WO2024075030A1

WO2024075030A1 - A mechanism for preventing the freefall of a machining assembly

Info

Publication number: WO2024075030A1
Application number: PCT/IB2023/059952
Authority: WO
Inventors: Prakash Khandelwal
Original assignee: Prakash Khandelwal
Priority date: 2022-10-04
Filing date: 2023-10-04
Publication date: 2024-04-11

Abstract

The present invention relates to the mechanism (100) for preventing the freefall of a machining assembly. The mechanism (100) consists of a coupler (20) on a fixed frame (30), a feeder shaft (40) for the rotary motion of a handle (51), the handle (51) for adjusting the feeding motion, and a locking shaft (80) connected to the handle (51). This locking shaft (80) can move between two positions. The first position (100a) is operable in which an operator can operate mechanism (100) freely. In a second position (100b) the mechanism (100) is non-operable to prevent the free fall of the machine assembly. Both positions are achieved by engaging and disengaging of a locking ball (70) and grooves (22) arranged in the coupler (20).

Description

A Mechanism for preventing the Freefall of a Machining Assembly Field of the Invention

[0001] The present invention relates to machine tools/Drilling machines/Magnetic drilling machines/Power Tools. More particularly, the present invention relates to a mechanism for preventing the freefall of a machining assembly .

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. Some of these machine tools are manual feed machines. Manual feed machines are the machine in which a feed for a specific operation (drilling, milling etc) is given manually. Similarly, some of these machines are auto-feed machines. The auto-feed machines are machines in which a feed for specific operation is given by a prime mover. A Prime mover can be a motor.

[0003] The Prior art machine tools (200) (Figure 1) generally include a machining assembly (220) which is movably attached to a pillar (230) of the machine tool (200). The machine tool (200) has an adapter to accommodate an operation tool (250). The operation tool (250) can be a drill bit, milling tool etc. When these machine tools (200) include the provision of an auto-feed provision, when the machine tool (200) operated to change from a manual mode to an autofeed mode, due to improper locking or any such machine defects, the machining assembly (220) falls from an upside position (220a) to a downside position (220b) under gravity. This can be referred as “The Free fall” of machining assembly.

[0004] As of date, there are no mechanisms to avoid the freefall of a machining assembly of a machine tool//Drilling Machines/Magnetic Drilling machines/Power Tools.

[0005] Therefore, there is a need for a mechanism for preventing the freefall of a machining assembly..

Objects of the Invention

[0006] The object of the present invention is to provide a mechanism for preventing the freefall of a machining assembly .

[0007] Another object of the present invention mechanism for preventing the freefall of a machining assembly is to provide safe smooth damageless working

Summary of the Invention [0008] According to the present invention, a mechanism is provided for preventing the freefall of a machining assembly . The mechanism serves to prevent the freefall of a machining assembly. The mechanism comprises several key components: a feeder shaft responsible for providing rotary motion for machining processes, a handle connected to the feeder shaft's outward end for adjusting feeding motion, and a locking shaft situated inside the feeder shaft. The locking shaft's connection to the handle enables its axial movement within the feeder shaft, allowing it to shift between two positions: a first position (100a) and a second position (100b).

[0009] Additionally, a coupler is attached to the feeder shaft, with one end fixed to a frame, featuring grooves within the coupler. The feeder shaft consists of at least one locking ball placed in a recess section. These locking balls engage with the locking shaft and the grooves within the coupler. The movement of the locking shaft controls the engagement or disengagement of the locking balls with the grooves in the coupler. A locking piece surrounds part of the locking shaft, and a locking spring connects to the locking piece and a stopper, providing the necessary bias.

[0010] In the first position (100a), the feeder shaft is operable, facilitating the machining process. When the handle is pulled, the locking shaft moves toward the stopper, compressing the locking piece and the locking spring. This action disengages the connection between the locking balls and the grooves in the coupler. In the second position (100b), the feeder shaft is non-operable, preventing the free fall of the machining assembly. Upon releasing the handle, the locking spring retracts the locking shaft towards the handle. The locking piece compresses the locking balls towards the grooves of the coupler, engaging them and locking the feeder shaft into a non-operable condition, thus preventing the free fall of the machining assembly.

