TECHNICAL FIELD

[0001] The present invention relates to devices for transferring movement and for applying forces

[0002] The invention has been devised particularly, although not necessarily solely, in relation to gear assemblies such as jacks and chain blocks for transferring force to lift loads or operate for example solar tracking assemblies or for opening and closing gates.

BACKGROUND ART

[0003] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0004] Mechanical lifting devices such as jacks are typically relative heavy and bulky, in particular if the intended use of the jacks is carrying relative large and heavy loads or applying relative large loads. Thus, the greater the load that requires lifting, the bulkier and the heavier that the lifting device will be.

[0005] The above is particular true due the gear mechanism that are required for transferring and changing the direction of forces applied to the jack for lifting or applying a force.

[0006] Gear mechanisms incorporating, for example, worm gears provide a change in direction of rotational movement as well as a reduction in revolutions between a powered gear and a powering gear. A particular advantage of the gear mechanisms that incorporate worm gears is that it is possible to move relative heavy loads using drive means of relative low power. Moreover, worm gears may be used as braking arresters to stop movement of a particular machinery operatively connect to the worm gears. [0007] Due to the above mentioned advantages worm gears are typically used in heavy duty drive assemblies involving relative high forces and torques. For example, worm gears are typically used in cranes, wind mills, earthmoving machinery, among others.

[0008] However, gear mechanism incorporating worm gears (also referred to as gear worm sets) may be relative bulky and therefore not suitable for installing in gearboxes to be used in, for example, jacks or chain blocks that provide relative small spaces for incorporating the gear mechanisms.

[0009] Moreover, other disadvantages of worm gear sets is that the load applied during the intermeshing of the teeth of the worm gear sets is applied to a relative small number of teeth; thus, the surface area provided by the intermeshing teeth of the worm gear and the gear wheel is relative small. This can lead to early breakage of teeth of the worm gears due to the application of relative large loads on a relative small number of teeth.

[0010] It is against this background that the present invention has been developed.

SUMMARY OF INVENTION

[0011] According to a first aspect of the invention there is provided a worm gear set comprising a gear comprising a surface having at least one tooth and a worm gear having a section comprising a surface having at least one tooth; wherein a section of the gear that has the tooth comprises a concave surface for receiving the section of the worm gear to allow intermeshing of the tooth of the gear and the tooth of the worm gear.

[0012] Preferably, the worm gear comprises a cylindrical section having a particular radius, the radius being substantially the same or less than the radius of curvature of the concave surface of the gear.

[0013] Preferably, the worm gear set comprises a double enveloping worm gear set. [0014] Preferably, the worm gear comprises a centre section having the tooth, a first end and a second end, the centre section being located between the first end and the second end, wherein the first and second end sections of the worm gear are configured to have the particular radius.

[0015] Preferably, the centre section of the worm gear is configured as an hourglass wherein the largest radius of the hourglass has substantially the same value than the particular radius of the first and second end sections.

[0016] Preferably, the centre section of the worm gear comprises a thread defining a plurality of teeth arranged in a spaced apart relationship along the centre section of the worm gear.

[0017] Preferably, the thread defines an outer three-dimensional envelope.

[0018] Preferably, the height of the teeth of the thread vary so that the outer three- dimensional envelope defines an envelope shaped as an hourglass with its walls substantially parallel to the hourglass-shaped center section of the worm gear.

[0019] Preferably, the largest diameter of the hourglass shaped envelope defined by the thread of the worm gear has substantially the same value than the diameter of the first and second end sections of the worm gear.

[0020] Preferably, the thread comprises a helical thread.

[0021] Preferably, the helical thread comprises a right handed helical thread.

[0022] Preferably, the helical thread comprises either a single or a multiple thread.

[0023] Preferably, the gear comprises a wheel gear.

[0024] Preferably, the wheel gear comprises a circular body having two sides and a surface located between the two sides, the surface surrounding the outer periphery of the circular body. [0025] Preferably, the surface surrounding the outer periphery of the circular body comprises the concave surface.

[0026] Preferably, the radius of curvature of the concave surface is substantially identical or less than the particular radius of the first and second ends of the worm gear.

[0027] In a particular arrangement, the radius of curvature of the concave surface is 17 mm.

[0028] Preferably, the concave surface of the gear comprises a plurality of teeth arranged in a spaced apart relationship with respect to each other defining a thread extending along the outer periphery of the gear, wherein each tooth is slanted 5 degrees with respect to the normal axis perpendicular to the sides of the gear.

[0029] Preferably, each tooth comprises an inner edge abutted against the concave surface and an outer edge extending between the sides of the wheel gear.

[0030] Preferably, the outer edge of each tooth comprises a centre section and two outer sections.

[0031] Preferably, the centre section comprises a concave edge having a radius of curvature of 11.5 mm.

[0032] Preferably, the centre section is configured as an arc section of 50 degrees of a radius of curvature of 17 mm.

[0033] Preferably, radius of curvature of the inner edge of the arc section is 17 mm.

[0034] Preferably, radius of curvature of the outer edge of the arc section is 11.5 mm.

[0035] Preferably, each outer section comprises an outer edge configured as a curve having an inflection point. [0036] Preferably, the inflection point is located 5,3 mm from the outer side of the gear and .6 mm below the outer circumference of the gear.

[0037] Preferably, the thread angle of the thread of the wheel gear is 13.8 degrees.

[0038] Preferably, the space between the inner sides of the crests of adjacent teeth of the wheel gear is 4.15 mm.

[0039] Preferably, the angular distance between roots of adjacent teeth of the wheel gear is 4.5 degrees.

[0040] According to a second aspect of the invention there is provided a gear comprising a surface having at least one tooth, wherein a section of the gear that has the tooth comprises a concave surface for receiving a section of a worm gear to allow intermeshing of the tooth of the gear and at least one tooth of the worm gear.

[0041] Preferably, the radius of curvature of the concave surface is substantially the same or less than the radius of a cylindrical section of the worm gear.

[0042] Preferably, the gear comprises a wheel gear.

[0043] Preferably, the wheel gear comprising a circular body having two sides and a surface located between the two sides and surrounding the outer periphery of the circular body.

[0044] Preferably, the surface surrounding the outer periphery of the circular body comprises the concave surface.

[0045] Preferably, the radius of curvature of the concave surface is substantially identical or less than the radius of the first and second ends of the worm gear.

[0046] In a particular arrangement, the radius of curvature of the concave surface is 17 mm. [0047] Preferably, the concave surface of the gear comprises a plurality of teeth arranged in a spaced apart relationship with respect to each other defining a thread extending along the outer periphery of the gear

[0048] Preferably, each tooth is slanted 5 degrees with respect to the normal axis perpendicular to the sides of the gear.

