[0001] The present invention relates to drilling machines. More particularly, the present invention relates to a power feeding mechanism for a drilling machine.

Background of the invention

[0002] Feeding mechanisms are used in machine tools such as drilling, milling, broaching etc., to provide continuous motion of either a machining tool or a workpiece towards or away from each other. In drilling machines, a handle is rotated manually to provide linear motion to a drill chuck which rotates the drill bit to perform drilling operation. In existing manual drilling machines, the operator exerts a force on the workpiece which exceeds failure ultimate strength of the workpiece to make a hole. However, in existing manual drilling machines, the major part of the force for making the hole has to be exerted by the operator only, which leads to user fatigue. To address this problem, auto feed drilling machines are used, but these machines involve electrical/electronic components which increases complexity of the machine. Also in existing drilling machines, due to prolonged use, there is possibility of the drill chuck to fall freely due to gravity because of wear of gearing arrangement within the machine, which leads to accident. [0003] Therefore, there is a need for a feeding mechanism for a drilling machine which overcomes one or more drawbacks of the above mentioned prior art.

Objects of the invention

[0004] The object of the present invention is to provide a power feeding mechanism for a drilling machine.

[0005] Another object of the present invention is to provide a power feeding mechanism for a drilling machine, which reduces manual efforts to provide drilling feed.

[0006] Further object of the present invention is to provide a power feeding mechanism for a drilling machine, which prevents accidents while operating the drilling machine.

[0007] Further the object of the present invention is to provide a mechanism for preventing free fall of machine head/gearbox & motor.

[0008] Further the object of the present invention is to improve the annular cutter life by smooth feeding of the cutter into the workpiece

Summary of the invention

[0009] According the present invention, a power feeding mechanism for a drilling machine is provided. The power deeding mechanism includes a frame, a feeding shaft having a feeding gear mounted on the frame, a handle, a cluster gear, and a rack. The handle is connected to the feeding shaft to facilitate the rotational motion of the feeding shaft upon rotation of the handle. The handle is ergonomically designed for ease of operation and efficient transfer of rotational motion to the feeding shaft.

[0010] The feeding shaft is rotatably arranged on the frame.

Specifically, the feeding shaft is rotatably mounted on the frame through a plurality of bearings for smooth and efficient rotational motion of the feeding shaft.

[0011] The feeding gear which is fixedly arranged on the feeding shaft has helical teeth and is adapted to connect with the cluster gear. The feeding gear is integral with the feeding shaft.

[0012] The cluster gear has a first gear and a second gear mounted on a cluster gear shaft. The first gear is of greater diameter than the second gear. The cluster shaft is rotatably arranged on the frame. The first gear is a worm wheel, and the feeding gear engages with the first gear in a worm and worm wheel arrangement.

[0013] Further, the second gear which is arranged on the cluster gear shaft is connected to the rack. The rack includes a cutting tool. The cutting tool is arranged in such a way that the rotational motion of the second gear is converted into linear motion of the rack and the cutting tool during operation.

[0014] The rotation of the handle causes the feeding shaft and feeding gear to rotate, thereby driving the first gear of the cluster gear and subsequently moving the cutting tool linearly through the rack that is connected to the second gear. The cutting tool is replaceable and is adapted to accommodate a variety of drill bit sizes and types for diverse drilling applications.

[0015] In another aspect of the present invention, the cluster gear comprises a housing for enclosing and protecting the first gear and second gear.

[0016] In another aspect of the invention, the power feeding mechanism comprises a locking mechanism configured to immobilize the feeding shaft and feeding gear to maintain the desired position of the cutting tool.

Brief Description of drawings

[0017] The advantages and features of the present invention will be understood better with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:

[0018] Figure 1 shows an isometric view of a power feeding mechanism for a drilling machine in accordance with the present invention; and

[0019] Figure 2 shows a side view of the power feeding mechanism as shown in figure 1.

Detailed description of the invention [0020] An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.

[0021] The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0022] The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

[0023] Referring to figure 1, an isometric view of a power feeding mechanism (100) for a drilling machine is illustrated. In the present embodiment, a feeding operation is the movement of a drill chuck along with a drill bit towards a workpiece to perform a drilling operation. The power feeding mechanism (100) is hereinafter referred to as the mechanism (100).