[0011] This mechanism includes various features to ensure safety and ease of operation. In the first position (100a) of the mechanism, when the handle is pulled outwardly away from the feeder shaft, it causes the locking shaft to move inwardly. This movement enables the locking balls to make contact with an engagement portion of the locking piece. As a result, the locking balls facilitate the disengagement of the grooves from the locking shaft and the coupler, allowing the handle of the machine tool to be operated freely. This configuration ensures that the feeder shaft remains unlocked for machining operations.

[0012] Conversely, in the second position (100b), when the handle is released inwardly, the locking balls engage with the grooves of the coupler. This engagement creates contact between the locking shaft and the grooves of the coupling body, effectively preventing the free movement of the feeder shaft. This locking mechanism ensures that the machining assembly remains securely in place, preventing any unintended freefall during machine tool operations.

[0013] Importantly, this mechanism provides easy switching between the locked and unlocked positions, allowing operators to effortlessly switch between these states. This feature reduces the physical effort required during machine tool operation, enhancing both safety and operational efficiency. This mechanism is particularly suitable for various types of machine tools such as drilling, milling, or broaching machines, where precise control and safety are paramount concerns.

Brief Description of the Drawings

[0014] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.

[0015] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0016] 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:

[0017] Figure 1 shows a schematic view of the existing machine tool (Prior art);

[0018] Figure 2 shows a cross-sectional view of a mechanism for preventig the freefall of a machining assembly in the first position in accordance with the present invention;

[0019] Figure 2a shows a perspective view of a coupler of the mechanism shown in Figure 2; and

[0020] Figure 3 shows a cross-sectional view of a mechanism for preventing the freefall of a machining assembly in the second position in accordance with the present invention. Detailed Description of the Invention

[0021] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the and scope of the present disclosure as defined by the appended claims.

The present invention relates to the mechanism for preventing the freefall of a machining assembly of a machine tool. The mechanism consists of a coupler on a fixed frame, a feeder shaft for the rotary motion of a handle, a handle for adjusting the feeding motion, and a locking shaft connected to the handle. This locking shaft can move between two positions. The first position is operable in which an operator can operate the mechanism freely and in the second position the mechanism is non- operable to prevent the free fall of the machine assembly. Both positions are achieved by engaging and disengaging a locking ball and grooves arranged in the coupler.

[0022] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.

[0023] Referring now to figure 2, a cross-sectional view of a mechanism (100) for preventing the freefall of a machining assembly in accordance with the present invention is illustrated. The mechanism (100) for preventing the freefall of a machining assembly comprises a feeder shaft (40), a handle (51), a locking shaft (80), and a coupler (20).

[0024] The feeder shaft (40) is arranged on a side portion of the mechanism (100). The feeder shaft (40) in the mechanism (100) provides a rotary motion needed to spin the drill bit and the controlled downward feed into the workpiece. The feeder shaft (40) rotates the drill bit held in a chuck assembly (not shown) at its front end. The feeder shaft (40) incorporates a feed mechanism (not shown) that allows operators to control and adjust the depth and rate of drilling using a feed handle or control lever. This controlled feed, combined with rotational motion, enables precise and efficient drilling, making the feeder shaft a fundamental component for various drilling tasks across woodworking, metalworking, construction, and other industries. In an embodiment, there may be the use of a screw feed mechanism, pneumatic or hydraulic feeding, rack and pinion mechanism or linear actuators, or a pawl and ratchet mechanism, a person skilled in the art can arrange any component in place of the feeder shaft (40). [0025] The handle (51) is arranged along with the feeder shaft (40) at the outer end, by turning the handle (51), the operator can adjust the feeding motion of the feeder shaft (40). This adjustment allows for precise control over the depth and rate of drilling or machining, ensuring that the tool operates effectively and produces the desired results. The handle (51) is linked to the locking shaft (80) within the feeder shaft (40). When the handle (51) is pulled outwardly, it causes the locking shaft (80) to move inwardly, enabling the feeder shaft (40) to operate in a first position (100a). This position allows for the drilling or machining process to take place, when the handle (51) is released inwardly, it triggers the locking shaft (80) to move back toward the handle (51). This action engages the locking mechanism, including the locking balls (70), grooves (22), locking piece (90), and locking spring (120), effectively rendering the feeder shaft (40) non-operable in a second position (100b). This safety mechanism (100) prevents unintended freefall of the machining assembly, enhancing safety during machine tool operations.

