Patent Publication Number: US-8984713-B2

Title: Portable blower with wear resistant discharge end

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to portable fluid blowers and, more particularly, to blowers that have a discharge end that can be controllably positioned by a user. 
     2. Background Art 
     Portable blowers have been used, particularly in the landscaping area, for decades. Common to these designs is the ability of a user to control placement of the fluid discharge end so as to select both discharge flow direction and location. 
     The portable configurations vary widely. As one example, a portable blower may be configured as shown in FIG. 1 of U.S. Pat. No. 5,926,910, wherein a housing containing the propulsion components is directly held by a user. A discharge conduit is in fixed relationship to the housing so that the user is required to reorient the entire apparatus as a unit to control air discharge. 
     In an alternative form, as shown in FIG. 7 of U.S. Pat. No. 6,077,033, a flexible conduit is provided to communicate air from a propulsion unit to an opening at the discharge end of a nozzle. The user exploits the flexibility of the conduit to control direction and location of the air discharge. 
     Common to virtually all designs is the provision of a nozzle with a discharge opening and a rim that extends around the opening and bounds a shape and area determinative of discharge volume and flow velocity. These units are commonly designed with the capacity of the propulsion unit matched to the conduit and discharge opening to generate air flow volume and velocity that are considered to be optimal. So long as the discharge opening, as determined by the rim shape, remains constant in configuration, the unit will have consistent operating characteristics. 
     Commonly, the rim defining the discharge opening area is integral with a length of conduit or a nozzle fitting attached appropriately to a conduit. Most commonly, the conduits and all associated fittings communicating air between the propulsion unit and the discharge opening, including the rim at the discharge end, are made from plastic material. This material selection is made primarily for weight minimization, particularly since most units are designed to be held by a user in an elevated position during use. Available plastics also generally have good durability. 
     However, a typical blower used by a landscaping crew may, over an extended period, experience significant wear. One area of concern is with the rim at the discharge end of the conduit or nozzle fitting. The exposed region of the rim may be repeatedly impacted against hard surfaces or dragged on those surfaces, as a result of which there may be progressive wear that changes the configuration of the rim and thereby potentially the effective area and/or shape of the discharge opening that it bounds. Whereas, when new, the capacity of the propulsion unit and the area and shape of the discharge opening are closely matched to optimize performance, over time this relationship may be altered as a result of which air discharge patterns, velocity, and/or volume may be detrimentally affected. 
     For the most part, changes in operating characteristics attributable to a reconfiguration of the rim at the discharge end of the conduit or nozzle fitting, due to wear, may be gradual. As a result, the user may not even detect any performance compromise and may eventually attribute less than optimal performance to the original unit design. This may reflect poorly on the manufacturer when, in fact, the compromised performance due to regular anticipated wear may be inevitable with all of these types of blowers. 
     As a practical matter, those using blowers of this type on a daily basis are unlikely to be monitoring the condition of the rim at the discharge end. Even if regular monitoring is undertaken, replacement of part or all of the assembly communicating between the propulsion unit and the discharge end may be an inconvenience and represent a significant expense. This is aggravated by the fact that the rim at the discharge end may often be integrated with other conduit and fitting components so that the replacement part(s) may be somewhat expensive. 
     The reality is that users of portable blowers, particularly in the landscape industry, are not likely to regularly maintain the air communication components between the propulsion unit and the discharge end. Rather, they eventually contend with compromised unit performance which may translate into additional time needed to perform routine landscaping tasks or performance of tasks in an ineffective manner. 
     The industry continues to seek out improvements in this type of equipment that will contribute to greater product life without significantly increasing either the weight or cost of such equipment. 
     SUMMARY OF THE INVENTION 
     In one form, the invention is directed to a portable blower including a propulsion unit for continuously generating a supply of pressurized fluid and a conduit assembly for controllably directing fluid from the propulsion unit to and through a discharge opening on the conduit assembly. The discharge opening is bounded by a rim. The rim is defined at least partially by a discrete component made from a first material. The conduit assembly has a first portion made from a second material to which the discrete component is operatively connected. The first material is at least one of: a) more resistant to abrasive wear than the second material; b) more resistant to impact than the second material; and c) harder than the second material. 
     In one form, the discrete component is in the form of a ring. 
     In one form, the ring has a central axis, a diameter, and an axial length and the diameter is greater than the axial length of the ring. 
     In one form, air moving through the discharge opening moves in a first line. The first portion of the conduit assembly defines a first edge on the rim facing in one direction generally parallel to the first line. The discrete component defines a second edge that abuts to the first edge with the discrete component operatively connected. 