[0049] Preferably, each tooth comprises an inner edge abutted against the concave surface and an outer edge extending between the sides of the wheel gear.

[0050] Preferably, the outer edge of each tooth comprises a centre section and two outer sections.

[0051] Preferably, the centre section comprises a concave edge having a radius of curvature of 11.5 mm.

[0052] Preferably, the centre section is configured as an arc of 50 degrees of a radius of curvature of 17 mm.

[0053] Preferably, radius of curvature of the inner edge of the arc is 17 mm.

[0054] Preferably, radius of curvature of the outer edge of the arc is 11.5 mm.

[0055] Preferably, each outer section comprises an outer edge configured as a curve having an inflection point.

[0056] Preferably, the inflection point is located 5,3 mm from the outer side of the gear and .6 mm below the outer circumference of the gear.

[0057] Preferably, the thread angle of the thread of the wheel gear is 13.8 degrees.

[0058] Preferably, the space between the inner sides of the crests of adjacent teeth of the wheel gear is 4.15 mm. [0059] Preferably, the angular distance between roots of adjacent teeth of the wheel gear is 4.5 degrees.

[0060] Preferably, the gear ratio of the gear set may be between 2,000 to 1 to 10,000 to 1.

[0061] According to a third aspect of the invention there is provided a worm gear comprising a cylindrical body having a centre section having the at least tooth, a first end and a second end, the centre section being located between the first end and the second end; the tooth extending radially outward form the centre section, wherein the is tooth is configured not to extend beyond the first end and the second end.

[0062] Preferably, the end sections of the worm gear are cylinders configured to have a particular radius.

[0063] Preferably, the centre section of the worm gear is configured as an hourglass wherein the largest radius of the hourglass is substantially identical to the particular radius of the first and second ends of the worm gear.

[0064] Preferably, the centre section of the worm gear comprises a thread defining a plurality of teeth arranged in a spaced apart relationship along the centre section of the worm gear.

[0065] Preferably, the thread defines an outer three-dimensional envelope.

[0066] Preferably, the height of the teeth of the thread vary so that the outer three- dimensional envelope defines an envelope shaped as an hourglass with its walls substantially parallel to the hourglass shaped center section of the worm gear.

[0067] Preferably, the largest diameter of the hourglass shaped envelope defined by the thread of the worm gear has substantially the same value than the diameter of the first and second end sections of the worm gear.

[0068] Preferably, the thread comprises a helical thread. [0069] Preferably, the helical thread comprises a right handed helical thread.

[0070] Preferably, the helical thread comprises either a single or a multiple thread.

[0071] According to a fourth aspect of the invention there is provided a gear assembly comprising a worm gear set in accordance with the first aspect of the invention.

[0072] According to a fifth aspect of the invention there is provided a gear assembly comprising a body and a gear mechanism contained within the body; wherein the gear mechanism comprises a wheel gear assembly and a worm gear operatively connected to the wheel gear assembly, the wheel gear assembly being adapted to move a support arm slideably attached within the body.

[0073] Preferably, the gear mechanism comprises the gear set in accordance with the first aspect of the invention.

[0074] Preferably, the wheel gear assembly comprises a primary wheel gear and a secondary wheel gear; the primary wheel being operatively connected to the worm gear and the secondary wheel gear adapted to be operatively attached to the support arm form moving thereof.

[0075] Preferably, the support arm comprises an elongated body comprising notches indenting into one of the sides of the support arm adapted to receive teeth of the secondary wheel gear.

[0076] Preferably, the notches are arranged in a spaced apart relationship with respect to each other along a side of the support arm.

[0077] Preferably, the support arm also comprises a plurality of openings that traverse the beam and are arranged in a spaced apart relationship with respect to each other along the length of the support arm. [0078] Preferably, for each pair of neighboring openings, the openings are offset with respect to each other.

[0079] Preferably, the body of the gear assembly comprises at least one aperture adapted to receive fastening means (such as a socket) of a drive means (such as a drill) for operatively connecting the worm gear to the drive means.

[0080] In an arrangement, the drive means comprises a cordless drill having a planetary gear including one or more planet gears and a ring gear.

[0081] Preferably, the gear ratio of the planetary gear may be between 5 to 1 to 125 to 1.

[0082] Preferably, the body of the gear assembly comprises a first section and a second section, and a first plate and a second plate, the first and second sections are configured for defining a chamber between both sections when the sections are joined together and the chamber is adapted to receive the gear mechanism.

[0083] Preferably, the first plate is attached to an outer side of the first section.

[0084] Preferably, the second plate is attached to an outer side of the second section, the second plate defining together with the outer side of the second section a spacing for receiving the support arm for operatively connecting the support arm with the secondary wheel and permitting movement of the support arm.

[0085] Preferably, the first and second plates are adapted for attachment of the ends of an axel for rotation the wheel gear assembly during operation of the gear assembly.

[0086] Preferably, each first and each second section comprises each an inner surface having a first indentation and a second indentation for receiving the gear mechanism.

[0087] Preferably, the first indentation is adapted for receiving the worm gear and the second indentation is adapted for receiving the wheel gear assembly. [0088] Preferably, the first indentation is located tangentially with respect to the second indentation.

[0089] Preferably, a passage joins together the first and second indentations to permit engagement of the teeth of the worm gear with the teeth of the gear wheel to transfer rotational movement between the worm gear and the wheel gear.

[0090] Preferably, each indentation comprises an aperture surrounded by a periphery comprising a curved rim for joining with the side walls of the indentation and each aperture traverses the first and second sections in order for sides of the gear wheel assembly traverse the first and second sections of the body of the gear assembly.

[0091] Preferably, one side of the primary wheel traverses the first section of the body of the gear assembly in order for this particular side to be located adjacent the first plate that is attached to the outer side of the first section.

[0092] Preferably, the another side of the primary wheel comprising the secondary wheel gear traverses aperture of the second section to permit engagement with the support arm to transfer the force applied by the drive means such as the drill to the support arm.

[0093] Preferably, the body is adapted to permit sliding movement of the support arm with respect to the body of the gear assembly.

[0094] Preferably, the second plate covers the outer surface of the second section of the box of the gear assembly and a spacer is located between the second plate and the inner surface of the second section; the spacer comprising an aperture for at least partially surrounding the secondary gear wheel.

[0095] According to a sixth aspect of the invention there is provided a gear assembly in accordance with the fifth aspect of the invention comprising a post having one end attached to the body of the gear assembly. [0096] Preferably, the gear mechanism comprises the gear set in accordance with the first aspect of the invention.