[0026] In the present embodiment, the handle (51) has three shafts coming out from the core of the handle (51) that the operator can hold while operating the handle (51) providing the function that the operator can operate the mechanism (100) freely and lock the mechanism (100) by just pulling and releasing the handle (51). The person skilled in the art can make any alternative of handle (51) that provides the same function. [0027] The locking shaft (80) is arranged within a hollow interior of the feeder shaft (40). The locking shaft (80) is connected to the handle (51). This connection allows the operation of the handle (51) to influence the axial movement of the locking shaft (80) inside the feeder shaft (40). When the operator operates the handle (51), it results in the locking shaft (80) is capable of moving between two distinct positions, namely a first position (100a) and a second position (100b) shown in Figure 4. In an embodiment, there may be the use of an electronic locking system, or electromagnetic clutch, A person skilled in the art can use any alternate arrangement in place of the locking shaft (80).

[0028] The coupler (20) is positioned on the feeder shaft (40). One end of the coupler (20) is securely attached to the fixed frame (30) within the mechanism (100). This attachment point involves bolts in an embodiment there may be welds, or other suitable fastening methods to ensure stability and rigidity a person skilled in the art can use any alternative in place of bolt arrangement. The interior of the coupler (20) features grooves (22) that are positioned to engage with the locking balls (70). These grooves (22) are integral to the locking and unlocking mechanism (100), allowing for controlled movement and locking of the feeder shaft (80). Within the coupler, there is often a recess section (130) where the locking balls (70) are placed. This recess section (130) provides a designated location for the locking balls (70) to interact with the grooves (22) and the locking shaft (80). [0029] The coupler (20) is arranged with one or more locking balls

(70), situated within a recessed area (130) inside the coupler (20) as shown in figure 4. These locking balls (70) are intricately designed to establish engagement with both the locking shaft (80) and the grooves (22) located within the coupler (20). In this embodiment there is a plurality of locking balls (70) arranged in the coupler (20), in an embodiment, there may be single balls, or fluid arrangement or a person skilled in the art can make any arrangement that locks and unlocks the mechanism (100). The movement of the locking shaft (80) within the feeder shaft (40) controls the interaction of these locking balls (70) with the grooves (22) inside the coupler (20). Depending on the position of the locking shaft (80), the locking balls (70) can either engage securely with the grooves (22) to lock the feeder shaft (40) or disengage to enable free movement, contributing to the safety and functionality of the machining assembly. The person skilled in the art can use or arrange any parts that engage and disengage the locking balls (70) to lock and free up the mechanism (100).

[0030] This locking shaft (80) is arranged along with a locking piece (90) characterized by its tapered end. The presence of this locking piece controls the engagement and disengagement of the locking balls (70) within the grooves (22) arranged in the coupler (20).

[0031] The locking shaft (80) is further attached with a locking spring (120), and the locking spring (120) arranged surrounds the locking shaft (80). The locking spring (120) is linked to the locking piece (90) arranged on the locking shaft (80), while the other end is connected to a stopper (140). The primary function of this locking spring (120) is to exert a consistent force that biases the locking piece (90). This biasing action is pivotal for the mechanism's operation, as it influences the engagement and disengagement of the locking balls (70) within the system. In an embodiment there may be the use of a rubber damper, pneumatic or hydraulic cylinder, mechanical linkage, or torsion bars, the person skilled in the art can arrange any alternative in place of the locking spring.

[0032] In the first position (100a) as shown in Figure 1, of the mechanism (100), the feeder shaft (40) is set to enable the machining process. When an operator pulls the handle (51), it initiates a specific sequence of movements. The locking shaft (80), which is connected to the handle (51), starts moving towards a designated stopper (140). This motion leads to the compression of the locking piece (90), assisted by the presence of the locking spring (120). As the locking piece (90) compresses, disengage the connection between the locking balls (70) and the grooves (22) present on the coupler (20). This disconnection allows the feeder shaft (40) to move freely, facilitating the machining processes without any hindrance. Essentially, pulling the handle (51) in this first position sets the feeder shaft (40) in a mode that permits the machining operation to take place smoothly. [0033] In the second position (100b) of this mechanism (100), the feeder shaft (40) is non-operable to serve as a safety feature, preventing the free fall of the machining assembly. When the operator releases the handle (51). The locking spring (120), which surrounds and is connected to the locking shaft (80), starts to retract the locking shaft (80) towards the handle (51). As this retraction occurs, the locking piece (90), which has a tapered end, compresses the locking balls (70) within the feeder shaft (40), moving them towards the grooves (22) present on the coupling body. This compression results in the engagement between the locking balls (70) and the grooves (22) of the coupler (20). This specific connection effectively locks the feeder shaft (40) in place, configuring it into a non-operable condition. The feeder shaft (40) ensures that the machining assembly remains secure and prevents any accidental free fall, enhancing safety during machine tool operation.

