively obstruct a side opening in the railings when the platform is raised above a floor surface and to retract to provide access through the side opening when the platform is lowered onto the floor surface, the gate comprising. The gate includes a housing that extends laterally from a back support attached to at least one of the railings. The housing is hollow. The gate includes a sliding member that is operable to retract at least partially into the housing toward the back support to substantially conceal the sliding member within the housing and to extend from the housing away from the back support to block access to the side opening of the platform while the housing supports the sliding member. The gate includes a gate movement assembly included at least partially within the housing between a rear portion of the sliding member and the back support. The gate movement assembly is operable to cause the sliding member to extend from the housing and retract into the housing according to a height of the platform above the floor surface from which the platform raises. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate various systems, methods, and other embodiments of the disclosure. It will be appreciated that the illustrated element boundaries (e.g., boxes, groups of boxes, or other shapes) in the figures represent one embodiment of the boundaries. In some embodiments, one element may be designed as multiple elements or multiple elements may be designed as one element. In some embodiments, an element shown as an internal component of another element may be implemented as an external component and vice versa. Furthermore, elements may not be drawn to scale. 
         FIG. 1  illustrates an isometric view of one embodiment of a platform with a safety gate. 
         FIG. 2  illustrates one embodiment of a gate housing and a sliding member with an external connecting member. 
         FIG. 3  illustrates another embodiment of a gate housing and a sliding member with an internal connecting member. 
         FIG. 4  is a side-view of one embodiment of a platform with a safety gate in a retracted position. 
         FIG. 5  is another side-view of one embodiment of a platform with a safety gate that is extended. 
         FIG. 6  illustrates an isometric view of one embodiment of a platform with a double safety gate. 
         FIG. 7  illustrates an isometric view of one embodiment of a dual-member safety gate with vertical attaching member. 
         FIG. 8  illustrates another embodiment of a gate housing and a sliding member with an integrated hard stop. 
     
    
    
     DETAILED DESCRIPTION 
     Systems, methods and other embodiments associated with a self-extending/retracting safety gate are disclosed. As mentioned previously, equipment operators and/or other workers may not use safety equipment when additional effort is needed to activate or otherwise implement use of the safety equipment. For example, when a manual gate needs closed a worker may leave the gate open because of forgetting to close the gate, an inability due to other tasks, and so on. Moreover, additional hazards can exist with some safety gates such as pinch hazards from pivots points where a gate swings open and shut. 
     Therefore, in one embodiment, a self-extending/retracting safety gate is provided. The self-extending/retracting safety gate is not dependent on direct manipulation by a worker and, thus, can extend and retract when needed without manual intervention. For example, in one aspect, the safety gate is implemented on a man-lift or another device that raises vertically from a floor. As such, in one embodiment, the safety gate is retracted providing access to the man-lift when the man-lift is in a lowered position on the floor. However, as the man-lift is raised above the floor, a gate movement assembly provided with the safety gate extends the safety gate to obstruct or otherwise close off an ingress/egress opening onto the man-lift. Thus, as the man-lift is raised, the safety gate provides automated safety by self-extending across the opening and providing for fall prevention of an operator. 
     In a similar, manner as the man-lift is lowered, the gate movement assembly is provided in such a configuration so as to, for example, automatically retract away from the ingress/egress opening. Consequently, the operation of the safety gate is automated according to a height of the man-lift, thereby removing interactions by a worker/operator. Additionally, in one embodiment, a particular configuration of the safety gate and sub-assemblies of the safety gate are implemented using mechanical means so that operation of the safety gate is improved to avoid electronic components and other complex mechanisms that can be prone to failure. 
     Referring to  FIG. 1 , one embodiment of a safety gate  100  is illustrated. As shown in  FIG. 1 , the safety gate  100  is illustrated in combination with a platform  105 . The platform  105  is, for example, a sub-structure of a lift, such as man-lift, or another device that functions to raise and lower workers, cargo, and so on from a floor  110 . Moreover, the platform  105 , in one embodiment, includes railings extending up in a perpendicular direction from the platform  105  and around a perimeter of the platform  105 . For various implementations, the railings  115  can be implemented with different configurations, such as with additional cross-members, additional supports or spindles, open sides of the platform  105 , as a solid side-panel, and so on. 
     In either case, the railings  115 , in one embodiment, define an ingress/egress opening  120  through which a worker/operator can gain access to the platform  105  when the platform  105  is lowered to the floor  110 . Additionally, the safety gate  100  can be attached to the railings  115  at one side of the opening  120 , as shown. Thus, the safety gate  100  can be integrated as part of the railing or added onto the railing  115 . 
