FIELD OF THE INVENTION

[0001] The present invention relates to safety apparatus for use with sheaves and pulleys. More particularly, the present invention relates to a safety apparatus that prevents fingers and clothing from entering into an area adjacent to the sheave or pulley. Additionally, the present invention relates to a safety apparatus that can be mounted to the sheave or pulley and which is adaptable to the various orientations of the cable extending from the sheave or pulley.

BACKGROUND OF THE INVENTION

[0002] Pulleys and sheaves are used in a wide variety of onshore and offshore operations. In certain circumstances, the sheaves or pulleys can be supported from an overhead position so as to facilitate the ability to lift an object from a location so as to move the object to another location. In other circumstances, the pulleys or sheaves may extend in a horizontal orientation adjacent to a floor. In this configuration, the pulleys and/or sheaves can be utilized so as to adjustably position an object on the floor. During the use of such pulleys and sheaves, the operators will typically manipulate a line by pulling on the line. The use of the pulleys and sheaves facilitates the ability, by way of mechanical advantage, to direct an object to another location. Typically, operators will wear gloves while manipulating the line that extends over the pulley.

[0003] In some or certain circumstances, the worker associated with such pulleys may move their hands very close to the actual pulley. If the gloved hand should move too close to the pulley, there is a possibility of the glove being caught in the area between the line and the pulley. This can draw the worker's hand into the pulley. Under such circumstances, finger severing or impalement can occur. As such, a need has developed so as to provide a safety apparatus that effectively prevents the worker from ever encountering the situation where his or her fingers are drawn into the pulley.

[0004] As used herein, the term "sheave" can refer to a block, a pulley, or combinations thereof. The term "pulley" and "sheave" are used interchangeably herein. Additionally, the term "line" can refer to ropes, wire ropes, cords, cables and belts.

[0005] It is important to note that the operation of sheaves and pulleys can cause the line to extend at various angles. Under certain circumstances, there will be a relatively wide angle between the portions of the line that extend between the worker and the object to be manipulated. In other circumstances, the line will extend generally adjacent to the object to be manipulated. As such, any safety apparatus would have to be adaptable to the various orientations of line that are required in the particular applications.

[0006] In the past, various patents have issued relating to safety and protection devices for use with sheaves and pulleys.

[0007] For example, U.S. Patent No. 968,304, issued on August 23, 1910 to G. H. Winslow, describes a pulley guard. This pulley guard includes a shield in the form of a disc or plate having an upper portion provided with a slot terminating in an enlarged aperture to receive and lock over a headed stud or support. The disc or plate has a lower portion that covers the rotary member and is provided with a slot to slidingly engage the shaft of the rotary member. There is an aperture above the slot to afford access to the rotary member. A means is provided for adjusting and locking the plate in different positions on the support.

[0008] U.S. Patent No. 1,175,065, issued on March 14, 1916 to H. Kotten, provides a shaft and pulley guard. In particular, there is shaft guard, a means for vertically adjusting and supporting the shaft guard, a pulley guard formed in sections and having an interlocking engagement with one portion of the shaft guard, and a means for supporting and relatively adjusting the pulley guard sections transversely.

[0009] U.S. Patent No. 1,820,322, issued on August 25, 1931 to B. L. Polkosnik, teaches a pulley guard and banger. This pulley guard and hanger is stamped from a single piece of sheet metal so as to present a central bar member having extensions reaching in opposite directions at right angles from its ends. The bar is bent to produce an open loop extending outwardly. The extensions are looped to encompass the sides of the pulley. The free ends of the side loops are overlapped and secured to the junction of the connected ends.

[0010] U.S. Patent No. 4,114,473, September 19, 1978 to H. M. Pollak, describes guard for belt pulley. The guard includes a top wall for overlying a portion of the pulley's side face between the nips of the belt and the pulley. A side wall is connected to the top wall and extending generally at right angles therefrom. The guard has three projections on the side wall with each projection terminating in an arcuate end face juxtaposed to the inner diameter of one of the grooves of the pulley. Each arcuate end face on the projections has a center of curvature corresponding to the axis of rotation of the pulley. A mounting means is connected to one of the walls for mounting the walls in a position so that each of the projections enters one of the pulley grooves and one projection occupies substantially all the pulley grooves that are unoccupied by the belt.

