FIELD OF INVENTION

This invention relates to a spring retractable reel with a gear assembly. More particularly, this invention relates to a heavy duty spring retractable reel with a compact gear module. Still more particularly, this invention relates to a heavy duty spring retractable reel with a compact gear module to optimise the reel rotations.

BACKGROUND ART

The following references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the following prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

The modern heavy duty spring retractable reel has its origins in industrial grade spring retractable reels developed after WWII, although earlier variants can be found as early as the mid 1 20's. They have been described as being manufactured in steel and powered by a standard range of spring motors which are typically supplied by a small number of high profile spring manufacturers. These reels have differed little over this time and are more commonly found today in applications that demand the ability to manage a range of hose types, ranging from smaller sized hose and cable up to 50mm diameter hose. In cases of such large hose diameters, the use of stronger steel materials has allowed for the accommodation of larger and heavier hose without failure. In all instances, the spring motor is mounted about the centre axis of the spool hub.

Such prior art heavy duty steel reels may be distinguished from the more common light duty plastic type spring retractable reels, the latter of which have emerged over the last 20 or so years with advances in injection moulding technology and the ability to produce large component mouldings. Plastic spring reels will typically be found in light duty hose storage applications, such as home, garage or handyman applications, for example, storing light and small diameter air hose or garden type hose. Although their use can venture into commercial and industrial applications, their typical service life limitations generally exclude their use for moderate to heavy duty reel applications.

A strong market therefore still exists for the traditional style of heavy duty steel spring reels in industrial, mining and other commercial applications, where larger hose is encountered and more arduous duties are demanded. These larger and heavy duty type steel reels are almost mandatory from a service life perspective. However, there are some specific deficiencies that have continued to restrict the further expansion of their application. Using standard gearing assemblies to control rotational speed in spring-powered reels has proved problematic as the size and weight of prior art gear boxes have been excessive for certain applications where compactness and weight are important considerations, such as in portable utilities.

Furthermore, spring-powered reels are typically made to high tolerances and cheaply, permitting an allowable amount of eccentricity and looseness between component parts aligned along the reel or hub shaft. This makes them unsuitable for fitment with gearboxes requiring low tolerance fits for good torque transfer. This has meant non-spring powered, electrical, hydraulic or air powered variants are preferred to manage heavy duty reels. Such variants are costly to manufacture and involve the expense and/or convenience of a connection to a suitable power source.

These application restrictions have not been addressed over a long period (over 50 years) of use of spring-powered reels. In simple terms, the unsuitability of spring powered hose reel retraction systems to a variety of heavy duty applications has related to the capacity of the spring types adopted for such uses to rewind longer lengths of hose. The basis for this may include the inherent restrictions of the typical range of spring motors conventionally used to power such devices. Also, the standard spring reel chassis architecture adopted for such uses is the alignment of the reel spool and power source on the same axis as the spool axle.

The capacity of these spring motors that can be used in such applications is usually restricted by the allowable radial size, width and weight of the spool, which in part determines the required spring mass. As such, the evolution of the heavy duty reel "spring" and its physical limitations have placed parallel limits on the hose length capacity of these reels. It should be noted, however, that the limiting factor has not only been the torque required. An abundance of torque can be obtained with single of multiple spring configurations. However, it is the number of useable turns available that is also a consideration, whilst satisfying minimum torque requirements. Accordingly, it would be advantageous to significantly increase and optimise the ability for such a reel to store and rewind more hose and to effectively allow more reel spool turns per available spring turns.

An object of the present invention is to ameliorate the aforementioned disadvantages of the prior art or to at least provide a useful alternative thereto.

STATEMENT OF INVENTION

The invention according to one or more aspects is as defined in the independent claims. Some optional and/or preferred features of the invention are defined in the dependent claims.

Advantageously, there may be provided a readily adaptable device that can be retrofitted to standard hose reel configurations in service, using the standard springs available.

Accordingly, in one aspect of the invention there is provided:

A gear assembly for a heavy duty spring motor comprising a spring having multiple turns about a spring drive shaft, the spring motor adapted to be mounted to a reel having hose to pay out or recoil back in, the reel mounted on a frame supporting a spool of the reel so that the spool rotates about a hub shaft, the frame adapted to support the spring motor, wherein the gear assembly operably modifies the ratio of turns of the spring motor relative to the rotations of the spool.

