US20110113592A1

US20110113592A1 - Blower/vacuum tube attachment

Info

Publication number: US20110113592A1
Application number: US12/737,460
Authority: US
Inventors: Bret Robison
Original assignee: MTD Products Inc
Current assignee: MTD Products Inc
Priority date: 2008-07-31
Filing date: 2009-07-29
Publication date: 2011-05-19
Also published as: CA2731675A1; WO2010014214A1

Abstract

A blower/vacuum device has removable blower tube configured to connect with a connector stub of the device. The connector stub has a guide path formed in its interior wall and the blower tube has a latch runner disposed on its outer surface. A flipper is positioned in the guide path near the end of the circumferential segment of the guide path and coacts with the latch runner. The flipper is biased such that its tongue extends into the guide path. When the blower tube is rotated a sufficient distance such that the latch runner is rotated past the tongue, the flipper is repositioned by spring force and the tongue locks the blower tube in place. The flipper is repositioned to move the tongue out of contact with the latch runner to permit the blower tube to be rotated in the disconnect direction and removed from the connecting stub.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of U.S. Provisional Patent Application Ser. No. 61/137,530 filed Jul. 31, 2008.

BACKGROUND OF THE INVENTION

1. Field of Invention
This invention relates generally to the field of hand-held blower/vacuum or dedicated blower devices, and more particularly, to a mechanical connection between a blower tube and the housing of the device.
2. Description of Related Art
Portable hand-held leaf blowers have become popular outdoor maintenance products among residential and commercial landscapers, especially for spring and fall clean-up services. Blowers which can convert to vacuums provide an added degree of versatility to this product. A conventional leaf blower/vacuum device has a high speed impeller rotated by an output shaft of either an electric motor or an internal combustion engine. The impeller is enclosed within a scroll formed in the housing of the blower/vacuum device. The motor or engine is mounted to the housing or is sometimes enclosed within a separate housing. A handle enables the blower/vacuum device to be picked up and held with one hand and used to blow or vacuum leaves, grass clippings, and other debris.
The blower/vacuum device can be converted for use as either a blower or a vacuum by attaching an elongated tube to either the inlet or the outlet of the impeller housing. In a blower mode, the tube concentrates air expelled through the air outlet to create a highly-directed stream of high velocity air at the end of the tube. A cover is placed over the air inlet for preventing accidental ingestion of objects while permitting a free flow of air into the air inlet. In a vacuum mode, the blower tube is removed from the outlet. A vacuum tube, typically having a larger diameter than the blower tube, is attached to the air inlet after the cover is removed. Air drawn through an opening in the end of the vacuum tube tends to entrain leaves and other debris in the vicinity of the end of the vacuum tube. The leaves are carried by the flow into the fan and then discharged into a porous collector sack attached to the outlet.
During operation or storage of the blower/vacuum device, contact of the free end of the tube with the ground can occur and cause the tube to become displaced from its normal operating position. This can lead to an unintended loosening of the tube or even cause the tube to drop off. In this way, operation of the device is negatively affected. Additionally, operation of the blower/vacuum device without the tube in place can be dangerous, as removal of the tube exposes the rotating impeller to the operator. It is therefore desirable to have an improved connection between the tube and the housing that requires dedicated action on the part of the user to remove the tube from the housing.

