AU2018206792B2

AU2018206792B2 - Spiral hole digger

Info

Publication number: AU2018206792B2
Application number: AU2018206792A
Authority: AU
Inventors: Hei Man Raymond LEE; Yong Min LI; Li Hua Xie
Original assignee: TTI Macao Commercial Offshore Ltd
Current assignee: TTI Macao Commercial Offshore Ltd
Priority date: 2017-08-01
Filing date: 2018-07-19
Publication date: 2020-03-19
Anticipated expiration: 2038-07-19
Also published as: AU2018206792A1; CN109315106A

Abstract

An electric spiral hole digger, which is characterized by comprising: a motor; a drill coupled to the motor and adapted to be driven by the motor; a power source connected to the motor and adapted to provide power to the motor; a controller coupled to the motor; and a jam detection device coupled to the controller; wherein the jam detection device is adapted to detect a jam condition encountered by the drill during operation; and the controller controls the motor to stop operating when the jam condition occurs. The invention can realize automatic and timely safe stop work when the hole digger is abnormally working. 10483984_1 (GHMatters) P109328.AU Fig.1

Description

SPIRAL HOLE DIGGER

FIELD OF INVENTION [0001] The invention relates to an outdoor power tool, in particular to a spiral hole digger for digging holes on the ground for seeding, burying, fertilizing and the like.

BACKGROUND [0002] Spiral hole diggers are tools used outdoor to drill down on land or other types of ground to create deep holes. At the output of the spiral hole digger, there is a rotating drill to drill the ground and remove excess earthwork from the ground. The spiral hole digger typically has a handle that can be grasped by a single user or double users to stabilize the body during the drilling process.

[0003] However, existing spiral hole diggers have a problem in that the hole digger has a chance to encounter hard materials such as bricks, tiles, stones, rocks, etc. in the soil during working, thereby causing the drill tool to stick and jam. In the event of a jam, continued high power drive of the drill tool will cause the machine to reverse which has a certain chance of injuring the operators. In addition, traditional spiral hole diggers allow the drill to be drilled into the soil by rotation of the drill as well as application of frictional force by hand, and mainly by human force. This type of operation requires a high level of physical fitness for the operator.

SUMMARY [0004] Accordingly, embodiments of the present invention provide an improved spiral hole digger that overcomes or at least alleviates the above-described technical problems.

[0005] In one aspect, the present invention provides an electric spiral hole digger used outdoor to drill down on land or other types of ground to create deep holes, comprising: a frame; a motor fixed on the frame; two handles mounted on the frame which have mutually perpendicular extending directions; a drill coupled to the motor and adapted to be driven by

12127358_1 (GHMatters) P109328.AU

2018206792 19 Feb 2020 the motor; the drill further comprising a drill bar and a drill bit, and the drill bar having a semi-spiral blade to form a drain groove on the ground, wherein a blade edge of the semi-spiral blade does not extend equally in a radial direction from a drill axis of the drill bar; a power source connected to the motor and adapted to provide power to the motor; a controller coupled to the motor; a controlled coupled to the motor; and a jam detection device coupled to the controller, wherein the jam detection device is adapted to detect a jam condition encountered by the drill during operation, and the controller controls the motor to stop operating when the jam condition occurs.

[0006] Preferably, the jam detection device is a power detection device for the motor. When the power detection device for the motor detects that the power of said motor is greater than the threshold, the controller controls the motor to stop operation.

[0007] More preferably, the power detection device for the motor includes a current detection unit for the motor and a voltage detection unit for the motor. The power of the motor may be computed from the current detected by the current detection unit for the motor and the voltage detected by the voltage detection unit for the motor.

[0008] In one particular embodiment, the power source is an AC adapter adapted to be connected to a mains supply.

[0009] In another particular embodiment, the power source is a DC battery pack adapted to be mounted on the spiral hole digger.

[0010] Another embodiment provides a spiral hole digger that includes a driving device adapted to output a rotational driving force; a drill coupled to the driving device and adapted to be driven by the driving device. In some embodiments the spiral hole digger further comprises an impact device which is coupled to the driving device or motor and converting a portion of a or the rotational driving force from the motor into an impact force in a linear direction, thereby enabling the drill to simultaneously rotate and reciprocate in the linear direction.

[0011] Preferably, the impact device contains a rocking bearing.