[0097] According to a seventh aspect of the invention there is provided a roof structure supported by a main post through an universal joint allowing the roof structure to be tilted towards any orientation with respect to the post, wherein the roof structure comprising at least one gear assembly in accordance with the sixth aspect of the invention, another end of the post of the gear assembly being attached to the roof structure via another universal joint

[0098] Preferably, there a plurality of gear assemblies in accordance with the sixth aspect of the invention arranged in a spaced apart relationship with respect to each other.

[0099] Preferably, each gear assembly comprises drive means for operating the gear assembly.

[00100] Preferably, the roof structure comprises solar panels.

[0010] ] Preferably, the roof structure is adapted to track the sun.

[00102] According to an eight aspect of the invention there is provided a solar tracking assembly comprising a post, a roof structure pivotally attached to the post, a gear assembly comprising a body and a gear mechanism contained within the body; wherein the gear mechanism comprises a wheel gear and a worm gear operatively connected to the wheel gear, the worm gear being adapted to receive drive means for operating the gear assembly, and the solar tracking assembly further comprises means for orientating the post with respect to the post, wherein the means for moving the post are operatively connected to the wheel gear.

[00103] Preferably, the gear assembly comprises a fastener operatively connected to the wheel gear and adapted for attachment of the roof structure.

[00104] Preferably, the fastener is spring loaded. [00105] Preferably, the solar tracking assembly further comprises a frame structure attached to the post having a first shaft for pivotally attaching a second shaft slideably attached to the roof structure.

[00106] Preferably, the gear mechanism comprises the gear set in accordance with the first aspect of the invention.

[00107] According to a ninth aspect of the invention there is provided a chain block comprising a gear assembly comprising a body and a gear mechanism contained within the body; wherein the gear mechanism comprises a wheel gear and a worm gear operatively connected to the wheel gear, the worm gear being adapted to receive drive means for operating the gear assembly, and the chain block further comprising means for receiving at least one chain, and a gear system for operatively connecting the chain to the wheel gear.

[00108] Preferably, the means for receiving the chain comprises a centre section, and upper and lateral guide sections surrounding the centre section and spaced apart from the centre section defining gaps for receiving the chain.

[00109] Preferably, centre section comprises a drive gear operatively connected to the wheel gear and rotatably attached to the centre section, the drive gear being adapted to receive the chain.

[00110] Preferably, the centre section comprises an upper portion and lower portion sandwiched between the upper portion of the gear assembly, the upper portion having a flange for defining a spacing for receiving the chain.

[00111] Preferably, the gear assembly comprises means for retaining the chain within the spacing.

[00112] Preferably, the means for retaining the chain comprises the lateral guide sections and a first flap section. [00113] Preferably, the first flap section is pivotally attached to the centre section at a location adjacent the upper guide section for displacement displaced between a closed condition and an open condition.

[00114] Preferably, the lateral guide section are pivotally attached to the gear assembly permitting selectively pivoting of the lateral guide sections between a closed and an open condition, in the open condition the lateral guide sections define a clearance for receiving of the chain and in the closed condition, the lateral guide sections close the clearances for retaining the chain within the spacing.

[00115] Preferably, the centre section comprises means for securing the lateral guide sections in the closed condition.

[00116] Preferably, the means for securing comprises a second flap section pivotally attached to the centre section permitting pivoting the flap section between a closed condition and an open condition.

[00117] Preferably, the guide sections comprise grooves for receiving sides of the second flap when the lateral guide sections and the flap section are in the closed condition.

[00118] Preferably, the gear mechanism comprises the gear set in accordance with the first aspect of the invention.

[00119] According to a tenth aspect of the invention there is provided a multi-use gear assembly comprising any of gear assemblies in accordance with the fourth aspect of the invention having a surface adapted to receive accessories for the gear assembly to function in different type of applications, the accessories being operatively connected to the gear mechanism of the gear assembly.

Preferably, the accessories may comprise any of : means for slideably attaching a support arm to the surface, a fastener and frame structure for attachment of a roof structure to allow pivoting movement of the roof structure with respect to the gear assembly, and a means for operatively connecting a chain to the gear mechanism of the gear assembly and means for retaining the chain attached to the surface. BRIEF DESCRIPTION OF THE DRAWINGS

[00120] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is a schematic top perspective view of a worm gear set in accordance with the present embodiment of the invention comprising a worm gear and a wheel gear.

Figure 2 is a schematic top view of the wheel gear shown in figure 1 ;

Figure 2a is a cross-sectional view of a detail of the outer periphery of the wheel gear shown in figures 9 and 10;

Figure 2b is a cross-sectional view of the wheel gear shown in figures 9 and 10;

Figure 3 is a schematic side view of the worm gear shown in figure 1 ;

Figure 4 is a schematic side view of the worm gear set shown in figure 1 ;

Figure 5 is a schematic cross-sectional side perspective view of the worm gear set shown in figure 1 ;

Figure 6 is a schematic top view of the worm gear set shown in figure 1 ;

Figure 7 is a schematic front view of the worm gear set shown in figure 1 ;

Figure 8 is a schematic cross-sectional side view of the worm gear set shown in figure 1 along the lines 7-7'; Figures 9 and 10 are views the worm gear and wheel gear of a particular arrangement of a worm gear set in accordance with the present embodiment of the invention.

Figure 11 is a front perspective view of a first arrangement of a gear assembly in accordance with an embodiment of the invention incorporating a support arm;

Figure 12 is a front view of the interior of the gear assembly shown in figure 11 with the support arm removed;

Figure 13 is a rear view of the interior of the gear assembly shown in figure 11 ;

Figure 14a is a side view of the gear assembly shown in figure 11 ;

Figure 14b and 14b' are top perspective views of the gear assembly shown in figure 11 in exploded condition;

Figure 14c is a is a front perspective view of the gear assembly shown in figure 11 with the front plate detached;

Figure 14d is a front perspective view of the gear assembly shown in figure 11 with the front plate attached;

Figure 15 is a top perspective view of a particular arrangement of a worm gear set of the gear assembly shown in figure 11 ;

Figures 16 and 17 are side views of the gear assembly shown in figure 11 being adapted to function as chain block;

Figure 18 are side views of the gear assembly shown in figure 11 being adapted to function as a jack;

Figure 19 is a side view of a solar panel assembly incorporating a gear assembly shown in figure 11 ;

Figure 20 is a front view of a solar panel assembly incorporating a plurality of gear assembly shown in figure 11 ; Figure 21 is a top view of the solar panel assembly shown in figure 20;

Figure 22 is a side view of a particular post and jack arrangement shown in figure 19 or 20;

