This application is a U.S. National Stage of International Patent Application No. PCT/AU2014/050009, filed Apr. 2, 2014, which in turn claims priority to Australian Patent Application No. 2013901171, filed Apr. 5, 2013, priority of which is also claimed herein. The entire content of the foregoing applications is incorporated herein by reference in its entirety.
The present invention relates to hand held portable appliances such as motorised blowers which have a motor or engine which induces vibration and which, in use, are held by a single hand of the operator. Such blowers have a fan axis of rotation which is substantially perpendicular to the plane in which the air is expelled.
It has long been known to provide such appliances with anti-vibration handles in which the handle is connected to the body of the appliance by means of coil spring connections. U.S. Pat. Nos. 4,819,742 and 5,361,500 and US Application No 2011/0226501 are indicative of this art as applied to chain saws. However, chain saws are operated two handed and thus represent a different class of handle.
Where the anti-vibration handle is intended to be grasped by one hand, the handle is generally cylindrical having a longitudinal axis which extends between two ends. Each end is connected to the body of the appliance by means of a corresponding spring. As a consequence, the handle is able to rotate in either direction through a small arc about its longitudinal axis as a result of the flexing of the springs. Particularly where the appliance produces reaction forces in its operation, this can result in undesirable, and unwanted, movement between the handle of the appliance and the body of the appliance. The consequence is that the operator does not have full control of the appliance and injuries or other damage may result.
Furthermore, many prior art blowers are awkward to operate. In particular, in those prior art blowers where the axis of the air outlet tube is not aligned with the axis of the handle, in use a torque is generated by the air exiting from the outlet tube with tends to rotate the blower about a vertical axis. This torque must be resisted by the wrist of the operator and this requires sustained muscular effort over time.
In addition, even if the axis of the air outlet tube is aligned with the handle of the blower, the outlet tube of the blower must be directed more downwardly in use than in its normal carrying position. As a consequence, the wrist of the operator must be cocked downwardly so as to place the hand in the correct angle to direct the blast of air towards the ground, and in this way blow leaf litter and other debris in the desired direction. Furthermore, the blast of air must normally be directed from left to right and back again in a swinging arcuate movement. Each of these requirements increases the fatigue of the operator.
The genesis of the present invention is a desire to provide an arrangement in which some, or all, of the above defects are overcome, or at least ameliorated.
In accordance with a first aspect of the present invention there is disclosed a method of operating a portable motorised blower in a stabilised equilibrium condition, said blower having a motor, a fan driven by the motor, an elongate air exit tube having an exit opening through which air from said fan is expelled, and a handle having a portion able to be grasped by a single hand of an operator, said portion having a longitudinal axis, said method comprising the steps of:
In accordance with a second aspect of the invention there is disclosed a method of operating a portable motorised blower in a stabilised equilibrium condition, said blower having a centre of gravity and a motor, a fan driven by the motor, an elongate air exit tube having an exit opening through which air from said fan is expelled, and an elongate handle having a handle longitudinal axis, said method comprising the steps of:
In accordance with a third aspect of the present invention there is disclosed a portable motorised blower having a centre of gravity, a motor, a fan driven by the motor, an elongate air exit tube having a tube exit opening through which air from said fan is expelled, and an elongate handle having a longitudinal axis; wherein the tube exit opening and the longitudinal axis of said handle are aligned, said handle is extended in a direction away from said tube to create two locations at each of which said handle can be grasped by an operator's single hand, said first location being substantially above said centre of gravity, and said second location being spaced from said first location in a direction away from said tube whereby with said single hand grasping said handle at said second location, the weight of the blower experienced by the operator is reduced by a thrust created by air being expelled from the tube exit opening.