     In one form, the ring has a third edge facing generally in the one direction and engages the first portion of the conduit assembly so that a part of the first portion of the conduit assembly is captively held between the second and third edges to thereby maintain the discrete component operatively connected. 
     In one form, the ring has another edge that is substantially the same as the third edge and another part of the first portion of the conduit assembly is captively held between the second and another edges that in conjunction with the second and third edges maintain the discrete component operatively connected. 
     In one form, the ring is configured so that the ring can be translated from a separated, preassembly position relative to the first portion of the conduit assembly into an assembled position as an incident of which the discrete component is placed in the operative state and the part of the first portion of the conduit assembly becomes captively held between the second and third edges. 
     In one form, the third edge is defined by a first cantilevered tab. 
     In one form, the third edge is configured to define spaced contact regions that each digs into the first portion of the conduit assembly. 
     In one form, at least one of the contact regions is defined at the apex of a “V” shape on the first cantilevered tab. 
     In one form, the first cantilevered tab has a perimeter edge that is in the shape of a “W” that defines the spaced contact regions. 
     In one form, the ring has an annular wall that extends around the first portion of the conduit assembly and the first cantilevered tab is formed by being struck from the annular wall. 
     In one form, the first portion of the conduit assembly is made from a non-metal material and the ring is made from a metal material. 
     In one form, the first portion of the conduit is made from high density polyethylene and the ring is made from steel. 
     In one form, the ring has at least two cantilevered tabs in addition to the first cantilevered tab that are configured the same, and function the same, as the first cantilevered tab. 
     In one form, the ring is made from material having a gauge on the order of 22. 
     In one form, the ring has an outside diameter of 2.5 to 3.5 inches. 
     In one form, air moving through the discharge opening moves in a first line, and the ring extends fully around the discharge opening and has transverse surface portions each extending continuously around the discharge opening. 
     In one form, the first portion of the conduit assembly defines an annular corner on the rim extending fully around the discharge opening and the ring overlies the annular corner. 
     In one form, the portable blower has a weight and size that allow the portable blower to be held and operated by a user in an elevated position. The conduit assembly is one of: a) configured so that the discharge opening is substantially fixed relative to the fluid propulsion unit whereby a user is required to reorient the portable blower to reposition the discharge opening relative to a surface against which fluid is to be propelled; and b) configured so that a user can selectively reposition the discharge opening relative to the fluid propulsion unit to reposition the discharge opening relative to a surface against which fluid is to be propelled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic representation of a portable blower incorporating at least one discrete wear component according to the present invention; 
         FIG. 2  is a partially schematic, perspective view of a specific form of portable blower, suitable for incorporation of the invention, without the at least one discrete component thereon; 
         FIG. 3  is an enlarged, elevation view of a conduit assembly on the portable blower in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of the conduit assembly taken along line  4 - 4  of  FIG. 3 ; 
         FIG. 5  is an enlarged, end elevation view of the conduit assembly in  FIGS. 3 and 4 ; 
         FIG. 6  is a view as in  FIG. 3  wherein a portion of the conduit assembly at a discharge end thereof has been worn away, as through use; 
         FIG. 7  is a partially schematic, perspective view of the portable blower in  FIG. 2  from a different perspective and with a discrete component according to the invention and, in the form of a ring, operatively connected at a rim on the conduit assembly thereon; 
         FIG. 8  is an enlarged, perspective view of the ring operatively connected to the portable blower in  FIG. 7 ; 
         FIG. 9  is an enlarged, end view of the ring in  FIGS. 7 and 8 ; 
         FIG. 10  is an enlarged, fragmentary, elevation view of the discharge end of the conduit assembly on the blower unit in  FIG. 7  with the ring in a spaced, preassembly position relative thereto; 
         FIG. 11  is an enlarged, fragmentary, cross-sectional view showing part of the ring with a tab thereon being advanced from the  FIG. 10  position towards an assembled position; 
         FIG. 12  is a view as in  FIG. 11  with the ring advanced fully to the assembled position so that it is operatively connected; 
         FIG. 13  is an enlarged, cross-sectional view of the discharge end of the conduit assembly with the ring operatively connected; 
         FIG. 14  is an enlarged, fragmentary, perspective view of one of the tabs on the ring interacting with a first portion of the conduit assembly with the ring operatively connected; 
         FIG. 15  is an enlarged, perspective view of the discharge end of the conduit assembly with the ring operatively connected; 
         FIG. 16  is an end elevation view of a modified form of ring, according to the invention, operatively connected to a portion of a conduit assembly; and 
         FIG. 17  is a cross-sectional view of a further modified form of ring, according to the invention and operatively connected to a conduit assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In  FIG. 1 , a portable blower is shown at  10  incorporating the present invention. The schematic showing is intended to encompass blowers with virtually an unlimited number of different configurations. Common to each of these configurations is a propulsion unit  12  that continuously generates a supply of pressurized fluid—typically air—and a conduit assembly  14  for controllably directing fluid from the fluid propulsion unit  12  to and through a discharge opening  16  at a discharge end of the conduit assembly  14 . The discharge opening  16  is bounded by a rim  18 . According to the invention, the rim  18  is defined at least partially by at least one discrete component  20  made from a first material. The conduit assembly  14  has a first portion made from a second material to which the discrete component  20  is operatively connected. The first material is at least one of: a) more resistant to abrasive wear than the second material; b) more resistant to impact than the second material; and c) harder than the second material. 