Figure 23 to 28 are perspective views of a particular arrangement of a solar tracking assembly in accordance with the present embodiment of the invention having its roof structure in different orientations;

Figure 29 is a plan view of a second arrangement of the gear assembly in accordance with the present invention;

Figure 30 is a side view of the particular arrangement of a support frame of the solar tracking assembly shown in figures 23 to 28;

Figure 31 is a bottom view of the particular arrangement of the roof structure of the solar tracking assembly shown in figures 23 to 28;

Figure 32 is a detail of the rear view of the solar tracking assembly of the solar tracking assembly shown in figures 23 to 28;

Figure 33 and 34 are plan views of a third arrangement of the gear assembly in accordance with the present embodiment of the invention, respectively in open condition and closed condition;

Figure 35 and 36 are perspective side views of the gear assembly shown in figures 33 and 34;

Figure 37 is a perspective view of a particular arrangement of drills in accordance with the present embodiment of the invention to be operatively connected to the gear assemblies in accordance with the present embodiment of the invention for driving thereof;

Figure 38 is a perspective view of a particular arrangement of the planetary gear system in accordance with the present embodiment of the invention; Figure 39 is schematic plan view of a system for operating a gate using a particular arrangement of the gear assembly in accordance with the present embodiment of the invention; and

Figure 40 is schematic side view of a system for operating the gate shown in figure 39.

DESCRIPTION OF EMBODIMENT(S)

[00121] The present invention relates to devices for transferring movement and for applying forces. In particular, the invention relates to gear assemblies such as jacks and chain blocks for transferring force to lift loads or for example to operate machinery such as solar tracking assemblies, or for opening and closing gates.

[00122] Figures 11 to 22, figures 23 to 32, and figures 33 to 36 show particular arrangements of gear assemblies in accordance with the present embodiment of the invention. The gear assemblies comprise a gear mechanism incorporating a worm gear and a wheel gear wherein the worm gear is adapted to receive drive means such as electric motors or handdrills that may be releasable attached to the gear assembly for operation thereof.

[00123] The gear assembly 62 in accordance with the present embodiment of the invention is particular useful because it may be used for a plurality of applications by connecting to the body of the gear assembly particular accessories in order to define different type of gear assemblies to be used as jacks, chain blocks or to operate for example machinery such as solar tracking assemblies or opening and closing gates.

[00124] Figure 1 shows a particular arrangement of a worm gear set 10 in accordance with the present embodiment of the invention. The worm gear set 10 comprises a worm gear 12 and a wheel gear 14.

[00125] As shown in figure 1 , the worm gear 12 is mounted onto the wheel gear 14 to allow intermeshing of threaded surfaces 16 and 18 of the worm gear 12 and wheel gear 14. [00126] Referring now to figure 2, the wheel gear 14 comprises a circular body 20. The circular body 20 comprises two sides 22 and 24 and the threaded surface 18 surrounding the outer circumference of the circular body 20.

[00127] The threaded surface 18 is configured as a concave surface 18 having a particular radius of curvature. The particular value of the radius of curvature will depend on the particaurty dimensions of the worm gear 12 to be engaged with the wheel gear 14.

[00128] The concave surface 18 comprises two upper sections 26 and a curved section 28. The curved section 28 is located between the sides 22 and 24 of the wheel gear 14.

[00129] The concave surface 18 comprise a thread 30. The thread 30 is defined by a plurality of teeth 32 arranged in a spaced apart relationship with respect to each other along the concave surface 18 of the wheel gear 14.

[00130] In the particular arrangement shown in the figure 10, the teeth 32 are slanted 5 degrees with respect to the normal axis perpendicular to the sides 22 and 24 of the wheel gear 14.

[00131] Figure 2a shows the teeth 32 of the particular arrangement of wheel gear 14 depicted in figure 9 and 10.

[00132] As shown in figure 2a, each tooth 32 comprises an inner edge 34 abutted against the concave surface 18 and an outer edge 36 (also referred to as crest) adapted to be received between adjacent teeth of the worm gear 12. In the particular arrangement shown in the figures 9 and 10, the radius of curvature of the inner edge is 17 mm.

[00133] The outer edge 36 does not extend beyond the outer periphery of the wheel gear 14; in this manner the outer edge 36 is contained within the concave surface 18 such that no part of the teeth 32 (such as the crest of the teeth 32) extend beyond the two upper sections 26 of the wheel gear 14. [00134] The upper edge 36 comprises a centre section 38 and two outer sections 40. The upper edge of the centre section 38 is configured as a concave edge 42. In the particular arrangement shown in the figures 9 and 10, the radius of curvature of the concave edge 42 is 11.5 mm.

[00135] Furthermore, the centre section 38 is configured as an arc section 46 having its longer arc length abutting the concave surface 18 and its smaller arc length defining the centre section 38 of the tooth 32.

[00136] In the particular arrangement shown in the figures 9 and 10, the angle of the arc section 46 is 50 degrees of the imaginary circle fitting the concave surface 18 of the wheel gear and having a radius 17 mm. In this particular arrangement, the radius of curvature of the inner edge of the arc is 17 mm; and, the radius of curvature of the outer edge of the arc is 11.5 mm.

[00137] Referring to figure 2a, the centre section 38 is joined to the upper sections 26 of the wheel gear 14 via the outer sections 40. Each outer section 40 comprises an inner edge abutting the concave surface 18 of the gear wheel 14 and an outer edge 44. Each outer edge 44 is configured as a curve having an inflection point 48 separating a concave portion 50 and a convex portion 52 of the edge 44.

[00138] In the particular arrangement shown in the figures 9 and 10, each inflection point 48 is located 5.3 mm from the outer side 26 of the wheel gear 14 and 0.6 mm below the outer circumference of the wheel gear 14. And, each of the outer sections 40 starts at 3mm below the outer circumference of the wheel gear 14.

[00139] Referring now Figure 2b, as was mentioned before, the wheel gear 14 comprises a plurality of teeth 32 arranged in a spaced apart relationship around the outer periphery of the wheel gear 14. The particular arrangement of wheel gear 14 shown in the figures 9 and 10, is configured to have a thread angle of 13.8 degrees; the space between the inner sides of the crests of adjacent teeth 32 is 4.15 mm; and, the angular distance between roots of adjacent teeth 32 is 4.5 degrees. [00140] Referring now to figure 3. Figure 3 shows a side view of a particular arrangement of a worm gear 12 in accordance with the present embodiment of the invention.

[00141] As shown in figure 3, the worm gear 12 comprises a centre section 54, a first end 56a and second end 56b, the centre section 54 being located between the first end and the second end 56.