In accordance with a still further aspect of the present invention there is disclosed an anti-vibration handle for a hand-held appliance having a motor or engine which induces vibration, and a body to which said the motor or engine is mounted; said handle comprising a first elongate portion and a second outrigger portion; said first elongate portion having two ends, having a generally longitudinal axis extending between said two ends, being shaped to be grasped by one hand of an operator between said ends; and said second outrigger portion being located adjacent one of said ends, extending generally perpendicularly to said longitudinal axis from said first elongate portion, terminating in a free end, and being firmly connected with said first elongate portion; said two ends and said free end each having a corresponding one of three coil springs by means of which said ends can be attached to the body of said appliance, and said outrigger portion being closely spaced from said body so as to not function as a graspable handle portion, whereby said outrigger portion restrains said first portion from rotating about its longitudinal axis due to flexing of the two springs connected to said two ends.
Preferably, the body includes a housing fabricated as two components and each said spring has a fastener with a captive head and which passes through one of said housing components, into the other of said housing components, and clamps said housing components together.
In accordance with yet another aspect of the present invention there is disclosed a blower having a fan driven by an internal combustion engine, at least one tube forming an air exit for said fan, and a generally L-shaped handle comprising a substantially U or C-shaped handle and an outrigger to said U or C-shaped handle, wherein said blower has an exterior body formed from two parts, one of said parts having a grille forming an air intake for said fan and a plurality of blind holes, the other of said parts having said internal combustion engine mounted thereon and having a plurality of through holes, and said L-shaped handle having a plurality of fasteners which each pass through a corresponding one of said through holes and into a corresponding one of said blind holes to clamp said other part between said one part and said L-shaped handle.
A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
As seen in
As seen in
The above-mentioned transport position is to be contrasted with the situation in use which is illustrated in
In the configuration illustrated in
Turning now to
It will be seen from
As best seen in
If the outrigger 26 were absent, the first portion 21 would be able to rotate about its longitudinal axis 24 as a result of flexing of the springs 32, 33. However, the presence of the firmly fixed outrigger 26 inhibits this rotation since the smallest rotational movement of the first portion 21 is magnified at the free end 27 of the outrigger 26 and counteracted by means of the spring 37. As a result, this rotation of the first portion 21 about its longitudinal axis 24 is practically eliminated.
As best seen in
As best seen in
It will be apparent that the part 51 is provided with three blind threaded holes 72, 73 and 77 (
In addition, the assembly of pieces making up the housing part 51 is provided with three blind holes 101, 102, and 103 which respectively receive three fasteners 111, 112, and 113 which pass through corresponding clearance holes 121, 122 and 123. The fasteners 111 and 112 retain the foot 61 and the fastener 113 assists in clamping the housing part assemblies 51 and 52 together.
A particular advantage of the above construction is that the assembled housing part 51 as seen in
Turning now to
As seen in
However, when the blower is operating, air is expelled from the tube 14. Particularly if the fan disclosed in Australian Patent Application No 2013 263 811 (to which U.S. patent application Ser. No. 14/095,154 corresponds) is installed within the housing 12, the volume of air which is expelled at high speed from the tube 14 is substantial and provides a significant thrust which tends to lift the blower 10. The exit 15 of the tube 14 is generally co-planar with the handle 16, even if the passage of the air from the fan to the tube exit 15 is curved so as to create a chicane as described in the abovementioned patent application. As a consequence of the above, and the alignment of the longitudinal axis 24 of the handle 16 and tube exit opening 15, the lift produced by the expelled air is generally in the plane of the handle 16.
In order to ease operator fatigue, the handle 16 has its first U or C-shaped portion 21 elongated in a direction away from the tube 14. As a consequence of this elongation, the operator can place the four fingers of the operating hand in the position illustrated by dashed lines in
That is, with the operator's hand grasping the first portion 21 of the handle 16 in the second location 66, the blower tends to rotate in a clockwise direction as seen in
The throttle lever 18 is elongated as best seen in
As seen in
However, in
From a comparison of
As illustrated in
During the abovementioned weighing procedure, with the hook 69 centrally located on the second location 66 in the position of the fingers illustrated in dashed lines in
In addition, there is an upwards force on the handle 16 generated by the thrust of the air expelled from the air exit 15. The result is a stable equilibrium condition of the forces acting on the blower 10 which means that there is no force, or torque, required to be counteracted by the operator which leads to reduced fatigue.