     The schematic depiction of the portable blower  10  is intended to encompass specific configurations disclosed herein, other existing portable blower configurations, and those that might be devised to function as intended herein. Exemplary portable blowers are shown in U.S. Pat. Nos. 5,926,910 and 6,077,033. 
     In U.S. Pat. No. 5,926,910, the portable blower has a weight and size that allow it to be held in one hand of a user and operated by the user in an elevated position. The conduit assembly thereon is configured so that the discharge opening is substantially fixed relative to the fluid propulsion unit so that a user is required to reorient all components of the portable blower as a unit to reposition the discharge opening relative to a surface against which fluid is to be propelled. 
     In U.S. Pat. No. 6,077,033, the conduit assembly is configured so that a user can selectively reposition the discharge opening relative to the fluid propulsion unit and a surface against which fluid is to be propelled. 
     One specific form of portable blower  10  is the Assignee&#39;s own construction, as shown at  10  in  FIGS. 2-6 . The portable blower  10  consists of the aforementioned fluid propulsion unit  12 , of a design specifically for air movement. The unit  12  has a housing  22  carried upon a manipulable support  24  that may be in the form of an elongate housing. A suitable drive  26  for the propulsion unit  12  is carried on the support  24  and is operable to cause the propulsion unit  12  to continuously generate pressurized air that is directed through the conduit assembly  14  that is in the form of a nozzle with a fixed configuration, secured to the housing  22 . The conduit assembly  14  has an annular wall  30  that tapers progressively from an upstream end  32  to a downstream/discharge end  33  with the discharge opening  16  thereat that is shown to be circular in cross-section. The discharge opening  16  might have shapes other than circular, as well known to those in this art. The pressurized air is discharged in a first line, as indicated by the arrow  34 , that is parallel to the central axis  36  of the conduit assembly  14 . 
     In operation, the user will reposition the entire blower  10  to situate the discharge end  33 , and discharge opening  16  thereat, at the desired location, with the blower  10  oriented selectively to additionally pick the optimal relationship of the flow direction to the surface against which the air is to be propelled, as to reposition loose matter thereon. 
     Typically, the rim  18  bounding the discharge opening  16  has exposed leading and peripheral surfaces LS, PS, respectively, that are guided against, or repetitively contact, surfaces against which fluid is propelled during operation of the blower  10 . 
     As shown in  FIG. 6 , eventually, portions of the rim  18 , as indicated at X, may wear so that the discharge opening  16  has a different effective shape or area, with the latter generally larger than its initial area. As a result, the propulsion unit  12 , designed to deliver pressurized air at a volume and speed optimally matched to the original shape and area of the discharge opening  16 , is eventually directing air through a discharge opening  16  with larger area and/or different shape, as seen in  FIG. 6 . This may significantly change the operating characteristics for the portable blower  10 . 
     To avoid this condition, the at least one discrete component  20  is incorporated into the portable blower  10 , as shown in  FIGS. 7-15 . The discrete component  20  is in the form of a ring that is operatively connected to the aforementioned first portion  38  of the conduit assembly  14  at the rim  18 . The ring  20  overlies the rim  18  to protect the same. The rim  18 , as described and claimed herein, is considered to be that portion of the conduit assembly  14  that bounds the discharge opening  16  and includes a peripheral annular portion  40 , surrounding the discharge opening  16  over a short axial extent, and an annular extremity  42  with an exposed surface/first edge  43  that faces axially of the conduit assembly  14 . The rim  18  also includes the operatively connected ring  20 . 
     With the ring  20  operatively connected, a peripheral wall  44  thereon surrounds an exposed outer surface portion  45  on the rim  18 , with a second edge  46  on a wall  47  extending radially inwardly from the wall  44  and overlying the surface  43  on the extremity  42 . Through this arrangement, the exposed ring  20  wraps around a corner at which the surface portion  45  and surface  43  meet and thereby overlies and shields the rim  18  to prevent any direct exposure of the surface portion  45  or surface  43  to a surface which the discharge end  33  of the conduit assembly  14  might otherwise contact during use. Optionally, the wall  47  might be eliminated; however, the edge  46  thereon is desirable for purposes of facilitating assembly, as explained hereinbelow. 