[00142] The end sections 56 of the worm gear 12 are cylindrical sections having a particular radius. The centre section 54 comprises a body that is shaped as an hourglass. The hourglass comprises to ends and a centre section; the two ends are configured to have the largest diameters of the hourglass. These largest diameters have substantially the same value of the diameter of the first and second end sections 56 of the worm gear 12.

[00143] The centre section 54 of the worm gear 12 comprises a thread 58 defining a plurality of teeth 60 arranged in a spaced apart relationship along the centre section 54 between the first and the second ends 56 of the worm gear 12.

[00144] The thread 58 is configured such that an imaginary three dimensional envelope is defined. For this, the height of the teeth 60 vary in such a manner as to define the hourglass shaped envelope. The side surfaces of the hourglass shaped envelope substantially parallel to the hourglass shaped centre section 54 of the worm gear 12.

[00145] In the particular arrangement shown in the figures 9 and 10, the height of the teeth 60 are such that the outer diameter of the hourglass shaped section envelope defined by the thread 58 has substantially the same value or less than the diameter of the end sections of the worm gear 12. In this manner, none of the crests of the teeth 60 extend beyond the diameter of the outer ends 56.

[00146] Furthermore, in the particular arrangement shown in the figures 9 and 10 of the worm gear set 10, the worm gear 12 comprises right handed helical thread. [00147] As was mentioned before, the worm gear 12 is adapted to be received within the concave surface 18 such that the worm gear is at least partially the surrounded by the outer periphery of the wheel gear 14 as is shown in figures 4 to 8, for example.

[00148] As can be best seen in, for example, figures 6 and 7, the worm gear 12 is configured so that the radius of the diameters of the ends 56 of the worm gear 12 is substantially the same or less than the radius of curvature of the concave surface 18. In this manner, no portion of the worm gear 12 extends beyond the upper portions 26 of the wheel gear 12.

[00149] In the particular arrangement shown in the figures 9 and 10 of the worm gear set 10, the radius of curvature of the concave surface is 17 mm and the radius of the ends 56 of the worm gear 12 is 16.5 mm.

[00150] The worm gear set 10 in accordance with present embodiment invention is particularly suitable for installation in jacks and chain boxes. This particularly true due to the fact that the wheel gear 14 comprises an outer peripheral surface that is configured as a concave surface 18 for receiving the worm gear 12. Further, the fact the radius of the worm gear is substantially the same or less than the radius of curvature of the concave surface 18 provides a worm gear set 10 that comprises a width which value does not extend to the value of the wheel gear 14. Thus, the worm gear set 10 may be positioned in relative small spaces such as the spaces that are typically available in jacks and chain boxes.

[00151] In particular arrangements, the gear ratio of the worm gear set may be between 400 to 1 to 10,000 to 1.

[00152] Referring now to figures 11 to 21.

[00153] Figure 11 shows a particular arrangement of a jack in accordance with an embodiment of the present invention.

[00154] The gear assembly 62 comprises a box 64 and a support arm 66. The support arm 66 is slideably attached within the box 64 permitting movement of the support arm 66 between an upper condition and a lower condition. By moving the support arm 66 from the lower condition to the upper condition (as shown in figures 16 and 17) it is possible to lift a load.

[00155] Further, the gear assembly 62 comprises attachment means 68 for attaching for example a chain 70 (see figure 16) to the box 64, of the gear assembly 62. The chain 70 may comprise a fastening means for holding an object that may be selectively lifted and lowered using the gear assembly 62 by moving the support arm 66 as mentioned above.

[00156] In the particular arrangement shown in figure 11 , the attachment means comprises a flange 72 extending from the body 64 of the gear assembly 62; the flange 72 comprises a plurality of openings 74 arranged in a spaced apart relationship with respect to each other. The openings 74 permit attachment of, for example, the chain 18. Alternatively, the flange 72 allows attaching gear assembly 62 to posts for lifting of loads.

[00157] As mentioned above, the fact that the support arm 66 may slide between an upper and a lower condition permits lifting a particular object that may be attached to the chain 70 - see figures 16 and 17. Alternatively, sliding of the support arm 66 allows tilting of roof surfaces (incorporating for example solar panels); this particular use of the gear assembly 62 is illustrated in figures 19 to 21.

[00158] Referring now to figures 12 and 13.

[00159] The gear assembly 62 comprises a gear mechanism 76 for transferring the rotational movement of a drive means such as a drill 78 (see figure 16) to a wheel gear assembly 80. The wheel assembly 80 comprises a primary wheel gear 14 and a secondary wheel gear 82 - see figure 13. The primary wheel gear 14 receives the rotational force from the drill 78. The secondary wheel gear 82 transfers the rotational force from the drill 78 to the support arm 66 as is shown in figure 13.

[00160] The drive means may be a hand held drill 78 as shown in figure 16 that may be temporarily operatively attached to the gear assembly. Alternatively, the drive means may comprise an electric motor 134 as shown in figure 32 permanently connected to the gear assembly 62.

[00161] Moreover, the drive means may comprise cordless drills 134a and 134b as shown in figures 37 and 38. As shown in figure 38, the particular arrangement of cordless drill 134b comprises a planetary gear train including a sun gear, a plurality of planet gears and a ring gear. In a particular arrangement, the battery of the cordless drill 134 may be charged by the electricity provided by solar panels. In an alternative arrangement, the planetary gear may comprise a single planet gear.

[00162] In particular arrangements, the gear ratio of the planetary gear may be between 5 to 1 to 125 to 1.

[00163] The wheel gear assembly 80 and the support arm 66 are adapted to be operatively connected for transferring the rotational movement of the drill 26 to the support arm 66.

[00164] As shown in figure 13, secondary wheel gear 82 comprises a plurality of teeth 83 and the support arm 66 comprises an elongated body comprising notches 67 indenting into one of the sides of the support arm 66. The notches 67 are arranged in a spaced apart relationship with respect to each other along the side of the support arm 66. The notches 67 are adapted to receive, during operation of the gear assembly 62, the teeth 83 of the secondary wheel gear 82. This particular arrangement allows moving the support arm 66 as the wheel gear assembly 80 rotates due to the rotational movement of the worm gear 12 driven by the drive means such as the drill 78.

[00165] Further, the support arm 66 also comprises a plurality of openings 69 that traverse the support arm 66 from the front to the rear of the support arm 66 and are arranged in a spaced apart relationship with respect to each other along the length of the support arm 66a. Each pair of neighboring openings 69 are offset with respect to each other. The openings 69 permit attachment of fastening means such as chains or hooks for attachment of the loads to the support arm 66 for lifting of the loads during operation of the gear assembly 62 - see figure 16. In a particular arrangement, the support arm 66 may comprise a foot 124 (see figure 18 to 20) for supporting the support arm 66 on the ground.