[0011] U.S. Patent No. 4,139,064, issued on February 13, 1979 to D. R. Dobberpuhl, provides a belt guard for a rotary tiller. The guard encloses the belt and has its forward end pivotally supported on a bracket fixed to the engine by a fastener which also serves to retain a belt guide in place. The rear end of the belt guard is supported for swinging about the forward connection.

[0012] U.S. Patent No. 4,648,855, issued on March 10, 1987 to Palloch et al., discloses a belt guard for industrial sewing machines which includes a cover made of two cover halves that can be clasped together. The cover extensively covers a V-belt pulley part.

[0013] U.S. Patent No. 4,917,656, issued on April 17, 1990 to Sato et al., provides a rear belt guard for use in a sewing machine. The guard member is fixed to the table for covering a rear portion of a belt of the belt device that is exposed on the table. The guard member has an inclined wall upper portion provided with a notched recess for receiving the belt when the head is turned rearwardly. A cover member is openable and slidable over the notched recess. The cover member is urged by a spring in as direction to be closed.

[0014] U.S. Patent No. 5,180,343, issued on January 19, 1993 to M. A. Reed, discloses a pulley guard apparatus that can be mounted to an interior surface of projecting flanges mounted on the pulley structure. Arcuate discs are arranged in confrontation in an edge-to-edge relationship with outer edges of the first and second pulley flanges preventing the binding and abrasion of a pulley belt.

[0015] U.S. Patent No. 5,461,848, issued on October 31, 1995 to L. Anthony, provides as mower pulley guard for covering a wheel pulley. A semi-circular panel is positionable over the wheel pulley of the mower. A pair of lateral panels extend from opposed ends of the semi-circular panel and cooperate with a pair of mounting projections to secure the semi-circular panel to a pulley housing of the mower. The device cooperates with a cover plate of the mower to fully enclose the wheel pulley to preclude an entrance of debris into the pulley housing.

[0016] U.S. Patent No. 5,957,796, issued on September 28, 1999 to V. McLean, provides a belt guard having a main rear wall with two slots for engaging over a pair of shafts of the pump jack at the drive belt on the pulleys on the drive shafts. The rear cover portion includes a peripheral wall extending around the sides and top of the peripheral edge with the bottom of the cover panel being opened. A front panel portion fits over the rear cover panel with a lip engaging onto the peripheral wall to which it is secured.

[0017] U.S. Design Patent No. D540,256, issued on April 10, 2007 to J. R. Bullock., Jr describes a belt guard which includes a first housing that is hingedly connected to a second housing. Hinge pins can be utilized so as to fix the housings into a closed position.

[0018] U.S. PatentNo. 8,789,816 issued on July 29, 2014 to the present Applicant, describes a hand protector safety apparatus that is very effective in promoting the hand safety of users of such sheaves. This patent describes a safety apparatus that has a sheave with a surface extending circumferentially therearound, a first housing interconnected to the sheave, a second housing interconnected to the sheave and pivotally mounted to the first housing, and a line extending over the surface of the sheave and through the interior of each of the first and second housings. Each of the first and second housings has a hole formed at an end thereof opposite the sheave. The line has a first portion extending through the hole of the first housing and a second portion extending through the hole of the second housing. Bushings are respectively received within the holes of the housings.

[0019] In U.S. PatentNo. 8,789,816, it was found that there were certain difficulties in the assembly of the cable into the housings. It was necessary to thread the cable through each of the bushings so as to allow for the proper installation of the hand safety protection apparatus. Additionally, after continued use, it was possible that the locking connection between the hand protection safety apparatus and the sheave assembly could come loose. Additionally, the end surfaces of each of the housings at the bushing is rather flat. As such, it was found that there is a possibility of a hand becoming wedged between the flat end surfaces of the housing and the sheave. As such, a need developed so as to assure a secure assembly of the hand protection safety apparatus on the sheave assembly, to enhance the installation of the hand protection safety apparatus upon the cable, and to deflect hands away from the bushings and the cable at the proximity of the ends of the housings.

[0020] FIGURE 1 shows the hand safety apparatus in accordance with U.S. Patent No. 8,789,816. The hand protection safety apparatus 10 includes a sheave (not shown in FIGURE 1), a first housing 12 and a second housing 14. The sheave will be enclosed by first panel 16 and an opposite second panel (not shown in FIGURE 1). A shackle 18 is fixedly mounted to the top of the panel 16. The shackle 18 can be pivotable about a journal 20. The sheave and the hand protection safety apparatus 10 has an axis of rotation 22. The sheave can rotate about this axis of rotation. This axis of rotation 22 can include an axle that extends through the hand protection safety apparatus 10. In particular, the first housing is pivotally connected to the second housing 14 at this axis of rotation 22.