The heavy duty spring motor comprises a spring wound about the spring drive shaft, the spring motor adapted to be mounted to a reel having hose to pay out or recoil back in. Preferably, the gear assembly is a planetary gear set.

The heavy duty spring motor may include a concentric spring arrangement about the hub shaft of the reel.

According to a preferred form of the invention, the spring reel may form part of a spring reel cassette, optimised in its arrangement and preferably for the particular application.

Optimisation may involve a drive speed multiplier. The drive speed multiplier may be facilitated by specially adaptable gear sets. The gear sets may have ratios that can be tuned or formed to be suitable for specific spring combinations. For example, the gear set may have a gear with a 1 :2 ratio, one spring rotation equalling two spool rotations, for example involving a 25 teeth sprocket driving a 50 teeth sprocket. The gear set device may be adapted to float between the spring motor and the spool input shaft so as to not apply any extra drive train fractional loads.

With this increase in speed caused by the multiplier gear ratios, it is desirable to affix a spool speed control device. This is preferably adaptable to be retrofitted on a standard reel. Such a device may be found described in Applicant's published specification No. WO2011/072337.

The hose rewind speed control so described is suitable for delivering a safe rewind function.

The speed control device may be a brake device. The brake device may be mounted to the reel frame whereby some play about the shaft and/or axially is permitted to allow a high tolerance fit that permits lower, cheaper production values. The degree of play may be minimal and may be of the order of 0.2 - 2 mm..

Typically the speed multiplication will result in a torque reduction. However, for most uses, standard spring motors have excess torque. With appropriate tuning of the gear ratios to suit the spring type, there can be made available an optimised increase in spool capacity. A gear ratio may be lowered to accommodate a low torque spring or large reel load requirement, or raised where a high torque spring or low load reel is used. As an adjunct, an extra spring motor can be added to satisfy high torque requirements to accommodate the required number of spool turns. This, in turn, may accommodate long hose capacities within the same type of traditional spring reel architecture.

The gear assembly is preferably .compact, and still more preferably, axially compact. The gear assembly may be in the form of a discreet module that can be retrofitted to existing reels. The gear assembly is adapted to float and permit a minimal amount of play. The play may be about the hub shaft and the spring drive shaft, both axially and radially. In contrast, the spring motor is rigidly mounted to the reel frame. The gear module may comprise a pair of parallel spaced opposed planar plates that present an extremely slim or narrow form in end view. Sandwiched between the plates may be a gear set. The gear set may lie in a generall single plane. The plates and the gears may lie in parallel planes. The plates may be mounted to the each other by pins extending there between. The pins may be covered by sleeves. The plates may receive the pins or sleeves in over-sized apertures to permit some play. The gear assembly may comprise keyed sockets to receive the hub shaft and the spring drive shaft. The sockets may be coaxial with each gear in the gear set. The addition of the spring reel cassette, optimised according to a preferment of the invention, may therefore extend the use of spring powered reels to an expanded range of heavy duty spring reel applications, using existing architecture, devices and hardware. According to a preferred embodiment of the invention, the spring motor is not necessarily mounted concentrically about the spool hub axis, but may rather be mounted eccentrically. Such an arrangement is a significant departure from the prior art.

The spring motor housing or drum may house a pawl operatively connecting the spring to the drive shaft. The pawl may be a floating pawl. The floating pawl may engage the reel hub shaft. Accordingly, the spring housed with the spring motor assembly is floating and permitted move with a suitable amount of play. However, the drum housing the spring is rigidly mounted to the drive shaft.

The invention preferably provides for the spring motor to be coupled to a reel via a speed multiplier, preferably using a speed control top regulate uptake of the hose on the reel. The preferred form of the invention includes an eccentric spring mounting. An interconnecting gear set is preferably combined with a heavy spring with a high torque capacity to produce the required number of spool turns. In this case, the larger gear is the drive gear that is connected to the spring and the smaller gear is connected to a reel shaft. Thus, it is the driven gear that produces the speed multiplication to deliver more spool turns and accommodate a longer hose length.

