Patent Application
20110131815
The present invention relates generally to lawn care equipment, and more particularly, relating to a combination blower and trimmer assembly for using in cutting vegetation and clearing areas from debris where the blower and trimmer portions are independently and separately operable.
Complete lawn care now typically includes trimming areas that lawn mowers cannot access easily; edging vegetation along defined perimeters, such as curbs; and removing the vegetation debris, such as lawn trimmings or fallen leaves, from areas where they are not wanted, such as sidewalks and driveways, typically by blowing them away to an area where they will not be seen, such as the lawn. Carrying out these separate tasks has traditionally required different and separate tools, namely, a lawn mower, a string trimmer, an edger and a blower.
In commercial applications particularly, such as grooming golf courses, the necessity for using different and separate tools for these tasks leads to lost time and inefficiency because workers must return to a tool shed or truck, often located at some distance from the workers, to retrieve the appropriate tool. A worker may carry and use a particular tool, for example, a string trimmer, for several hours without pause, leading him far from his tool shed or truck. The worker cannot carry all these different tools with him due to their bulk and weight.
Combining the functionality of some of these separate tools into a single tool would save time and money, including capital outlay for the tools.
Some efforts in that direction have been taken. For example, a device includes separate operating heads, such as a string trimmer head or a blower head, that can be attached and detached from the same power plant and drive train, saving the expense of a second motor. This system still requires that a significant subassembly of the tool be removed and replaced by another tool, requiring the worker to carry separate tools and to change operating heads on the tool. This system has the same disadvantages as having separate tools when they are used.
Another device includes a blower chute that can be strapped onto the bottom of a string trimmer with a bungee cord, but does not allow the string trimmer function to be used when the blower attachment is installed, requiring the operator to carry separate subsystems and install and remove them to carry out the separate functions of trimming and blowing.
Another device discloses a string trimmer with a specially designed shroud that is supposed to help the rotating string of the string trimmer to function as a blower. While it has long been known that the rotating string of the string trimmer provides some blowing forces, they tend to be non-directional and basically downward and outward from the rotating string, which provides little benefit in debris removal from sidewalks and so forth. Further, any blowing force generated by the rotating string is minimal and will not move debris any significant distance.
Another device discloses a string trimmer that can be converted to a blade trimmer and that can be modified to attach a blower flute or scroll to direct air flow generated by a cooling fin that is part of the string trimmer spool and designed to cool the motor of the apparatus. The use of this fan in a attempt to create a blower function is inadequate because it utilizes a fan that is designed only for motor cooling and is structurally a part of a string trimmer head, limiting its utility for actually blowing debris, due to its position and its use to cool the motor. A string trimmer head that does not include a cooling fan could apparently not be used with this device.
Another device discloses a string trimmer and blower combination that includes a separate blower assembly and trimmer assembly. The blower assembly includes an air inlet and an air inlet cover that is positionable to close the air inlet, and thus prevent the blower from discharging an appreciable air flow. The idea is to close the air inlet when it is not desirable to use the blower function to starve the blower impeller of intake air. The trimmer head can be removed when it is desirable to use the blower. Closing off the air inlet to the blower while the blower impeller is driven is not desirable as it would result in heat build-up and likely failure of the blower. Further, this device requires the engine or motor to be turned off to switch between blower and trimmer usage.
Therefore, there remains a need for an improved yard tool that combines both aspects of blowing debris and trimming vegetation that does not require disassembly of the yard tool to switch between blowing and trimming, that does not require the attachment of accessories to convert between blowing and trimming, that does not result in over heating, and that does not require the motor of the yard tool to be stopped to convert between blowing and trimming, among others benefits and advantages.
The preferred embodiments of the present invention addresses this need by providing a yard tool having a combination blower and trimmer assembly including a blower and a trimmer head that are independently and separately operable.
To achieve this and other advantages, in general, in one aspect, a combined blower and line trimmer assembly for use in connection with a yard tool having an elongated boom, and a drive shaft operatively connected to a motor for rotating the drive shaft is provided. The combined blower and line trimmer assembly includes a blower housing connected to the elongated boom of the yard tool. The blower housing has an interior cavity, an air inlet to said interior cavity, and an air outlet to said interior cavity. An impeller is disposed for rotation about an axis of rotation within said interior cavity to draw air into said interior cavity through said air inlet and to discharge air through said air outlet when said impeller is caused to rotate. Opposed upper and lower clutch bells are disconnected and separately rotatable. The upper clutch bell is connected to said impeller and fixed therewith for conjoined rotation. The lower clutch bell has an output shaft connected therewith for conjoined rotation. A string trimmer head is removably attached to said output shaft for conjoined rotation. A clutch having one or more centrifugal operated clutch shoes is operatively connected to the drive shaft for conjoined rotation therewith. The clutch is alternately positionable between within said upper clutch bell and within said lower clutch bell. When said clutch is disposed within said upper clutch bell said clutch shoes are operable to engage said clutch and said upper clutch bell together to operatively engage the drive shaft with said impeller to axially rotate said impeller about the axis of rotation. When said clutch is disposed within said lower clutch bell said clutch shoes are operable to engage said clutch and said lower clutch bell together to operatively engage the drive shaft with said output shaft to rotate said output shaft and said string trimmer head connected to said output shaft about the axis of rotation, whereby said impeller and said line trimmer assembly connected to said output shaft are independently and alternately operable.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.
Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the description serve to explain the principles of the invention, in which:
Referring now to the drawings, in
Referring now to
Blower 26 includes blower housing 28 having an upper housing 30 and a lower housing 32 mated together by a plurality of cooperating holes and fasteners positioned about the periphery thereof, respectively. The upper housing 30 and lower housing 32 together form an interior cavity in which an impeller is rotatably disposed. The blower housing 28 further includes an air inlet 34 (best shown in
With continued reference to
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Referring now to
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An upper clutch bell or impeller clutch bell 92 and a lower clutch bell or trimmer head clutch bell 94 are attached in an opposed and facing relationship to the impeller 56 and inward end 80 of the trimmer head drive shaft 74, respectively. Impeller clutch bell 92 is positioned within impeller clutch bell recess 96 centrally located on the bottom of the impeller 56. Impeller clutch bell 92 is fixedly attached to the impeller 56 for conjoined rotation therewith. Impeller clutch bell 92 includes an opening 98 coaxially aligned with axis 58 and bore 72 of the impeller hub 60. Trimmer head clutch bell 94 is fixedly attached to trimmer head drive shaft 74 for conjoined rotation therewith.
A centrifugal clutch 100 is disposed for reciprocation along axis 58 between impeller clutch bell 92 and trimmer head clutch bell 94. As shown, centrifugal clutch 100 is positioned within trimmer head clutch bell 94. Clutch drive shaft 102 is fixedly attached at end 104 to clutch 100, and extends upwardly therefrom along axis 58 freely through opening 98 of impeller clutch 92, bore 72 of impeller hub 60, and bore 50 of upper housing hub 46. In other words, opening 98, bore 72, and bore 50 each have an internal diameter greater than the diameter of the clutch drive shaft 102 such that clutch drive shaft is free from engagement with the same, respectively. The opposite end 106 of the clutch drive shaft 102 is connected to end 108 of drive shaft 110 by shaft coupling 112. To this end, clutch drive shaft 102 is driven by drive shaft 110 connected to motor 18 for rotation about axis 58. The operation of centrifugal clutches is well known in the art, therefore a full discussion of such operation is not required here. However, briefly, when the clutch 100 reaches a certain RMP, the clutch activates to engage either the impeller clutch bell 92 or the trimmer head clutch bell 94 to engage the same to drive shaft 110, thereby driving the impeller or trimmer head, respectively. When RMP of the clutch 100 drops below the engagement RMP the clutch disengages the respective clutch bell. It is important to note, clutch 100 will not operate to engage while motor 18 is at idle speed, thereby permitting the clutch to be shifted between the impeller clutch bell 92 and the trimmer head clutch bell 94.
Lever or actuator 114 (
In operation, it can now be understood, a user starts the motor 18 in a conventional manner, and while the motor is at idle speed, the user operates the actuator 114 to select either the blower 26 or the line trimmer 28 for operation, as described above. Once the selection is made, the user manipulates the motor throttle to raise the motor rpm and thus cause the clutch 100 to engage either the impeller clutch bell 92 or the trimmer head clutch bell 94 to drive the same according to the user's selection made by the actuator 114.
For example, should the user desire to trim vegetation, motor 18 is allowed to be brought to idle speed, then the user operates actuator 114 to select the trimming mode. By selecting the trimming mode, the actuator 114 is operated to shift clutch 100 in position to be engaged with the trimmer head clutch bell 94. The user then operates the motor throttle to raise the motor speed to a sufficient rmp to cause the clutch 100 to engage the trimmer head clutch bell 94, thereby connecting motor drive shaft 110 to the trimmer head 28 to drive the same. When the user desires to operate blower 26, such as for example, to remove vegetation debris, the user releases the motor throttle allowing the motor speed to drop to idle speed. With the motor 18 at idle speed, the user is able to once again operate actuator 114 to select the blowing mode. By selecting the blowing mode, the actuator 114 is operated to shift clutch 100 in position to be engaged with the impeller clutch bell 92. The user then operates the motor throttle to raise the motor speed to a sufficient RMP to cause the clutch 100 to engage the impeller clutch bell 92, thereby connecting motor drive shaft 110 to the impeller 56 to drive the same. To this end, a user is not required to stop the motor 18 to select the desired operation mode and is not required to detach or attach the trimmer head to switch between trimming and blowing operating modes.
An added benefit of the invention, is the trimmer head 28 or the blower 26 are not operated during dwell periods while the motor is running. This has the added benefit during dwell periods of reducing heat in the assembly 12, reducing noise created by either the blower 26 or trimmer head 28, and protecting the user from injury caused by contact with the cutting blades of the trimmer head.
A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