[0021] There is a cable 24 that is illustrated as extending through the housing 12 and around the sheave. In particular, the cable 24 includes a first portion that extends outwardly of an end surface 28 of the first housing 12. A bushing is affixed to this end surface 28 so as to provide a bearing surface upon which the cable 24 can slide. The cable 24 includes a second portion 32 that extends outwardly of the end surface 34 of the second housing 14. A bushing 36 is affixed to this end surface 34 so as to provide a bearing surface upon which the cable 24 can slide.

[0022] In normal use, a pulling force can be applied to either the first portion 26 or the second portion 32 of the cable 24. The pulling force that is applied to one of the portions 26 and 32 of the cable 24 will cause the other portion of the cable 24 to be drawn inwardly over and around the sheave located within the safety apparatus 10. If the worker is guiding the second portion 32 when a pulling force is applied to the first portion 26, the entry of the worker's hand into the areas at the sheave is prevented by the blocking caused by the end surface 34 and/or the bushing 36. This was intended to prevent any injury to the hand of the worker. The bushing 36 has an outer diameter only slightly greater than the outer diameter of the cable 24 so that the possibility of a glove being drawn into the interior of the second housing 14 is prevented. In other circumstances, when a pulling force is applied to the portion 32 of the cable 24, any worker that is grasping the first portion 26 would avoid any possible injuries because of the blocking effect caused by the end surface 28 and/or the bushing 30. Arrows 38 and 40 illustrate the movements of the housings 12 and 14 relative to each other. The second housing 14 can move between a position in generally parallel relationship to the first housing 12 to a position in which the second housing 14 is offset by 180° from the first housing 12.

[0023] In FIGURE 1 , the hand protection safety apparatus 10 is secured to the sheave by way of the center shaft of the sheave. The center shaft of the sheave can be removed and a pin or bolt can be inserted therein. The bolt will have a head at one end and a nut at the opposite end so as to secure the hand protection shape safety apparatus to the sheave. [0024] Experiments with the hand protection safety apparatus 10 of the prior art, as shown in FIGURE 1, found that the flat end surfaces 28 and 34 on the housings 12 and 14, respectively, could cause a worker's hand to be wedged thereagainst when the cable 24 draws a worker's hand in the proximity to either of the respective bushings 30 or 36. It was found that it was important to be able to properly deflect a worker's hand away from these flat end surfaces 28 and 34. Furthermore, there remained the possibility that as a worker's hand would be drawn around the outer surfaces of one of the housings 12 or 14, the workers hand could, in rare circumstances, enter the area between the top of the housing and the sheave. As such, it was found that there is a need to be able to deflect a worker's hand away from this area.

[0025] The installation of the bushings 30 and 36 was found to be quite difficult. Typically, it was necessary to thread the cable 24 through each of these bushings. This could be a long and tedious process. In others circumstances, the complex assembly of the bushings 30 and 36 into the end surfaces 28 and 34 of the housings 12 and 14 became unduly complicated. Any complication in installation tended to discourage workers from installing the hand protection safety apparatus of the present invention.

[0026] The simple nut-and-bolt configuration that is used to secure the hand protection safety apparatus 10 to the sheave assembly was found to loosen over extended periods of use. It will be appreciated that each of the housings 12 and 14 will pivot or rotate with respect to each other about the axis of rotation 22. This continuing pivoting and rotating tended to loosen the connection between the nut and the bolt and loosen the connection with the center shaft of the sheave assembly. As such, a need developed so as to create a secure connection between the hand protection safety apparatus and the sheave assembly. It is also important to create an assembly which not would not become loosened after extended use.

[0027] Another safety apparatus for use with sheave is the subject of U.S. Patent No. 9,188,204, issued on November 17, 2015 to the present Applicant. The safety apparatus has a first plate suitable for placement over one side of the sheave, a second plate suitable for placement on an opposite side of the sheave, and a carriage positioned at a periphery of the first and second plates. The carriage extends across a gap between the plates. The carriage is movable along the peripheries of the first and second plates. The carriage includes a first carriage and a second carriage which are independently movable with respect to each other. The carriage includes a first body, a second body, and a discoidal member pivotally mounted to the first and second bodies. The discoidal member has a hole suitable for allowing the cable of the sheave to pass freely therethrough.