The gear ratios can be reversed to multiply the torque capacity of the spring motor. In this instance, the number of available spool turns is reduced. Such a deficiency can be addressed by employing an appropriate high turn spring with a low torque.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood from the following non-limiting description of preferred embodiments, in which:

FIG. 1 is a front view of a standard concentric large spring reel;

FIG. 2 is a side view of the standard concentric large spring reel shown in FIG. 1;

FIG. 3 is a perspective view of the standard concentric spring reel shown in FIG. 1, but with a spring removed;

FIG. 4 is a side view of an eccentric large spring reel cassette;

FIG. 5 is a side view of reel having an alternative eccentric spring reel optimiser cassette; FIG. 6 is a front end view of the eccentric spring reel optimiser cassette on the reel show in Fig. 5 but with a brake;

FIG. 7 is a perspective view of the eccentric spring reel optimiser cassette on the reel shown in Fig. 5, but with spring removed;

FIG. 8 is a perspective view of the eccentric spring reel optimiser cassette shown in FIG. 5, but with cover off; and

FIG. 9 is a front end view of reel having a triplet of cassettes, including gear, brake and spring motor cassettes.

DETAILED DESCRIPTION OF THE DRAWINGS

Preferred features of the present inventi on will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention.

Turning to Figure 1, there is provided a reel assembly 10 comprising: a spool 20 with a hub 30 rotatably mounted on a hub shaft 32; a spool hub 22 from which extends a riser 24 for delivering fluid to a connected hose (not shown), with fluid supplied through the hub shaft 32; large spool disc walls 26; a level winder mechanism 40; and a heavy duty concentrically mounted spring drive 50 in a cassette or modular form for easy installation and retrofitting, all mounted on a reel base 12 from which upwardly extends a reel frame 14.

As shown in Figure 2, the cassette 50 is mounted concentrically relative to the hub shaft 32 and spool disc walls 26. The concentric cassette 50 may comprise a planetary gear set as a multiplier of the drive derived from the concentric spring arrangement 50.

In Figure 3 there is shown the reel 10 with the concentric spring cassette 50 removed to illustrate the mounting of the hub drive shaft 32. The hub drive shaft 32 is mounted in a U- shaped cradle 16, being a cut out from a frame wall 11 '. The frame wall 1 V is one of two upright frame walls 11,11' extending from the base 12 and being spaced apart to receive the hub shaft 32 and spool 20 there-between. The hub shaft 32 and spool 20 are supported by the frame walls 11,11'. The base 12 includes long slots 13 to enable the base 12 to be mounted on a structure, such as a floor or wall of a building or mobile unit.

In Figure 4 there is shown an eccentric heavy duty spring reel cassette 150 mounted to a reel 110. The reel 110 is substantially identical to the reel 10 of the first embodiment, and the eccentrically mounted spring cassette 150 is contained in a drum 152 and mounted on an axis that is parallel to the hub shaft 32 axis and offset therefrom.

In Figures 5 and 6 there is ^' shown embodiments of the invention in which there is provided a spring motor 250 having a smaller capacity for spring rotations compared to the spring motor 150 of the second embodiment shown in Figure 4. Again, the spring cassette 250 is eccentrically mounted, but the spring motor drive shaft 252 is positioned diagonally below the hub shaft 32.

Referring specifically to a stacked cassette arrangement shown in Figure 6, the third embodiment shown in Figure 5 is further augmented by the addition or insertion of a brake mechanism in a drum or cassette 270 that is interposed between the spring motor 250 and a planetary gear assembly 280 in stacked relationship. The brake cassette 270 is of the type described in the Applicant's published specification No. WO2011/072337 (equivalent to Australian Patent Application No. 2010333713). The brake cassette 270 is mounted to the hub shaft 32 to allow adequate play and permit compatibility with high tolerance manufacture. The brake cassette 270 is sandwiched between the rigidly mounted spring housing and the loosely mounted brake module comprising the planetary gear assembly280.

The planetary gear assembly 280 includes a multiplier arrangement that transfers the torque of the low turn capacity spring motor 250 into increased spool 20 rotations by providing a low: high ratio gearing. A reverse arrangement could involve the translation of a high spring turn capacity spring motor into increased torque applied to the spool shaft 32 by a gear assembly having a high:low gear ratio. For example, the gear mechanism 250 may be a multiplier having a 1 :2 ratio by providing a fifty teeth sprocket 282 driven by the spring motor 250 through a drive shaft 252 shown in Figure 7. The drive shaft 252 may rotate about a rotation axis 28 land may be speed controlled by the brake mechanism 270.