SUMMARY OF INVENTIVE FEATURES

One embodiment of the invention is directed to a blower/vacuum device. The blower/vacuum device has a housing formed of two component shells forming a spiral blower scroll. The housing defines an air inlet for guiding air into the spiral blower scroll and an air outlet which directs air out from the spiral blower scroll, the air outlet being formed in generally tangential the spiral blower scroll. A connector stub is formed in the housing at the air outlet. The connector stub has a guide path formed in the interior wall thereof. The blower/vacuum also has a removable blower tube configured to connect with the connector stub such the longitudinal center axis of the blower tube aligns with the longitudinal center axis of the connector stub. The blower tube has a latch runner disposed on the outer surface thereof. The guide path is open at an insertion point at an end of the connecting stub such that it is configured to receive the latch runner upon insertion of the blower tube into the connector stub. The guide path includes a first axial segment extending approximately parallel to the longitudinal center axis of the connector stub, a circumferential segment essentially at a right angle to the axial segment, and an arc-shaped transition segment connecting the axial segment with the circumferential segment. When the blower tube is inserted into the connecting stub, the blower tube is compelled to make a rotational movement because of the arc-shaped form of the transition segment.
The improvement is a mechanical connection between the connector stub and the blower tube, wherein the mechanical connection includes the latch runner disposed on the outer surface of the blower tube, a flipper positioned in the guide path near the end of the circumferential segment of the guide path 34 that coacts with the latch runner, and a spring that biases the flipper such that a tongue of the flipper extends into the opening of the connector stub. The flipper is rotatably captured between the two component shells of the housing. The latch runner has a ramped leading wall and a rear wall substantially perpendicular to the surface of the blower tube. The ramped leading wall allows the latch runner to proceed along the circumferential segment of the guide path when installing the blower tube and push the tongue of the flipper out of the way of the latch runner against the biasing force of the spring as the blower tube is rotated. When the blower tube is rotated a sufficient distance such that the latch runner is rotated past the tongue, the flipper is repositioned by force of the spring and the tongue and moves behind the rear wall of the latch runner to lock the blower tube in place such that when the blower tube is rotated in a reverse direction, the tongue of the flipper catches on the perpendicular rear wall of the latch runner, thereby preventing the blower tube from rotating in the reverse direction and being removed from the connector stub. The flipper can be repositioned by the user to move the tongue out of contact with the perpendicular rear wall of the latch runner to permit the blower tube to be rotated in the reverse direction and removed from the connecting stub. The flipper is positioned such that access to the flipper is obtainable through a window formed in the surface of the housing such that a tool may be inserted through the window and into a slot in the flipper to rotate the flipper.
These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure, operation, and advantages of the presently disclosed embodiment of the invention will become apparent when consideration of the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a partially exploded perspective view of a portion of a handheld blower/vacuum device with a blower tube mountable on a connector stub of the device according to the invention;

FIG. 2 is an enlarged exploded view of the connector stub and blower tube of FIG. 1; and

FIG. 3 is cutaway view of the blower vacuum device of FIG. 1 showing the mechanical connection between the blower tube and the connector stub.