[0028] The safety apparatus also suffered from certain deficiencies. The safety apparatus of U.S. Patent No. 9,188,204 was very difficult to assemble onto the sheave assembly. As a result of the difficulty of assembly, workers were often discouraged from trying to implement the safety apparatus. In other circumstances, if the safety apparatus was improperly assembled, then problems could occur related to safety. Further, after extended use, it is found that the various connections of the safety apparatus and the connections of the safety apparatus to the sheave assembly could become loose as a result of continued use, vibration and wear. Additionally, it is found that the carriages associated with the cable could go out of alignment and create certain frictional issues with respect to the cable. As such, it is important to develop a safety apparatus that would remain intact during continued use, would assure proper alignments, and could be easily assembled.

[0029] It is an object of the present invention to provide a safety device for sheaves and pulleys that effectively prevents impaling or severing of fingers.

[0030] It is another object of the present invention to provide a safety device for use with sheaves and pulleys which does not interfere with the standard operation of the pulley, sheave or block.

[0031] It is another obj ect of the present invention to provide as safety apparatus for use with sheaves and pulleys which is adaptable to various angles and orientations of the line with respect to the pulley.

[0032] It is a further object of the present invention to provide a safety apparatus in which the construction utilizes identical components.

[0033] It is a further object of the present invention to provide a safety apparatus in which the design is easily scalable to the various configurations of sheaves.

[0034] It is a further object of the present invention to provide a safety apparatus that is extremely light.

[0035] It is still a further object of the present invention to provide a safety apparatus that is easy-to-use, easy to manufacture, easy to install and relatively inexpensive.

[0036] It is another object of the present invention to provide a safety apparatus which can be easily assembled onto the sheave assembly.

[0037] It is object of the present invention to provide a safety apparatus which avoids loads on the cable.

[0038] It is a further object of the present invention to provide a safety apparatus that is adaptable between 0° and 180° of movement.

[0039] It is a further object of the present invention to provide a safety apparatus that follows the movement of the cable without binding.

[0040] It is still a further object of the present invention to provide a safety apparatus which assures a proper alignment of the guide bushing with the cable.

[0041] It is still a further object of the present invention to provide a safety apparatus which avoids the effects of wear, shock and continued use.

[0042] These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.

BRIEF SUMMARY OF THE INVENTION

[0043] The present invention is a safety apparatus for use with a sheave assembly having a cable extending therefrom. As used herein the, the term "sheave assembly" refers to snatch blocks, blocks, pulley blocks, or pulley housings. The term "cable" as used herein can be cable, line, rope, wire rope, or fiber rope.

[0044] The safety apparatus of the present invention comprises a first guard body adapted to be placed on one side of the sheave assembly, and a second guard body adapted to be placed on an opposite side of the sheave assembly. Each of the first and second guard bodies has a housing at a lower end thereof. The first and second guard bodies are angularly displaceable with respect to each other relative to an angular orientation of the cable extending from the sheave assembly. A first guide bushing is affixed in the housing. The first guide bushing has a channel formed on a surface thereof opposite the housing. A second guide bushing is also affixed in the housing. The second guide bushing has a channel formed on a surface thereof. The first and second guide bushings are juxtaposed against each other such that the channels thereof face each other so as to define an angular opening through which the cable can extend.

[0045] Each of the first and second guide bushings has a tapered outer surface so as to narrow in a direction away from the bottom of the housing. The annular opening has an inner diameter slightly greater than an outer diameter of the cable. Each of the housings of the first and second guard bodies has an inwardly extending tab. Each of the first and second guide bushings has a slot extending on an outer surface thereof. The slot serves to receives the inwardly extending tab therein so as to fix a position of the guide bushing with respect to the housing of the guard bodies. Each of the first and second guide bushings has at least one hole extending therethrough. The hole has a longitudinal axis that extends transverse to a longitudinal axis of the channel. The housing has an opening on a wall thereof that is aligned with the hole. A fastener extends through the holes of the first and second guide bushings and through the opening in the housing so as to secure the first and second guide bushings together in a fixed position within the housing.