[0012] Accordingly, the present invention provides a number of advantages. One of the advantages is that the spiral hole digger according to one embodiment of the present invention is provided with a jam detection device which can monitor the voltage of the voltage

12127358_1 (GHMatters) P109328.AU

2018206792 19 Feb 2020 and the motor in real time, thereby calculating the power of the motor in real-time and determining whether a jam occurs to the drill tool of the hole digger. If it is detected that the operating power of the motor rapidly becomes larger and exceeds the threshold, it can be determined that a jam has occurred, and at this time, the controller can cut off the power supply to the motor in time. Therefore, it can automatically and safely stop the work when the hole digger is working abnormally, thereby avoiding personal injuries to the user due to sudden reversal of the drill.

[0013] In addition, an impact device is integrated in the spiral hole digger according to an embodiment of the present invention, so that the rotational driving force from the driving device such as the motor can be converted into the impact force in the linear direction. Such a impact force in the linear direction can work together with the rotary motion of the drill during the dig eye process, so that the efficiency of hole digger for soil and other types of geology can be greatly increased. This eliminates the need for additional effort by the operator or modifications to the way it is operated, thus reducing the operator's work intensity and speeding up the process of digging eye.

BRIEF DESCRIPTION OF THE DRAWINGS [0014] Further, the performance and advantages of the present invention will be further understood with reference to the remaining part of the specification and the accompanying drawings. The reference numerals of the same components are the same throughout these drawings. In some cases, a sub-tag is placed after a label and a hyphen to represent one of many similar components. When referring to a label but not specifically stating an existing sub-tag, it refers to all of these similar components.

[0015] Fig. 1 is a schematic appearance view of an electric spiral hole digger according to an embodiment of the present invention.

[0016] Fig. 2 is a connection diagram of internal circuit components of an electric spiral hole digger in accordance with another embodiment of the present invention.

12127358_1 (GHMatters) P109328.AU

2018206792 19 Feb 2020 [0017] Fig. 3 is a view showing the internal structure of an impact device of the electric spiral hole digger according to another embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0018] Turning first to Figure 1, a first embodiment of the present invention is an electric spiral hole digger 60. The hole digger 60 includes a frame 66 and two handles 62, 64 mounted on the frame 66. The two handles 62, 64 have mutually perpendicular extending directions so that they can be used to stabilize the spiral hole digger 60 in the horizontal direction better when they are simultaneously grasped by the user. The handles 62, 64 can be grasped independently by one user, or separately grasped by two users. At the center of the frame 66 there are fixed with a speed variator 72 and a motor 80 at the upper end of the speed variator 72. The motor 80 is drivingly coupled to the speed variator 72 to supply a rotational driving force from the motor 80 to the speed variator 72. The motor 80 is further connected to a power source (not shown). The power source is, for example, an AC adapter that includes a power cord and a plug that can be plugged into an electric supply outlet to provide electric power to the motor. Alternatively, the power source is a DC battery pack that is adapted to be mounted on a housing of the spiral hole digger in a detachable manner. The speed variator 72 includes a gear structure and the like which can convert the high-speed rotational force of the original output of the motor into a rotational force with relatively low-speed, but large-torque, thereby facilitating carrying out the digging on soils or other type of geology. At the lower end of the speed variator 72 there is provided with a drill as a power output for carrying out the dig eye of the land. The drill includes a drill bar 68 and a drill bit 70. The drill bar 68 has a semi-spiral blade 69 to form a drain groove, so as to discharge soils from the ground through the rotation of the drill bar 68 to the ground in time during the digging process.

[0019] Turning now to Figure 2, an internal circuit assembly of an electric spiral hole digger in accordance with an embodiment of the present invention includes a power source 74, a microcontroller 78, a trigger switch 76, a motor 80, a motor drive circuit 82, and a current sensor 84. The electric spiral hole digger can have an appearance similar to that of the

12127358.1 (GHMatters) P109328.AU

2018206792 19 Feb 2020 electric spiral hole digger shown in Figure 1. In particular, the microcontroller 78 is supplied with DC power from a power source 74 to drive the microcontroller 78, such as that obtained using an AC-DC converter if necessary. The trigger switch 76 acts as a user input device for the spiral hole digger and provides an operational signal to the microprocessor 78 when it is operated by the user. At the same time, the microcontroller 78 is coupled to the main circuit 75 via a control loop (not shown). The main circuit 75 is located between the power source 74 and the motor 80, thereby enabling the microcontroller 78 to control the supply of power to the motor 80 or not. On the other hand, the current sensor 84 is connected to the motor 80 through the motor drive circuit 82, and is capable of detecting the magnitude of the current flowing through the motor 80 in real time. The motor drive circuit 82 can control the motor 80 in addition to receiving a command of the microcontroller 78, and can also detect the voltage of the motor 80, and thus also functions as a voltage detection unit. The motor 80 is powered by the power source 74, but the microcontroller 78 is responsible for the control of motor 80. The motor drive circuit 82 together with a current sensor 84 constitutes a jam detection device for the spiral hole digger.