Corresponding reference characters indicate corresponding parts throughout the views of the drawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The invention will now be described in the following detailed description with reference to the drawings, wherein preferred embodiments are described in detail to enable practice of the invention. Although the invention is described with reference to these specific preferred embodiments, it will be understood that the invention is not limited to these preferred embodiments. But to the contrary, the invention includes numerous alternatives, modifications and equivalents as will become apparent from consideration of the following detailed description.
Referring now to the drawings, FIGS. land 2 show a blower/vacuum device 10 having a housing 12 that forms a spiral blower scroll 14. As is known, an impeller (not shown) is rotatably driven in the spiral blower scroll 14 by a power source (not shown) such as an electric motor or internal combustion engine that is mounted in the housing 12. The housing 12 is desirably assembled of two component shells 12A, 12B, which in one embodiment are assembled via screws 16 by means of connection domes or fittings 16A that are disposed on the rims of the component shells 12A, 12B. A handle 18 is provided on the housing 12 for use by the operator in manipulating the blower/vacuum device 10.
Formed in the housing 12 is an air inlet 20 for guiding air into the spiral scroll 14, and an air outlet 22 that directs air out from the spiral blower scroll 14. The air outlet 22 is formed in the housing 12 approximately tangential the spiral blower scroll 14. A connector stub 24 is formed in the housing 12 at the air outlet 22 and a removable blower tube 26 is joined with the connector stub 24 such the longitudinal center axis of the blower tube 26 aligns with the longitudinal center axis of the connector stub 24. As best illustrated in FIG. 2, an overlap region 28 is provided between the blower tube 26 and the connector stub 24. An assembly end 29 of the blower tube 26 is inserted into the generally tubular connecting stub 24 and secured in the connector stub 24 by means of a mechanical connection 30 located near the assembly end 29 in the overlap region 28.
According to the invention, the mechanical connection 30 comprises at least one latch runner 32, broadly a projection, disposed on an outer surface 33 of the blower tube 26. In one embodiment, two latch runners or projections 32 are provided in the overlap region 28 and lie desirably diametrically opposite each other with respect to the longitudinal center axis of the blower tube 26. As best seen in FIG. 1, a guide path or track 34 is formed as a channel in the interior wall 36 of the connector stub 24 and has a generally U-shaped cross-sectional configuration. At least one guide path 34 is provided for each of the latch runners 32 on the blower tube 26. The open channel of the guide path 34 faces the interior of the connector stub 24.
In the illustrated embodiment, each guide path 34 includes a first axial segment 34A extending approximately parallel to the longitudinal center axis of the connector stub 24. The guide path 34 is open at its insertion point 37 at the outer end of the connecting stub 24 such that the guide path 34 is configured to receive the latch runner 32 upon insertion of the blower tube 26 into the connector stub 24. From its axial segment 34A, the guide path 34 extends via a transition segment 34B into a circumferential segment 34C. Each transition segment 34B is shaped so as to correspond generally to a quarter circle such that the circumferential segment 34C is oriented substantially perpendicular with the axial segment 34A.
To mount the blower tube 26, the assembly end 29 of the blower tube 26 is inserted into the connecting stub 24 and travel of the latch runner 32 in the guide path 34 permits the operator to insert and rotate the tube to its operational position. When the latch runner 32 enters into the transition segment 34B, the user is compelled to rotate the blower tube 26 because of the arc-shaped form of the transition segment 34B. To complete assembly of the blower tube 26, the user must rotate the blower tube 26 in the assembly rotational direction (clockwise direction in the illustrated embodiment) until the mechanical connection 30 latches as will be described below. In the illustrated embodiment, an end 34D in the circumferential segment 34C lies offset by approximately 90 rotational degrees from the open insertion point 37 of the axial segments 34A such that the blower tube 26 is rotated a quarter of a turn in the assembly rotational direction with respect to the connector stub 24 during the insertion process. However, one skilled in the art will understand that the degree of rotation can be more or less than 90 degrees without departing from the scope of the invention.
As best seen in FIG. 2, the mechanical connection 30 is formed with a tongue 40 extending from a flipper 42 positioned near the end 34D of the circumferential segment 34C of the guide path 34 that coacts with the latch runner 32. The tongue 40 of the flipper 42 extends from a body portion 44 that is rotatably captured in the connecting stub 24 between the two component shells 12A, 12B of the housing 12. A spring 46 normally biases the flipper 42 such that the tongue 40 extends generally in the radial direction into the connecting stub 24 (in the clockwise direction as viewed in FIG. 3). It is to be understood that the invention is not limited to any particular embodiment or method of fabrication of the housing and mechanical connection. Accordingly, terms such as “clockwise” and “counter-clockwise” and “upper” and “lower” are used to aid in describing the illustrated embodiment with reference to the drawings and should not be interpreted as limiting. The flipper 42 is spring biased in the clockwise direction, thereby engaging the latch runner 32 to “lock” the blower tube 26 in its operational position as will be discussed below.
The latch runner 32 is desirably configured so as to have a generally rectangular cross section with a ramp 50 which leads when rotating the blower tube 26 in the assembly rotational direction. The ramp 50 has a slope angle of preferably between 25 to 65 degrees. The rear wall 52 of the latch runner 32 is configured to extend substantially perpendicular from the surface 33 of the blower tube 26. The ramp 50 is provided to allow the latch runner 32 to proceed along the circumferential segment 34C of the guide path 34 when installing the blower tube 26 and push the tongue 40 of the flipper 42 out of the way of the latch runner 32 against the biasing force of the spring 46 as the blower tube 26 is assembled with the connector stub 24. When the blower tube 26 is rotated a sufficient distance such that the latch runner 32 is rotated past the tongue 40, the flipper 42 rotates clockwise by force of the spring 46 and the tongue 40 moves behind the rear wall 52 of the latch runner 32 to lock the blower tube 26 in its operational position. When the blower tube 26 is rotated counter-clockwise, the tongue 40 of the flipper 42 catches on the perpendicular rear wall 52 of the latch runner 32, thereby preventing the blower tube 26 from being removed from the connector stub 24. In order to remove the blower tube 26 from the connector stub 24, the flipper 42 must first be rotated counter-clockwise to move the tongue 40 out of contact with the perpendicular rear wall 52 of the latch runner 32. Once the flipper 42 is rotated, the blower tube 26 can be rotated counter-clockwise and removed from the connecting stub 24.
As best seen in FIGS. 1 and 2, the body portion 44 of the flipper 42 is accessible through a window 60 formed in the surface of the housing 12. Desirably, a tool, such as a screwdriver, must be inserted through the window 60 and into a slot 62 in the end of the flipper body 44 in order to apply an external force to the flipper 42 and rotate the flipper 42. However, it is conceivable that the flipper 42 may be configured such that the external force used to rotate the flipper 42 may be applied by the user's finger such that a tool is not required. Accordingly, the mechanical connection 30 prevents an unintended loosening of the blower tube 26 while simultaneously requiring the operator to undertake positive action in order to remove the blower tube 26.
While this invention has been described in conjunction with the specific embodiments described above, it is evident that many alternatives, combinations, modifications and variations are apparent to those skilled in the art. Accordingly, the preferred embodiments of this invention, as set forth above are intended to be illustrative only, and not in a limiting sense. Various changes can be made without departing from the spirit and scope of this invention.