[0046] The first guard body has a pair of planar surfaces extending outwardly of the housing. The pair of planar surfaces are in parallel relation to each other. One of the pair of planar surfaces is adapted to be placed on one side of the sheave assembly. Another of the pair of planar surfaces is adapted to be placed on an opposite side of the sheave assembly. The pair of planar surfaces of one of the first and second guard bodies is positioned inwardly of the pair of planar surfaces of the other of the first and second guard bodies.

[0047] Each of the pair of planar surfaces has a hole form therein such that the holes are axially aligned. A shaft extends through the holes of the pair of planar surfaces of the first and second guard bodies. The shaft is adapted to extend through the sheave assembly. The shaft has a threaded end. A bushing has a side positioned against the outer surface of the pair of planar surfaces. The threaded end of the shaft extends through and outwardly of the bushing. A nut is affixed to the threaded end of the shaft and secured against the bushing. In the preferred embodiment the present invention, the bushing has a ffustoconical configuration with a wide end positioned against the outer surface of the pair of planar surfaces and a narrow end adjacent to the nut. The bushing has a counterbore formed inwardly of the narrow end. A lock assembly is positioned in the counterbore. The lock assembly has two pieces. These pieces include grippers on the outside and ramp-wedge surface steps on the inside. The assembly grips into the softer surface of the flange nut in the counterbore face of the steel bushing as torque is applied to the drive flats of the flange nut. There also additional locking assemblies of a smaller diameter under the head of each of the fasteners. [0048] This foregoing Section is intended to describe, with particularity, the preferred embodiments of the present invention. It is understood that modifications to these preferred embodiments can be made within the scope of the present claims. As such, this Section should not to be construed, in any way, as limiting of the broad scope of the present invention. The present invention should only be limited by the following claims and their legal equivalents.

BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS

[0049] FIGURE 1 shows a perspective view of a prior art safety apparatus.

[0050] FIGURE 2 is a perspective view of one side of the safety apparatus of the present invention as applied to a sheave assembly.

[0051] FIGURE 3 is a perspective view of an opposite side of the sheave assembly of the present invention.

[0052] FIGURE 4 is a perspective view of the guide bushing as used in the safety apparatus of the present invention.

[0053] FIGURE 5 is an exploded view of the guide bushing as used in the present invention.

[0054] FIGURE 6 is an end view showing the installation of the guide bushing within the housing of the guard body of the present invention.

[0055] FIGURE 7 is a perspective view of the shaft is used in the safety apparatus of the present invention.

[0056] FIGURE 8 is a side elevational view of the locking assembly as used with the shaft of the safety apparatus of the present invention.

[0057] FIGURE 9 is a side elevational view of the nut as used on the locking assembly of the safety apparatus of the present invention.

[0058] FIGURE 10 is a cross-sectional view showing the bushing as used in the locking assembly of the safety apparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0059] Referring to FIGURE 2, there shown the safety apparatus 70 in accordance with the teachings of the present invention. The safety apparatus 70 is shown as installed on a sheave assembly 72. The sheave assembly 72 can be supported from an overlying structure by a shackle 74. A cable 76 extends over the pulley 78 of the sheave assembly 72, through the safety apparatus 10, and outwardly of the safety apparatus.

[0060] The safety apparatus 70 has a first guard body 80 and a second guard body 82. In FIGURE 2, it can be seen that the first guard body 80 has a first planar surface 84 on one side of the sheave assembly and a second planar surface 86 on an opposite side of the sheave assembly. Similarly, the second guard body 82 has a first planar surface 88 on one side of the sheave assembly 72 and an opposite planar surface 90 on an opposite side of the sheave assembly 72. The first planar surface 84 and the second planar surface 86 of the first guard body 80 will overlie the outer surfaces of the first planar surface 88 and the second planar surface 90 of the second guard body 82.

[0061] The first guard body 80 has a housing 92 at a lower end thereof. The second guard body 86 also has a housing 94 at a lower end thereof. The first guard body 80 and the second guard body 82 are angularly displaceable with each other relative to an angular orientation of the cable 76 as extending from the sheave assembly 72.

[0062] The housing 92 has a first guide bushing 96 and a second guide bushing 98 affixed therein. The first guide bushing 96 and the second guide bushing 98 are juxtaposed against each other within the housing 92 so as to define an annular opening 100 through which the cable 76 extends.

[0063] The housing 94 of the second guard body 82 also includes a first guide bushing 102 and a second guide bushing 104. Guide bushings 102 and 104 also juxtaposed against each other so as define an opening 106 through which the cable 76 extends. It can be seen that the guide bushings 96, 98, 102 and 104 have a tapered outer surface so as to narrow in a direction away from the bottom of the respective housings 92 and 94. The annular openings 100 and 106 have an inner diameter slightly greater than the outer diameter of the cable 76.