[0020] In use, the user activates and stops the spiral hole digger by operating the trigger switch 76. Such activation and deactivation can be achieved by the microprocessor 78 controlling the motor 80 based on signals generated by the trigger switch 76. Thereafter, during operation, the motor drive circuit 82 in the jam detection device collects the working voltage of the motor 80 in real time, and the current sensor 84 collects the working current of the motor 80 in real time. Both the working voltage and the working current are communicated to microprocessor 78 for calculating the real-time operating power of the motor 80. The microprocessor 78 compares the calculated operating power with a predetermined threshold. The threshold will not be reached during normal operating process of the spiral hole digger, but once it is reached, it means that a jam has occurred to the drill. At this time, the microprocessor 78 immediately cuts off the main circuit through the control loop, thereby interrupting the supply of power to the motor 80, stopping the operation, preventing the reversal thereof and injuries to the user's personal safety. After eliminating the problem of a

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2018206792 19 Feb 2020 stuck condition such as a jam, the user can resume the normal operation of the spiral hole digger by turning off the trigger switch 76 and then turning it on again.

[0021] Turning now to Figure 3. In another embodiment of the invention, the electric screw hole digger has an impact device for adding a driving force in a linear direction in addition to a normal rotational driving force. The electric spiral hole digger can have an appearance similar to that of the electric spiral hole digger shown in Figure 1. Specifically, a portion of the structure around the motor shaft 26 of the spiral hole digger is shown in Figure 3. A wobbling bearing 36 is mounted to the motor shaft 26 and is coupled to the rotational arm 37. During use, rotation of the motor shaft 26 causes the wobbling bearing 36 to also rotate. The rotation on the wobbling bearing 36 further causes the rotational arm 37 to reciprocate, thereby driving the drill bit to produce a striking effect by a drill bar impact device (not shown). Therefore, the electric spiral hole digger in Figure 3 is in an impact rotational mode in which both impact and rotational effects are generated.

[0022] Having thus described several embodiments, those skilled in the art will recognize that various modifications, other structures, and equivalents can be used without departing from the spirit of the invention. The above description should not be considered as limiting the scope of the invention as defined by the following claims.

[0023] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

[0024] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS

1. An electric spiral hole digger used outdoor to drill down on land or other types of ground to create deep holes, comprising:

a frame;

a motor fixed on the frame;

two handles mounted on the frame which have mutually perpendicular extending directions;

a drill coupled to the motor and adapted to be driven by the motor; the drill further comprising a drill bar and a drill bit, and the drill bar having a semi-spiral blade to form a drain groove on the ground, wherein a blade edge of the semi-spiral blade does not extend equally in a radial direction from a drill axis of the drill bar;

a power source connected to the motor and adapted to provide power to the motor;

a controller coupled to the motor; and a jam detection device coupled to the controller;

wherein the jam detection device is adapted to detect a jam condition encountered by the drill during operation; and the controller controls the motor to stop operating when the jam condition occurs.
2. The spiral hole digger according to claim 1, wherein said jam detection device comprises a power detection device for the motor; said controller, when said power detection device for the motor detects that the power of said motor is greater than the threshold, controls the motor to stop operation.
3. The spiral hole digger according to claim 2, wherein said power detection device for the motor comprises a current detection unit for the motor and a voltage detection unit for the motor; said power of said motor being computed by the current detected by the current detection unit for the motor and the voltage detected by the voltage detection unit for the motor.

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2018206792 19 Feb 2020
4. The spiral hole digger according to any one of claims 1 to 3, wherein said power source is an AC adapter adapted to be connected to a mains supply.
5. The spiral hole digger according to any one of claims 1 to 4, wherein said power source is a DC battery pack adapted to be mounted on said spiral hole digger.
6. The spiral hole digger according to any one of claims 1 to 5, further comprising:

an impact device which is coupled to the motor and converting a portion of a rotational driving force from the motor into an impact force in a linear direction, thereby enabling the drill to simultaneously rotate and reciprocate in the linear direction.
7. The spiral hole digger according to claim 6 wherein said impact device comprises a wobbling bearing.