[00166] Moreover, in the particular arrangement shown in the figures, the gear mechanism 76 is adapted to convert rotational movement, applied to the gear mechanism 76 by the drill 78, to linear movement of the support arm 66.

[00167] Conversion of the rotational movement to linear movement is accomplished via the gear set 10 - see figure 18. A particular arrangement of the gear set 10 has been described in greater detail above. In the particular arrangement in accordance with the present invention shown in figures 11 to 15, the gear set 10 comprises a worm gear set 12 and the wheel gear assembly 80 defining the gear mechanism 76 incorporated in the gear assembly 62.

[00168] A particular arrangement of the gear mechanism 76 is shown in figure 13. As shown in figure 13, the gear mechanism 76 is operatively connected to the support arm 66 through the secondary wheel gear 82. In this manner, movement of support arm 66 occurs during rotation of the secondary wheel 82.

[00169] Rotation of the secondary wheel gear 82 occurs as the drill 78 applies rotational movement to the worm gear 12. For this, the body 64 of the gear assembly 62 is adapted to receive a drill 78 or other type of drive means in order to operatively connected the drill 78 with the worm gear 14; for the worm gear comprises at its end two pins 86.

[00170] Further, the particular arrangement of the gear assembly 62 shown in the figures comprises two apertures 84a and 84b located on the sides of the body 64 for receiving fastening means of the drive means such as the drill 78. For example, the fastening means of the drill 78 may comprise a socket adapted to receive the pin 86 of the worm gear 12. As shown in the figures, the worm gear 12 comprises to pins 86a and 86b extending outward from both ends of the worm gear 12. By applying rotational movement to any of the pins 86, the worm gear 12 rotates moving the wheel gear assembly 80, which is operatively connected to the worm gear 12 through the primary wheel gear 14 as is shown in figure 18. Rotation of the secondary wheel gear 82 induces linear movement of the support arm 66 operatively connected to the secondary wheel gear 82 through the teeth 83 and the notches 67.

[00171] As will be described below with reference to several applications of the gear assembly 62, the linear movement of the support arm 66 permits selectively lifting or lowering loads as well as, for example, tilting roof structures comprising solar panels for tracking of the sun to capture as much solar energy as possible.

[00172] Referring now to figures 14, figures 14a to 14d show a particular arrangement of a gear assembly 62 in accordance with the present embodiment of the invention in assembled and disassembled condition.

[00173] In particular, figure 14a is a side view of the gear assembly 62 in an assembled condition. As shown in figure 14a, the gear assembly 62 comprises a body 64 having a first section 88 and a second section 90, and a first plate 92 and a second plate 94. The first and second sections 88 and 90 are configured for defining a chamber between both sections 88 and 90 when the sections 88 and 90 are joined together. The chamber is adapted to receive the gear mechanism 76.

[00174] The first plate 92 is attached to the outer side of the first section 88.

[00175] The second plate 94 is attached to the outer side of the second section 90. The second plate 94 define together with the outer side of the second section 90 a spacing for receiving the support arm 66 for operatively connecting the support arm 66 with the secondary wheel 82 and permitting movement of the support arm 66.

[00176] As will be described below the first and second plates 92 and 94 are adapted for attachment of the ends of an axel around which the wheel gear assembly will be rotating during operation of the gear assembly 62.

[00177] Figures 14b and 14b' show jack in an exploded condition. As shown in figures 14b and 14b' the first and second sections 88 and 90 are substantially mirror images of each other. Each section 88 and 90 comprises each an inner surface 96 having a first indentation 98 and a second indentation 100 for receiving the gear mechanism 76. In particular, the first indentation 98 is adapted for receiving the worm gear 12 and the second indentation 100 is adapted for receiving the wheel gear assembly 14.

[00178] Further, the first indentation 98 is located tangentially with respect to the second indentation 100 and a passage 102 joins together the first and second indentations 100 and 98 to permit engagement of the teeth of the worm gear 12 with the teeth of the gear wheel 14 to transfer rotational movement between the worm gear 12 and the wheel gear 14.

[00179] Furthermore, each indentation 100 comprises an aperture 104 surrounded by a periphery 106 comprising a curved rim 107 for joining with the side walls 109 of the indentation 100. Each aperture 104 traverses the first and second sections 88 and 90 in order for both sides of the gear wheel assembly 80 traverse the sections 88 and 90 of the gear assembly 62.

[00180] In particular, one side of the primary wheel 14 traverses the first section 88 of the body of the gear assembly 62 in order for this particular side to be located adjacent the first plate 92 that is attached to the outer side of the first section 88.

[00181] Further, the another side of the primary wheel comprising the secondary wheel gear 82 traverses aperture 104 of the second section 90 to permit engagement with the support arm 66 to transfer the force applied by the drive means such as the drill 78 to the support arm 66.

[00182] Figure 14c shows the secondary wheel 82 engaged to the support arm 44 via the notches 67 of the support arm 66 and teeth 69 of the secondary wheel 82.

[00183] As mentioned before, the support arm 66 during operation of the gear assembly 62 is being displaced between upper and lower conditions. For this, the body 64 is adapted to permit sliding movement of the support arm 66 with respect to the body 64 of the gear assembly 62. As shown in figure 14c, the box 64 comprises a bar 106 spaced apart from the secondary gear wheel 84. The bar 106 extends along the outer surface of the second section 90 of the gear assembly 62 allowing the support arm to be located between the bar 106 and the secondary gear wheel 84 with the side of the support arm 66 opposite to the side comprising the notches 67 abutting the bar 106 and allowing to the support arm 66 to slide along the bar 106 during operation of the gear assembly 62. The presence of the bar 106 permits (1) upholding the support arm 66 against the secondary gear wheel 84 to allow engagement of the support arm 66 with the secondary gear wheel 84 and restricting movement of the support arm 66 parallel to the sides of the box 64 of the gear assembly 62.

[00184] Further, as shown in figure 14d, the second plate 94 covers the outer surface of the second section 90 of the box 64 of the gear assembly 62. A spacer 108 is located between the second plate 94 and the inner surface of the second section 90 and opposite the bar 106. As shown in figure 14b, the spacer 108 comprises an aperture 110 for at least partially surrounding the secondary gear wheel 82.