     As further explanation of how the safety gate  100  functions, a connecting member (e.g., a cable) of the safety gate is connected to an attachment point  125  on a wall  130  or other fixed structure. It should be noted that while the attachment point  125  is illustrated as being fixed to the wall  130  behind the platform  105 , in general, the connecting member of the safety gate  100  need only be attached to some structure that is fixed in relation to the movement of the platform  105 . Thus, while the attachment point  125  is illustrated as being fixed to a separate structure from the platform  105  and associated man-lift, in various embodiments, the attachment point may be fixed to a support structure of the platform  105  that does not raise and lower, to other portions of the man-lift, and so on. Moreover, in one embodiment, the connecting member may be routed through a series of pulleys or other guides such that the attachment point is below a level of the safety gate  100 . 
     With either implementation, it should be appreciated that the safety gate  100  functions to self-extend and self-retract according to a height  135  above the floor  110 . Thus, initially, when the platform  105  is resting on or just above the floor  110 , the safety gate  100  is in a retracted position such that the opening  120  is not obstructed. Accordingly, when in this position of not being raised above the floor to a significant degree, the connecting member is tightened and applying a force that pulls the safety gate into a retracted position. However, as the platform  105  is raised above the floor  110 , the safety gate  100  extends into the opening  120  such that the opening  120  is obstructed by the safety gate  100 . In one embodiment, this self-extension of the safety gate  100  occurs because a distance between the safety gate  100  and the attachment point  125  of the connecting member decreases, thereby decreasing a force exerted on the safety gate  100 , at least temporarily, and permitting the safety gate to extend into the opening  120  according to an opposing force from an internal mechanism (e.g., spring, pneumatic cylinder, hydraulic cylinder, etc.). Consequently, as the height  135  increases, the safety gate  100  gradually extends to block the opening  120 . 
     As a further matter, an amount of travel and a rate of travel for the safety gate  100  is, in one embodiment, directly proportional to the height  135 . That is, because of the manner in which the connecting member is routed, the safety gate  100  gradually extends into the opening  120  proportional to the height  135 . Thus, once the platform reaches a height that is equal to an amount of travel provided for in the gate  100  within the opening  120 , the gate is fully extended and does not extend further as the platform continues to rise above the floor  110 . Similarly, as the platform  105  lowers toward the floor  110 , in one embodiment, the platform  105  reaches a height where the connecting member once again is under tension and begins to retract the safety gate  100  according to the height  135 . 
     Further explanation of the safety gate  100  will be provided in relation to  FIG. 2 .  FIG. 2  illustrates one embodiment of the safety gate  100  of  FIG. 1 . Accordingly, as illustrated, the safety gate  100  includes a sliding member  200  that is a moving/traveling component of the safety gate  100 . That is, the sliding member  200  moves into and out of a housing  205 . In one embodiment, the housing  205  is hollow and of a shape such that the sliding member  200  can substantially retract into the housing  205 . Accordingly, the sliding member  200  and the housing  205  may both be cylindrical in shape, rectangular, triangular, and so on. In further embodiments, the housing  205  and the sliding member  200  may have differing shapes so long as the sliding member  200  can retract into the housing  205 . Thus, in one embodiment, the sliding member  200  can retract into the housing  205  such that none of the sliding member  200  extends beyond the housing  205 . In another embodiment, an end portion of the sliding member  200  with a cap or other protrusion may extend beyond an opening of the housing  205  when the sliding member  200  is retracted. 
     Moreover, the housing  205  of  FIG. 2  is pictured with an internal spring  210 . The internal spring  210  is fixed to a rear portion of the sliding member  200  and provides an outward force in an extending direction onto the sliding member  200  when the sliding member is retracted into the housing  205 . For example, a slot  215  within a side of the housing  205  provides for connecting an attachment point  220  to the sliding member  200 . The attachment point  220  is coupled with a connecting member  225 . In one embodiment, the connecting member  225  is a cable or other device that provides a rearward tension force onto the attachment point  220  and thus also the sliding member  200 . As such, when the connecting member  225  is under tensioning force from, for example, the platform  105  being lowered to the floor  110 , the sliding member  200  compresses the spring  210  within the housing. In this way, the sliding member  200  is self-retracting according to a tension from the connecting member  225 . 
     Additionally, stored energy within the spring  210 , when the sliding member  200  is in the retracted position, provides for extending the sliding member  200  from the housing  205  when the tensioning force within the connecting member  225  is relaxed. For example, as the platform  105  of  FIG. 1  is raised from the floor  110 , tension within the connecting member  225  is relaxed since a distance between the attachment point  220  and the attachment point  125  decreases. This action provides for the spring  210  pushing the sliding member  200  from the housing  205  according to an extent to which the tension is relaxed. In either case, the attachment point  220  slides within the slot  215  in concert with the sliding member  200 . Moreover, the slot  215  can act as a stop for the sliding member  200  so that the sliding member is not pushed from the housing  205  by the spring  210 . It should be appreciated that, in general, the movement of the sliding member  200  occurs according to an imbalance in forces between an extending force produced by the spring  210  or other extending mechanism and a retracting force produced by tension in the connecting member  225  or other retracting mechanism. 