Furthermore, and most importantly, during use the weight of the blower 10 experienced by the operator as measured by the scale 70 is reduced because of the thrust generated by the air exiting from the tube 14. The weight recorded at sea level on the scale 70 with the blower 10 operating, is approximately 3.6 kg compared with a weight registered on the scale 70 of 4.6 kg if the blower 10 is not operating. This is a weight reduction of approximately 22%. The engine 11 was a four stroke engine in both instances. Alternatively, if the engine 11 is a two stroke engine, then the scale 70 records a weight of approximately 4.2-4.3 kg if the blower 10 is not operating and a weight of approximately 3.2-3.3 kg when the blower 10 is operating. The weight reduction of the blower 10 in use is dependent upon the height above sea level of the operator. The inventors have measured that at sea level the weight reduction of the blower 10 experienced by the operator as recorded by the scale 70 with the blower 10 operating is approximately 1.0 kg at sea level, is approximately 0.9 kg at approximately 1000 meters above sea level, and is approximately 0.8 kg at approximately 2000 meters above sea level. This change is brought about by the reduction in the density of the air exiting the tube 14 at higher elevations. The weight reduction also varies slightly at a given altitude upon variations in atmospheric pressure.
The foregoing describes only one embodiment of the present invention and modifications, obvious to those skilled in small engine appliance manufacturing, can be made thereto without departing from the scope of the present invention. For example, the dip angle of the single tube 14 of the blower 10 can be increased to approximately 30° because of the short length of the air exit tube 14 compared to the combined length of the two tubes 5,6 of the prior art devices.
The term “comprising” (and its grammatical variations) as used herein is used in the inclusive sense of “including” or “having” and not in the exclusive sense of “consisting only of”.
Number | Date | Country | Kind |
---|---|---|---|
2013901171 | Apr 2013 | AU | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/AU2014/050009 | 4/2/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2014/161048 | 10/9/2014 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3652074 | Frederickson | Mar 1972 | A |
3972119 | Bailey | Aug 1976 | A |
4325163 | Mattson | Apr 1982 | A |
4792286 | Gassen | Dec 1988 | A |
4819742 | Driggers | Apr 1989 | A |
5031273 | Yamaguchi | Jul 1991 | A |
5361500 | Naslund et al. | Nov 1994 | A |
5697456 | Radle | Dec 1997 | A |
6305909 | Jankowski et al. | Oct 2001 | B1 |
6799642 | Wolf | Oct 2004 | B2 |
7219433 | Gorenflo | May 2007 | B2 |
7270320 | Menzel | Sep 2007 | B2 |
7357380 | Menzel | Apr 2008 | B2 |
7412959 | Wolf | Aug 2008 | B2 |
7568682 | Seelmann | Aug 2009 | B2 |
8225514 | Guip | Jul 2012 | B2 |
9216517 | Kurzenberger | Dec 2015 | B2 |
9561599 | Kurzenberger | Feb 2017 | B2 |
9623547 | Kurzenberger | Apr 2017 | B2 |
20060179602 | Schliemann et al. | Aug 2006 | A1 |
20110226501 | Wolf et al. | Sep 2011 | A1 |
20140154106 | Notaras et al. | Jun 2014 | A1 |
Number | Date | Country |
---|---|---|
2423276 | Aug 2006 | GB |
Entry |
---|
International Search Report dated May 14, 2014 in International Patent Application No. PCT/AU2014/050009. |
Written Opinion dated May 14, 2014 in International Patent Application No. PCT/AU2014/050009. |
Number | Date | Country | |
---|---|---|---|
20160059402 A1 | Mar 2016 | US |