[0024] The mechanism (100) includes a feeding shaft (20) mounted on a frame (15). The frame (15) is a rectangular box having vertical sides to mount the feeding shaft (20). The feeding shaft (20) is mounted on the frame (15) in such a way that the end portions of the feeding shaft (20) are rotatably received by the vertical sides of the frame (15). Specifically, the end portions of the feeding shaft (20) are rotatably mounted on the frame (15) through a plurality of bearings for smooth and efficient rotational motion of the feeding shaft (20).

[0025] Further, one end of the feeding shaft (20) extends out of the vertical side of the frame (15) to receive a handle (30). The handle (30) is provided to manually rotate the feeding shaft (20). The handle (30) is ergonomically designed for ease of operation and efficient transfer of rotational motion to the feeding shaft (20). It is obvious to a person skilled in the art to use any type of handle (30) to facilitate the rotation of the feeding shaft (20).

[0026] Further, the feeding shaft (20) includes a feeding gear (40) arranged on an end portion of the feeding shaft (20) which is opposite to the end of the feeding shaft (20) that receives the handle (30). The feeding gear (40) has helical teeth and is integral with the feeding shaft (20). The feeding gear (40) is fixedly arranged on the feeding shaft (20) to provide the rotational motion to the feeding gear (40) when the handle (30) is rotated by the operator.

[0027] Further, the feeding gear (40) is connected to a cluster gear

(50) as shown in figures 1 and 2. The cluster gear (50) includes a first gear (50a) and a second gear (50b) mounted on the handle (30) and is ergonomically designed for ease of operation and efficient transfer of rotational motion to the feeding shaft (20)cluster gear shaft (51) as shown in figures 1 and 2. Further, the cluster gear (50) includes a housing (not shown) for enclosing and protecting the first gear (50a) and second gear (50b). The cluster gear shaft (51) is rotatably arranged on the frame (15). The rotational axis of the cluster gear shaft (51) is perpendicular to the rotational axis of the feeding shaft (20) and the feeding gear (40).

[0028] The first gear (50a) and the second gear (50b) are fixedly arranged on the cluster gear shaft (51). The first gear (50a) is rotatably connected to the feeding gear (40). Specifically, the first gear (50a) is a worm wheel and is adapted mesh with the feeding gear (40) that has helical teeth. The first gear (50a) rotates around an axis that is perpendicular to the rotational axis of the feeding gear (40).

[0029] The rotational motion of the first gear (50a) is transferred to the cluster gear shaft (51) and then to the second gear (50b). The diameter of the first gear (50a) is greater than the second gear (50b). The second gear (50b) is connected to a rack (60) to configure a rack and pinion mechanism between the rack (60) and the second gear (50b). The rotational motion of the second gear (50b) is converted to the linear motion of the rack (60). The rack (60) has a first end which is in mesh with the second gear (50b), and a second end adapted to mount a cutting tool (not shown). When the rack (60) moves in a linear direction, the cutting tool moves in the same direction as the rack (60). The cutting tool is replaceable and is adapted to accommodate a variety of drill bit sizes and types for diverse drilling applications.

[0030] In another embodiment of the present invention, the mechanism (100) includes a locking mechanism configured to immobilize the feeding shaft (20) and feeding gear (40) to maintain the desired position of the cutting tool.

[0031] Specifically, during a cutting operation, when an operator rotates the handle (30), the feeding shaft (20) rotates along with the feeding gear (40). The feeding gear (40) rotates the first gear (50a), which in turn rotates the cluster gear shaft (51). Further, the cluster gear shaft (51) rotates the second gear (50b). Due to the rack and pinion mechanism configured between the rack (60) and the second gear (50b), the rotational motion of the second gear (50b) is converted into the linear motion of the rack. The linear motion of the rack (60) facilitates the translational motion of the cutting tool. The connection of the cluster gear (50) between the feeding shaft (20) and the rack provides a mechanical advantage (i.e., multiplication of the input effort), which reduces efforts while rotating the handle (30).

[0032] The motion transfer in the present mechanism (100) is as follows: -

[0033] Therefore, the present mechanism (100) provides an advantage of reducing manual effort during the feeding operation. Also in this mechanism, the cluster gear (50) does not rotate unless the feeder shaft (20) is rotated in either direction, hence the drill chuck cannot come down on its own weight ensuring safety of the operator.

[0034] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.