[00185] Moreover, the gear wheel assembly 80 is adapted to rotate within the box 64 of the gear assembly 62 during operation of the gear assembly 62. For this, the gear assembly 62 comprises an axis 112 extending from the second plate 94 to the first plate 92 traversing a conduit 114 that extends through the center of the gear wheel assembly 80 - see figure 14a. The axis 112 is attached to the first plate 92 and extends to the second plate 94 traversing at least partially the wheel gear assembly 80. A pin 1 16 extends from the second plate 92 towards the axis 112 for connection therewith. The pin 116 comprises a head 118 for fastening to the outer surface of second plate 92.

[00186] Furthermore, figure 14b shows a particular arrangement of the worm gear 12. As mentioned before, the worm gear 12, during operation of the gear assembly 62, rotates within the passage 98; to facilitate rotation of the worm gear 12 within the passage 98, the worm gear 14 comprises at each of its ends cylinder bearings 120.

[00187] In operation, the jack 10 may be used for, for example, lifting of loads. [00188] Figures 16 and 17 show a particular application of the jack 10. As shown in figures 16 and 17, a chain 70a may be attached to the fastening means 68 of the gear assembly 62 for receiving a load required to be lifted such as for example an engine out of a vehicle. Further, first ends of pair of chains 70b and 70c are attached to the support arm 66 and second ends of the chains 70b and 7c may be attached to, for example, an overhanging support structure. By applying rotational force to the gear assembly 62 through the drill 78. The gear assembly 62 may be raised from a lowered condition as shown in figure 16 to a raised condition as shown in figure 17; in this manner the load that is attached to the chain 70a may be raised. For example, the engine may be lifted out of a vehicle; also the engine may be lowering into the vehicle be lowering the gear assembly 62 to the position shown in figure 16.

[00189] Further, figure 18 to 21 show an alternative application of the gear assembly 62. In this particular application a post 122 may be attached to the body 64 of the gear assembly 62. Also, in this particular arrangement, the support arm 66 is adapted to stand on the ground; for this, the support arm 66 comprises a foot 124 adapted to rest on the ground.

[00190] As shown in figure 18, in particular in the illustration located on the left of figure 18, in the lowered condition the post 122 is located at the same level than the support arm 66, during operation of the jack 10, the gear assembly 62 moves along the support arm 66 lifting the post 122 from the lowered condition as shown in the left illustration to the upper condition as shown in the illustration located on the right of figure 18.

[00191] Figures 19 to 21 illustrate another particular use of the post and jack arrangement 132 shown in figure 18.

[00192] Figure 19 to 21 show a roof structure 126 adapted to be tilted using a plurality of arrangements described in relation to figure 18. In particular, the roof structure 126 is supported by a main post 128 through an universal joint 130 allowing the roof structure 126 to be tilted towards any orientation with respect to the post 128. [00193] Further, a plurality of post and jack arrangements 132 as described in connection to figure 18 are operatively attached to the roof structure 126 through universal joints 131. The upper end of the post 122 of each post and jack arrangements 132a and 132b is hingedly attached to the lower surface of the roof structure 126 via the joints 131.

[00194] As shown in figure 21 , the post and jack arrangements 132a and 132b are arranged perpendicularly with respect to each other and adjacent the post 128. Each post and jack arrangements 132a and 132b is attached to the post 128 via an ami 133. An end of the arm 133 is pivotally attached to the gear assembly 62 via a pivot joint 135 to permit movement of the gear assembly 62 along the support arm 66 during operation of the solar panel assembly. The other end of the arm 133 is attached to the post 128.

[00195] In this particular arrangement, the roof structure 126 may be tilted forward or rearward during lifting or lowering the post and jack arrangement 132b and sideways during lifting or lowering the post and jack arrangement 132a.

[00196] The particular arrangement shown in figures 19 to 21 is particular useful for roof structures (including solar panels) to track the sun to ensure the most solar power is received during an entire day by tracking the movement of the sun. Thus, the arrangement shown in figures 19 to 21 can be used for defining a solar tracking assembly comprising solar panels for capturing solar energy and converting the solar energy into electric energy for driving electric equipment and charging electric storage devices such as batteries.

[00197] In a particular arrangement, the drive means for operating the post and jack arrangements 132a and 132b may comprise electric motors 134 controlled by control means for operating the post and jack arrangements 132a and 132b for the roof structure 126 to track the sun.

[00198] In a particular arrangement, the control means for tracking the sun comprises light detectors permitting to detect variations in the light intensity and electric circuity operatively connected to the light detectors 136 and to the motors 134. This arrangement permits controlling operation of the motors 134 in order to tilted the roof structure 126 based on the variation of light intensity detected by the light detectors 136. For this the control system moves the roof structure 126 to ensure that the light received on each light detector 136 is about the same. The control means also comprises processing means to control the motors 134 based on the light detected by the light detectors 136.

[00199] Referring now to figures 39 and 40. Figures 39 and 40 depict a particular system using a gear assembly 62 of the type of shown in, for example, figure 11 for either closing or opening of a gate 194.The gate 194 pivotally attached to a surface permitting selective displacement between a closed and an open condition. In figure 39 the gate 194 for illustration purposes only, the same gate 184 is shown in the close and open condition. Further, the gear assembly 62 is operatively attached to the gate 194 as is shown in figures 39 and 40 for selectively displacing the gate 194 in the open and closed condition.

[00200] Referring now to figures 23 to 31.

[00201] Figures 23 to 31 show a particular arrangement of a solar tracking assembly 138 in accordance with a particular arrangement of the present embodiment of the invention.

[00202] The solar tracking assembly 138 comprises a roof structure 140 and a post 142. The roof structure 140 is pivotally attached to the post 142 via a support frame 144 to permit selectively displacing the roof structure 140 at any orientations with respect to the post 142. In this manner the roof structure 140 may be moved in order to follow the movement of the sun as can be appreciated in figures 23 to 28 that depict the solar tracking assembly 138 with the roof structure 140 located at particular orientations with respect to the post 142. This is particularly advantageous because it permits solar panels that may be attached to the roof structure 140 to capture the sun light during the entire day.

[00203] Further, the solar tracking assembly 138 comprises a particular arrangement of a gear assembly 62 in accordance with the present embodiment of the invention. This particular gear assembly 62 is secured to the post 142 and operatively attached to the support frame 144 permitting during operation of the gear assembly 62 to move the roof structure 140 for varying its orientation with respect to the post 142 as was described above.

[00204] Referring to figures 29 to 32, the operational connection between the gear assembly 62 and the roof structure 126 is accomplished through a spring loaded fastener 146. The fastener 146 is attached to the secondary wheel 82 (see for example figure 13) of the gear assembly 62 via a shaft 150 - see figure 32. The fastener 146 comprises a cylinder 148 having two ends adapted for attachment to the roof structure 126 via extensions 150 as is shown in figure 32. In this manner upon operation of the gear assembly 62 the roof structure 126 may rotate around the longitudinal axis of the post 142.