The large sprocket planetary gear 282 is meshed with a small twenty-five teeth sprocket 283 that is concentrically mounted to the hub shaft 32. Accordingly, the embodiment shown in Figure 6 that includes the brake mechanism 270 is adapted to accommodate a lower capacity spring drive mechanism 250 with regard to the number of spring rotationsj sacrificing torque for increased rotations through the gear assembly 280. Such a reel arrangement 210 is suitable for light gauge, but lengthy hose, where moderate torque, only, is required, and high spring rotations are a priority to accommodate hose of a long length. Of course, the gear ratios can be modified to achieve a different ratio by substituting the gear 282,283 components, or reversed to provide a reel assembly 210 with high torque applied to the hub shaft where the hose is of a heavy gauge, but of a relatively shorter length.

The reel frame includes an upstanding bracket 240 extending up from a frame base 246 to provide a vertical support structure on the spring cassette 250 side of the spool 20. The bracket 240 is equivalent to the frame structure 14 in Fig. 1 and provides a rigid structure to which the spring cassette 250 (and spring cassette 50 shown in Fig. 1) is rigidly mounted by cylindrical mounting blocks 244,245 that provide rigidity and spacing elements. The blocks 244,245 extend from, and are bolted to, the periphery of the spring cassette 250 drum to the bracket 240 where they are rigidly bolted thereto. Bolts may be replaced by any other suitable substitute fastening or welding attachment as will be appreciated by the person skilled in the art, but for ease of disassembly and retrofitting, bolt fasteners are preferred.

The plates 287a,b shown in Figs. 7 and 8 are mounted to each other by a set of pins and spaced apart by spacer sleeves 242,243 that permit some play between the gear assembly 280 component parts 287a,b, 242,243 of the order of 0.2—2 mm. The plates 287a,b have a slim profile and sandwich there between the planetary gears 282*283, which themselves are very slim in profile. The spacing of the plates 287a,b is comparatively narrow and preferably the outer width of the gear assembly 280 in profile is in the range of 10 mm - 30mm and more preferably 15 - 25 mm. This permits an extremely compact reel 210 that is also lightweight due to the use of a spring motor 250, rather than a motorised alternative. With specific reference to Figure 7, the brake assembly 270 and spring cassette 250 are not shown to give a clear view of the gear assembly housing 286. The gear housing 286 includes a pair of spaced parallel, substantially rectangular plates 287a,b lying in parallel planar relationship with the planetary gears 282, 283 mounted for rotation there-between.

Figure 8 shows the planetary gear arrangement more clearly, including the large sprocket 282 meshed with a small sprocket 283 in a 1 :2 ratio, whereby to multiply the spring 250 rotations of the drive shaft 252 by a factor of 2 for the hub shaft 32 directly turning the spool 20. Of course, a variety of other ratios are within the scope of this invention and this embodiment is merely exemplar of a range of ratios that may vary between 1 :4 and 4: 1, depending on the application.

In Figure 9, there is provided another alternative to the stacked cassette arrangement shown in Fig. 6. This stacked arrangement is a particularly preferred embodiment comprising a reel 320 on which are mounted a spring motor drum 350, a brake drum 370, and a planetary gear drum 380, all being identical in external appearance and all able to be added to each other in an additive or stacked arrangement onto the drive shaft 352, contiguous or continuous, and axially aligned, with the hose reel shaft. The cylindrical gear case 380 is preferably fashioned around or dimensioned identically to the spring motor case 350, and may be similarly mounted and stacked in the same way as the brake and spring motor system 250 shown in Fig. 6. However, in this case, the gear system in the cylindrical case or drum 380 is a planetary arrangement. This alternative integrates readily with the spring motor and brake add-on drums 350,370 and is particularly advantageous from a functional perspective, in that all main rotating parts are axially aligned, and from an aesthetic view point the axial alignment is more compact and easier to store.

Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directl references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.

In the present specification, terms such as "apparatus", "means"* "device" and "member" may refer to singular or plural items and are terms intended to refer to a set of properties, functions or characteristics performed by one or more items or components having one or more parts. It is envisaged that where an "apparatus", "means", "device" or "member" or similar term is described as being a unitary object, then a functionally equivalent object having multiple components is considered to fall within the scope of the term, and similarly, where an

"apparatus", "assembly", "means", "device" or "member" is described as having multiple components, a functionally equivalent but unitary object is also considered to fall within the scope of the term, unless the contrary is expressly Stated or the context requires otherwise.

Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be inteipreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the base lowermost. It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.