Claims

1. A blower/vacuum device having a removable blower tube connected so as to prevent unintentional removal of the blower tube from the device, said device comprising:

a housing having a tubular connector stub at an air outlet of the housing, wherein at least one guide path is formed in an interior wall of said connector stub, the guide path having an insertion point at a proximal end of guide path located in an outward end of the connecting stub, an axial section leading from said insertion point, and a circumferential section leading from said axial section;

a removable blower tube configured to connect with the connector stub, the blower tube having a latch runner disposed on an outer surface thereof that is received in the guide path upon insertion of the blower tube onto the connector stub, the latch runner having a sloped leading edge and a trailing edge that extends substantially perpendicular from the outer surface of the blower tube, wherein said blower tube is compelled to rotate with respect to the connector stub as said latch runner travels along the circumferential section of the guide path;

a rotatable flipper located near a distal end of the guide path having a tongue configured to coact with the latch runner, the flipper having a locking position in which the tongue extends inward into the guide path and abuts the trailing edge of the latch runner when the blower tube is in an installed position, wherein said flipper is rotatably captured by the housing and is accessible through a window formed in said housing such that the an external force may be applied to said flipper; and

a spring acting upon the flipper, wherein said spring biases the flipper into its locking position;

wherein during installation of the blower tube, as the latch runner progresses along the circumferential section of the guide path, the sloped leading edge of the latch runner contacts the tongue and causes the flipper to rotate against the biasing force of the spring, thereby pushing the tongue out of the way of the latch runner, and when the blower tube is rotated into its installed position such that the latch runner moves past the tongue, the spring repositions the flipper into its locking position so that the tongue moves behind the trailing edge of the latch runner to lock the blower tube in place thereby preventing the blower tube from rotating in a disconnect direction and being removed from the connector stub, and during disconnect of the blower tube, the flipper is rotated by the user via application of an external force on the flipper against the biasing force of the spring to move the tongue out of contact with the trailing edge of the latch runner thereby permitting the blower tube to be rotated in the disconnect direction and removed from the connecting stub.

2. The device of claim 1 wherein the housing is formed of two component shells, wherein the flipper is rotatably captured between the two component shells of the housing.

3. The device of claim 1 wherein the flipper is located near the end of the circumferential segment of the guide path

4. The device of claim 1 wherein the flipper has a slot in one end thereof exposed by the window, wherein said slot is configured to receive a tool inserted though the window to rotate the flipper.

5. The device of claim 1 wherein when the blower tube is rotated in a disconnect direction and an external force is not acting upon the flipper to rotate the flipper, the tongue catches the perpendicular rear edge of the latch runner and prevents rotation of the blower tube in the disconnect direction.

6. The device of claim 1 wherein the axial segment of the guide path extends parallel with the longitudinal center axis of the connector stub and the circumferential segment is oriented substantially perpendicular to the axial segment.

7. The device of claim 1 wherein the guide path formed in the interior wall of said connector stub has a substantially U-shaped cross section.