[0064] As will be described in greater detail hereinafter, each of the housings 92 and 94 has an inwardly extending tab 108. Also, each of the first and second guide bushings have a slot extending an outer surface thereof. The slot serves to receive the inwardly extending tab.

[0065] In FIGURE 2, there is a locking mechanism 110 which joins the first guard body 80 and the second guard body 82 to the sheave assembly 72. This locking mechanism is described in greater detail hereinafter in association with FIGURES 7-10.

[0066] FIGURE 3 shows the opposite side of the safety apparatus 70 of the present invention. In particular, the first guard body 80 has its planar surface 84 overlying the planar surface 88 of the second guard body 82. The guard bodies 80 and 82 are applied over the sheave assembly 72. FIGURE 3 further shows that the first guide bushing 96 and the second guide bushing 98 are installed within the housing 92 of the first guard body 80. Fasteners 112 are used to secure the guide bushings 96 and 98 in a proper position within the housing 92. The annular opening 100 is illustrated as being defined by semi-circular channels formed in the inwardly-facing surfaces is of the first guide bushing 90 and the second guide bushing 98.

[0067] Similarly, the guide bushings 102 and 104 are received within the interior of the housing 94 of the second guard body 82. Once again, there is an annular opening 106 that is defined by the semi-circular channels formed on the interface of each of the guide bushings 102 and 104. The guide bushings 102 and 104 are secured within the housing 94 through the use of fasteners 112.

[0068] FIGURE 3 shows that the locking mechanism 110 has a head 116 bearing against the outer surface of the planar surface 84 of the guard body 80. As will be described hereinafter, the head 116 is part of a threaded shaft which extends through the interior of the shackle assembly 72 and has a threaded end which emerges on the outer surface of the planar surface 84 of the first guard body 80.

[0069] As the cable 76 is payed out or payed in, the cable will travel freely through the channels of the guide bushings. Since the cable 76 can have various orientations with respect to the sheave assembly 72, the rotatability or angular displacement between the guard bodies 80 and 82 facilitates the ability to compensate for any changes in the orientation of the cable 76. In normal use, a pulling force can be applied to the cable 76. This pulling force will cause another portion of the cable 76 to be drawn inwardly toward the channels of the guide bushings. If the worker is guiding the other portion of the cable when a pulling force is applied to the cable, the entry of the worker's hands into the areas of the sheave assembly 72 is prevented by the blocking caused by the outer surfaces of the guide bushings. As such, any injury to the hands of the workers is prevented. Since the channels of the guide bushings define annular openings with a diameter only slightly greater than the outer diameter of the cable, there is no possibility of a glove being drawn into the interior of the sheave assembly 72. Any injuries are prevented by the blocking effect caused by the carriages. Furthermore, the tapered outer surfaces of the guide bushings assure that the hand will properly deflect away from the interior of the annular opening.

[0070] Additionally, each of the guard bodies 80 and 82 includes redirect tabs 114 and 116 at the upper end of the respective housings 92 and 94. These redirect tabs are designed to redirect body contact away from the cable 76 and away from the sheave assembly 72 should a hand travel along the outer surfaces of the housings 92 or 94.

[0071] The guard bodies 80 and 82 of the safety apparatus 70 form fit around the geometry of the sheave assembly 72. Each of the guide bushings 96, 98, 102 and 104 has an identical configuration. As such, only a single mold is required to make these components. Since each of these components has an identical configuration, there is no possibility of improperly joining the pieces together. Manufacturing cost is greatly reduced. The configuration of the safety apparatus 70 of the present invention is scalable to the size of the sheave assembly 72. The safety apparatus 70 is extremely light. The ability to manufacture the safety apparatus 70 through the use of injection molding techniques and polymer technology allows color to be molded therein. Various labels and safety information can be applied to the exposed surfaces on the exterior of the guard bodies 80 and 82.