     Alternatively, as illustrated in  FIG. 3 , the connecting member  225  can be attached through a rear of the housing  205  to a rear attachment point  300  of the sliding member  200 . In this particular embodiment, the slot  215  with the attachment point  220  therein is replaced by the attachment point  300  and an opening at the rear of the housing  205  through which the connecting member  225  passes. In this way, additional pinch points that may cause injury to workers/operators of associated lifts are removed from the safety gate  100  to improve overall safety. Also, illustrated in  FIG. 3  is a guiding member  310  and a pulley  320 . The guiding member  310  is attached to a railing  115  or other structure (e.g., back support) at a rear of the housing  205 . The guiding member  310  can be a pulley, or other device that minimizes friction between the connecting member  225  and guiding member  310  while also providing support to the connecting member  225 . Additionally, the pulley  320  is in one embodiment, a tensioning pulley or take-up reel that includes a spring or other device which causes the pulley  320  to maintain a force on the connecting member  225  that is sufficient to uptake or otherwise reel-in slack of the connecting member  225  when the connecting member  225  is not under a load such as when the platform  105  is raised from the floor  110 . In either case, the pulley  320  is part of the attachment point  125 . 
     Furthermore, in one embodiment, the spring  210 , the connecting member  225 , the guiding member  310 , and the attachment point  125  comprise a gate movement assembly of the safety gate  100  that causes the sliding member to extend and retract according to a height  135  of the platform  105 . 
     A further example of how the safety gate  100  operates is shown in  FIG. 4  and  FIG. 5 . As an initial note,  FIGS. 4 and 5 , generally illustrate the housing  205  as being partially cutaway. As illustrated in  FIG. 4 , the spring  210  is compressed under a force provided via the connecting member  225  since the connecting member  225  is fully extended. Thus, a person  400  can ingress and egress through the opening  120  while the sliding member  200  is retracted. However, in  FIG. 5 , the spring  210  is at least less compressed than in  FIG. 4  and thus has exerted a force on the sliding member  200  to extend the sliding member  200  from the housing  205  in order to block the person  400  from falling from the platform  105 . 
       FIG. 6  illustrates a further embodiment of a safety gate as contemplated by this disclosure. As shown in  FIG. 6 , the platform  105  is equipped with an upper gate  600  and a lower gate  610 . Each of the gates  600  and  610  are generally similar to the gate  100  as previously described. Additionally, a further embodiment is illustrated in  FIG. 7  where the gates  600  and  610  are connected via a vertical cross member  700 . Moreover, as shown in  FIG. 7 , the platform includes railings  710  in addition to railings  115  so that a whole perimeter of the platform  105  is guarded from fall hazards. Thus, the railings  115  and  710 , in one embodiment, form a passenger compartment, or, part of a passenger compartment, of a manlift. 
       FIG. 8  illustrates one embodiment of a safety gate that is similar to the safety gate illustrated in  FIG. 3 . However, as illustrated in  FIG. 8 , the safety gate includes a hard stop attached to a bottom of the housing  205 . The hard stop extends into a groove within an underside of the sliding member  200 . Thus, the hard stop acts to retain the sliding member  200  within the housing  205  should the connecting member  225  snap or otherwise become disconnected. 
     Detailed embodiments are disclosed herein; however, it is to be understood that the disclosed embodiments are intended only as examples. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the various aspects herein in different arrangements to achieve the noted functionality. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an exemplary explanation of possible implementations. Various embodiments are shown in  FIGS. 1-7 , but the embodiments are not limited to the illustrated structure or application. 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. 
     It will be understood by one having ordinary skill in the art that construction of the described invention and other components are not limited to any specific material. Other exemplary embodiments of the invention disclosed herein may be formed from a wide variety of materials, unless described otherwise herein. For example, the housing  205 , the sliding member  200  and other components can be formed from various metal and/or metal alloys of steel, aluminum, and so on. In further examples, the components can be formed from rigid plastics, polymers or similar rigid materials. 
     As used herein, the term “coupled” (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated. 
     The terms “a” and “an,” as used herein, are defined as one or more than one. The term “plurality,” as used herein, is defined as two or more than two. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having,” as used herein, are defined as comprising (i.e. open language). The phrase “at least one of . . . and . . . ” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. As an example, the phrase “at least one of A, B, and C” includes A only, B only, C only, or any combination thereof (e.g. AB, AC, BC or ABC). 
     Aspects herein can be embodied in other forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope hereof.