     The ring  20  is designed to be press fit by being translated relative to the first portion  38  of the conduit assembly  14  from a separated, preassembly position, as shown in  FIG. 10 , into an assembled position, as shown in  FIG. 13 , as an incident of which the ring  20  becomes operatively connected and maintained in that state. 
     With the ring  20  operatively connected, the first edge  43  abuts to the second edge  46  on the ring  20 . The first and second edges  43 , 46  are annular and face oppositely to abut so as to maintain the operatively connected ring  20  in the same axial position relative to the conduit assembly  14 . 
     At least one, and in the depicted embodiment eight, cantilevered tabs  50  are formed on the ring  20 . Each of the tabs  50  has the same construction and defines a third edge  52  that engages the first portion  38  of the conduit assembly  14  so that a part of the first portion  38  of the conduit assembly  14  is captively held between the second and third edges  46 ,  52 , thereby to maintain the ring  20  operatively connected. 
     Each of the tabs  50  is struck directly from the peripheral wall  44  and is bent radially inwardly at an edge  54 . The third edge  52  is part of a perimeter edge  56  that is in the shape of a “W”. The third edge  52  is configured to define spaced contact regions  58 ,  60  at the apices of separate “V” shapes on the tabs  50 . 
     The contact regions  58 ,  60  are configured to dig into the first portion  38  of the conduit assembly  14 , as seen particularly in  FIGS. 12 and 14 , with the latter showing discrete depressions D in the first portion  38 . This “digging” is somewhat exaggerated in  FIGS. 12 and 14  for purposes of clarity. 
     With the ring  20  in its separated position, as shown in  FIG. 10 , and concentric with the axis  36 , the ring  20  can be translated towards the assembled position of  FIG. 13  in a direction as indicated by the arrow  62 . As seen in  FIGS. 10 and 11 , the outside corner  64  of the first portion  38  of the conduit assembly  14  encounters each tab  50  and progressively bends the tabs  50  radially outwardly. Residual forces in each bent tab  50  cause it to be urged radially inwardly towards the outer surface  66  of the first portion  38  of the conduit assembly  14 . This force causes the relatively sharp contact regions  58 ,  60  to dig into the outer surface  66 , thereby precluding subsequent reverse axial movement of the ring  20  that might allow its separation. Once the ring  20  is fully in its operative position with the edges  42 ,  46  in abutment, a part of the first portion  38  of the conduit assembly  14  becomes captive between the third edge  52  on each tab  50  and the annular second edge  46 . 
     With the ring  20  operatively connected, the ring  20  defines an exposed annular corner  68  that nominally conforms to and overlies an annular corner  64  on the conduit assembly  14 . 
     While the ring  20  can be assembled and perform the shielding function with an axial extent greater than shown, all that is necessary for the ring  20  to perform its intended function is to have sufficient axial extent to form the tabs  50 , as described. As seen in  FIGS. 9 and 13 , the diameter D 1  of the ring  20  is substantially greater than the axial length L thereof. 
     Typically, the main components of the conduit assembly  14  are made from a lightweight material that has good durability. For this purpose, non-metal materials are desired, such as high density polyethylene. 
     The ring  20  is preferably made from a metal material, such as steel. The metal material may have a gauge on the order of 22. 
     In one exemplary form, the outer diameter D 1  of the ring is from 2.5 to 3.5 inches. However, this is a limitation that is very design specific, as the diameter could be virtually any size, including diameters substantially less than or greater than those within the above-noted range. 
     While the ring configuration is shown with exposed transverse portions  72 ,  74 , respectively, on the wall  44  and edge  46 , this precise relationship is not required. 
     Further, as shown in  FIG. 16 , it is not required that the ring extend fully around its central axis. A modified form of ring  20 ′ extends only partially around the corresponding axis  36 ′. 
     As a further alternative configuration, as shown in  FIG. 17 , a ring  20 ″ may be embedded in other components on the rim  18 ″ on the conduit assembly  14 ″. In this embodiment, the ring  20 ″ is exposed directly only at its axial edge  76 . Thus, if the overlying portion  78  is eventually worn away, the ring  20 ″ on the rim  18 ″ will become exposed and maintain the original shape and area of the discharge opening  16 ″. 
     The foregoing disclosure of specific embodiments is intended to be illustrative of the broad concepts comprehended by the invention.