[0072] With reference to FIGURES 2 and 3, as will be further described hereinafter, assembly of the safety apparatus can be accomplished by removing the shaft of the sheave assembly and replacing the locking mechanism 110 therefor. One of the guide bushings 100 and 104 is affixed to the housing 94 of the second guard body 82. Another guide bushing is affixed to the housing 92 of the first guard body 80. As such, the semi-circular channel which defines the annular opening 106 can overlie the cable 76. The planar surfaces 88 and 90 can be placed on opposite sides of the sheave assembly 72. The first guard body 80 can then be applied over the outer surfaces of the pair of planar surfaces 88 and 90 of the second guard body 82. The holes in each of these planar surfaces will be aligned with the axial opening of the sheave assembly 72. The locking mechanism 110, including the shaft, can then be installed through the rotational axis of the sheave assembly 72 and locked in place. Thereafter, the other of the guide bushings can slide into place, by virtue of the tabs 108 so as to reside over the cable 76. The guide bushings 102 and 104 are secured to each other through the use of the fasteners 112. Similarly, the guide bushings 96 and 98 are secured to each other within the housing 92 through the use of the fasteners 112.

[0073] In FIGURE 3, the fasteners 112 are rivnuts that are compressed into the holes in the guard housing so as to clamp the two halves of the guide bushing. There are threads in the center of the rivnut into which the fastener is screwed. As such, the safety apparatus 70 is easily installed over the sheave assembly 72.

[0074] FIGURE 4 is an isolated view showing the assembly of the guide bushings 96 and 98. It can be seen that there are holes 124 and 126 that extend through the square block portion 128 of the guide bushings 96 and 98. Slots 130 and 132 are formed on opposite sides of the guide bushings 96 and 98 so as to align with each other and also align the respective holes 124 and 126. Once assembled, the semi-circular channel 134 of guide bushing 96 will be aligned with the semi-circular channel 136 of the guide bushing 98 so as to define the annular opening 100. Annular opening 100 will extend entirely through the interior of the assembled guide bushings 96 and 98.

[0075] FIGURE 5 shows an exploded view of the guide bushing assembly of the present invention. It can be seen that the guide bushing 76 has pins 140 that are pressed- in the near the conical end of the guide bushings 96 and 98. These pins 140 are illustrated in a suspended fashion in this exploded view. The upper guide bushing 96 has two clearance pocket holes 124 and 126 drilled therethrough so as to allow the upper guide bushing 96 to mate with the lower guide bushing 98 and so that all the features are aligned together. Fasteners 112 will then extend through the holes 124 and 126 so as to engage with the corresponding and aligned holes 148 of 150 on the interface of the second guide bushing 98. Fasteners 112 can be in the nature of locating dowels pressed into the blind holes machined on the respective guide bushings. An anti-vibration lock washer assembly having a wedge-lock action can be placed on to the head of each of the fasteners 112 before the fastener is engaged with the opposite guide bushing and then turned clockwise so as to screw into the threaded rivnuts pressed into the end of each of the guard bodies. The arrangement of slots 130 and 132 assures a proper orientation of the assembled guide bushings 96 and 98 when they are placed within the housing. The corresponding pocket location/clearance holes on the guide bushing 96 is not illustrated in FIGURE 5 but would correspond to those two holes 142 on the lower guide bushing98.

[0076] FIGURE 6 shows how the assembled guide bushings 96 and 98 are affixed within the housing 92 of the guard body 80. It can be seen that there are inwardly extending tabs 108 on each of the sides of the housing 92. The slots 130 and 132 of the guide bushings 96 and 98 will receive these tabs 108 so as to allow one of the guide bushings 96 or 98 to be introduced into the interior of the housing 92. The fasteners 112 can then be tightened so as to establish a secure fit of the guide bushings in the interior of housing 92. [0077] Each of the guide bushings 96 and 98 can be formed of a UHMW material. The common shape of the guide bushings 96 and 98 are designed to open up and strip away a hand from reaching the pinch-point of the sheave assembly. The UHMW material has a low coefficient of friction. This eliminates the need for lubrication. This material is tolerant of ultraviolet light and it is also chemical resistant. As such, this material is suitable for use in offshore environments.

[0078] FIGURE 7 shows the shaft 160 as used in the locking mechanism 110. Shaft 160 includes a head 116 at one end thereof. Head 116 will have a shoulder which will bear against the other surface of one of the guard bodies. The shaft 160 also has threaded end 162 which will extend outwardly of the opposite side of the guard body. The shaft 160 will extend through the rotation axis of the pulley 78 of the sheave assembly 72. A locating pin 163 is located between the threaded end 162 and the shaft 160. The locating pin can be a spiral pin. The locating pin 163 prevents the pulley shaft from rotation in the side plate of the sheave block.