[00205] Further, as mentioned before, the roof structure 126 may be moved at any orientation with respect to the post 142; for example, as shown in figures 23 and 24, the roof structure 126 may be displaced to be slanted with respect to the gear assembly 62; alternatively, the roof structure 126 may be moved to be nearly parallel to the post 142 as is shown in figure 25. This particular movement of the roof structure 126 is accomplished by operatively connecting the roof structure 126 to the support frame 144.

[00206] As shown in figure 26, the support frame 144 comprises a lower base 152 for attachment to the post 142 and an upper support structure 154 for attachment to the upper surface of the gear assembly 62. The upper support surface 154 and the lower base 152 are joined together via a frame structure 156.

[00207] Referring now to figure 28, the frame structure 156 comprises a vertical shaft 158 extending from a location below the gear assembly 62 to a location above the gear assembly 62. The end 160 of the vertical shaft 158 that is located above the gear assembly 62 (the upper end 160) is adapted to be operatively attached to the roof structure 126 via a shaft 162. In particular, the shaft 162 has an end slideably attached to the roof structure 126 and another end pivotally attached to the upper end 160 of the vertical shaft 158. [00208] The above described connection between the support frame 144 and the roof structure 126 via the shaft 162 permits varying the angle formed between the roof structure 126 and the post 142 of the solar tracking assembly 138 by operating the gear assembly 62.

[00209] In particular, during operation of the gear assembly 62, rotation of the secondary wheel 82 of the gear assembly 62 rotates the shaft 150 to which the fastener 146 is attached (see figure 32). Rotation of the shaft 150 rotates the fastener 146 rotating the roof structure 126 around the post 142; and, as described above, rotation of the roof structure 126 around the post 142 varies the angle formed between the roof structure 126 and the post 142 due to the fact that the shaft 162 being connected to the support frame 144.

[00210] This allows the roof structure 140 including solar panels to track the sun by synchronizing the movement of the roof structure as was described above in relation to the solar tracking assembly depicted in figures 19 to 21.

[0021] ] Referring now to figures 33 to 36.

[00212] Figures 33 to 36 show another particular arrangement of the gear assembly 62 in accordance with the present embodiment of the invention. This particular arrangement of gear assembly 62 is adapted to function as a chain block used for lifting loads.

[00213] The gear assembly 62 shown in figures 33 to 36 comprises as center section 160 and an upper guide section 162 and a pair of lateral guide sections 164a and 164b. The guide sections 162 and 164 surround the centre section 160 and are spaced apart from the centre section 160 defining gabs 166. In particular, a first gap 166a is defined between the upper guide section 162 and two gaps 166b are defined at each side of the centre section 160 between the lateral guide sections 164 and the sides of the centre section 160.

[00214] In this manner, a clearance is defined between the guide sections 162 and 164 for receiving one or more chains to surround the centre section 160. As will be described below, the centre section 160 is adapted to drive the chain around the centre section 160 to permit lifting or lowering of load attached to the chain.

[00215] The centre section 160 comprises a drive gear operatively connected to the secondary wheel gear 82 of the gear assembly 62 and rotatably attached to the centre section 160. The drive gear 168 drives the chain(s) around the centre section 160 during operation of the gear assembly 62.

[00216] Further, the centre section 160 is adapted to receive the chain(s); for this, the centre section 160 comprises an upper portion 170 and lower portion 172 (see figure 35) sandwiched between the upper portion 170 and the surface 174 of the gear assembly 62.

[00217] Further, the upper portion 164 comprises an upper surface that extends beyond the lower portion 172. In this manner, a flange 176 is defined that extends above the surface 174 of the gear assembly 62. The flange 176 defines a spacing 177 for receiving the chain.

[00218] Furthermore, the gear assembly 62 shown in figures 33 to 36 comprises means for retaining the chain within the spacing 177. The means for retaining the chain comprises the lateral guide sections 164a and 164b and a first flap section 178.

[00219] The flap section 178 is pivotally attached to the centre section 160 at a location adjacent the upper guide section 162. The flap section 180 due to being pivotally attached to the centre section 160 is adapted to be displaced between a closed condition and an open condition. In the closed condition, the flap section 178 extends from the centre section 160 to the upper guide section 162 covering the clearance 166a. The upper guide section 162 and the flap comprises means for fastening the flap section 178 to the upper guide section 162 to retain the chain in the gab 166a. The means for fastening the flap section 178 comprises protrusions 180 and openings 182 for receiving the protrusions 180 adapted to be fastened to each other to impede the flap section 178 to disengage the upper guide section 162. [00220] Moreover, retention of the chain in the spacing 177 (defined by the flange 176 and the surface 174 of the gear assembly 62) is accomplished through the lateral guide sections 164. For this, the lateral guide section 164 are pivotally attached to the gear assembly 62 permitting selectively pivoting the lateral guide sections 164 between a closed and an open condition. In the open condition as shown in figure 33, the lateral guide sections define the clearances 166 permitting receiving of the chain. In the closed condition as shown in figure 34, the lateral guide sections close the clearances 166 for retaining the chain(s) within the spacing 177.

[00221] The centre section 160 comprises means for securing the lateral guide sections 164 in the closed condition. The means for securing comprises a second flap section 184. The flap section 184 is pivotally attached to the centre section 160 permitting pivoting the flap section 184 between a closed condition (see figure 35) and an open condition (see figure 36).

[00222] Further, the guide sections 164 comprises grooves 186 for receiving the sides of the second flap 184 when the lateral guide sections 164 and the flap section 184 are in the closed condition. In this manner, the lateral guide sections 164 are secured and retain the chain(s) around the centre section 162.

[00223] In operation, an operator, for example, may locate a chain around the centre section 160 and secure the chain around the centre section by pivoting the first flap section 178 and the lateral guides section 164 into the closed condition. Once the lateral guide section 184 are in the closed condition, the second flap section 184 may pivoted so that the sides 188 of the flap section 184 enter the grooves 186 of the lateral guide sections 164 to impede movement of the lateral section 184.

[00224] The gear assembly 62 in accordance with the present embodiment of the invention is particular useful because it may be used for a plurality of applications by connecting to the body of the gear assembly particular accessories in order to define different type of gear assemblies, for example, as shown in figures 11 to 22, figures 24 to 32, and figures 33 to 36 and 39. Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

[00225] Further, it should be appreciated that the scope of the invention is not limited to the scope of the embodiments disclosed.

[00226] Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.