[0079] It is important in the present invention to provide a secure locking mechanism for the shaft associated with the sheave assembly 72 and with the safety apparatus 70 of the present invention. As such, the locking mechanism 110 of the present invention has a unique configuration. As seen in FIGURE 8, the locking mechanism 110 includes a hex flange nut 170 that can be threadedly affixed to the threaded end 162 of the shaft 160. A frustoconical bushing 172 will have an inner surface 174 which will be juxtaposed against the outer surface of one of the guard bodies. There is a lock assembly 176 that is received within a step counterbore machined into the outer end 178 of the bushing 172. The locking assembly 176 is located under the flange l80 ofthe hex flange nut 170. The hex flange nut 170 is then torqued to a prescribed setting. The outside surfaces of the lock nut of the locking assembly are shaped into a ramp in a counter-rotational angle. As the hex flange nut 170 is tightened on the shaft 160, its base surface rides over the small ramp features pointed in a clockwise direction. The turning motion is stopped once the prescribed torque over the small ramps is reached. This results in the locking assembly 176 having a wedge-lock action. It will sink into the contact base face of the hex flange nut 170 and the counter bore face of the bushing 172. Both of these materials are designed to be less hard than the washer set. The hex flange nut 170 cannot vibrate loose until the pressure is overcome by reverse rotational force greater than the installation pressure. This force will lift the inner opposing ramp faces apart and loosen the hex flange nut 170. This unique feature allows for the hex flange nut 170 to be removed for inspection without damaging the threads in the hex flange nut 170 and the threaded end 162 of shaft 160. The hex flange nut 170 can be easily affixed to the original pulley shaft 160 of the shiv assembly 72 by staking to prevent backing off in use. When the hex flange nut 170 is staked to the shaft 160, it cannot be removed without damaging both members. As such, it would make them both unsuitable for future use. The flange of the hex flange nut is designed never to make contact with the tapered bushing 172. The locking the two-piece locking assembly comes between the hex flange nut 170 and the bushing 172 so as to bite into the bottom of the flange nut and the bottom face of the tapered bushing. After the hex flange nut 170 is torqued down, there should be approximately a 0.030 clearance between the two. The locking mechanism 110 includes a hex flange nut 170 that can be threadedly affixed to the threaded end 162 ofthe shaft 160. A ffustoconical bushing 172 will have an inner surface 174 which will be juxtaposed against the outer surface of one of the guard bodies. There is also a lock washer assembly 176 that will be received within a step counterbore machined into the outer end 178 of the bushing 172. The lock washer assembly 176 is located under the flange 180 of the hex flange nut 170. The hex flange nut 170 is then torqued to a prescribed setting. The outside surfaces of the lock washer assembly are shaped into a ramp in a counter-rotational angle. As the hex flange nut 170 is tightened on the shaft 160, its base surface rides over the small ramp features pointed in a clockwise direction. The turning motion is stopped once the prescribed torque over the small ramps is reached. This results in the lock washer assembly 176 having a wedge-lock action. It will sink into the contact base face of the hex flange nut 170 and the counterbore face of the bushing 172. Both of these materials are designed to be less hard than the washer set. The hex flange nut 170 cannot now vibrate loose until the pressure is overcome by a reverse rotational force greater than the installation pressure. This force will lift the inner opposing ramp faces apart and loosen the hex flange nut 170. This unique feature allows the hex flange nut 170 to be removed for inspection without damaging the threads in the hex flange nut 170 and the threaded and 162 of shaft 160. The hex flange nut 170 can be easily affixed to the original pulley shaft 160 of the sheave assembly 72 by staking to prevent backing off in use. When the hex flange nut 170 is staked to the shaft 160, it cannot be removed without damaging both members. As such, it would make them both unsuitable for future use.

[0080] FIGURE 9 shows a side view of the hex flange nut 170 with the flange 180 located at a lower end thereof.

[0081] FIGURE 10 shows the bushing 172. Bushing 172 has a bottom surface 174 which can bear against the outer surface of the guard bodies of the safety apparatus 70 of the present invention. A passageway 184 extends through the interior of the bushing 172. The step counterbore 186 is illustrated as located at the upper side 178 of the bushing 172. The lock washer assembly can be received within the counterbore 186 so as to bear against the underside of the flange 176 of the hex flange nut 170.

[0082] The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.