[0034] This mechanism (100) is designed to prevent the accidental freefall of a machining assembly, ensuring both safety and control during its operation. The mechanism (100) consists of several key components: a feeder shaft (40) responsible for providing rotary motion to drive cutting tools or workpieces, a handle (51) connected to the feeder shaft for adjusting its feeding motion, and a locking shaft (80) housed within the feeder shaft (40). The locking shaft (80) can move between two positions: a first position (100a) and a second position (100b). Additionally, a coupler (20) is attached to the feeder shaft (40), featuring a groove (22) for engagement. [0035] Inside the feeder shaft (40), there is at least one locking ball (70) situated in a recess portion (130). This locking ball (70) can connect with the locking shaft (80) and the grooves (22) of the coupler (20). A locking piece (90) with a tapered end surrounds part of the locking shaft (80), and a locking spring (120) is connected to the locking piece (90) and a stopper (140), providing bias. In the first position, pulling the handle (51) moves the locking shaft (80) inward, disengaging the connection between the locking balls (70) and the grooves (22) of the coupler (20), allowing the machine tool to operate. In the second position, releasing the handle (51) causes the locking spring (120) to retract the locking shaft (80), engaging the locking balls (70) with the grooves (22) of the coupler (20), preventing the freefall of the machining assembly and ensuring a non- operable condition.

[0036] This mechanism finds application in various types of machine tools such as drilling, milling, or broaching machines, where it facilitates controlled movement of the feeder shaft (40) and the associated machining processes. It allows operators to effortlessly switch between locked and unlocked states, enhancing operational efficiency and reducing the need for manual effort during machine tool operation.

[0037] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

Claims

We Claim:

1. A mechanism (100) for preventing the freefall of a machining assembly comprising: a feeder shaft (40) arranged on a side portion of the mechanism (100) to provide rotary motion to drive cutting tools or workpieces, enabling the machining processes; a handle (51) coupled to the feeder shaft (40) at an outward end to adjust the feeding motion of the feeder shaft (40); a locking shaft (80) arranged inside a hollow interior of the feeder shaft (40), one end of the locking shaft (80) is in connection with the handle (51) such that the operation of the handle (51) enables an axial movement of the locking shaft (80) within the feeder shaft (40) wherein the locking shaft (80) is movable between a first position (100a) and a second position (100b); a coupler (20) arranged on the feeder shaft (40) with one end of the coupler (20) connected to a fixed frame (30), and a groove (22) arranged inside the coupler (20); at least one locking ball (70) arranged in a recess portion (130) within the coupler (20), the locking ball (70) is engageably connected with the locking shaft (80) and the grooves (22) of the coupler (20), the movement of the locking shaft (80) enables the locking ball (70) to engage or disengage with the grooves (22) arranged inside the coupler (20). a locking piece (90) with a tapered end surrounding a portion of the locking shaft (80); a locking spring (120) arranged on an end portion of the locking shaft (80), the locking spring (120) surrounds a portion of the locking shaft (80), the locking spring (120) is connected to the locking piece (90) at one end and to a stopper (140) at the other end wherein the locking spring (120) biases the locking piece (90); wherein the feeder shaft (40) is operable in a first position (100a) to facilitate the machining process, upon pulling the handle (51), the locking shaft (80) moves towards the stopper (140), compressing the locking piece (90) along with the locking spring (120), disengaging the connection between the locking balls (70) and the grooves (22) of the coupler (20); and wherein the feeder shaft (40) is non-operable in a second position (100b) to facilitate the prevention of the free fall of the machining assembly, upon releasing the handle (51) the locking spring (120) retracts the locking shaft (80) towards the handle (51), the locking piece (90) compresses the locking balls (70) towards the grooves (22) of the coupler (20) and engage the locking balls (70) and the grooves (22) of the coupler (20), the connection between the locking balls (70) and the grooves (22) of the coupler (20) to lock the feeder shaft (40) to configure a non-operable condition thereby preventing the free fall of the machining assembly.

2. The mechanism (100) for preventing the freefall of a machining assembly as claimed in claim 1, wherein in the first position(lOOa), the handle (51) is pulled to an outward direction away from the feeder shaft (40) causing displacement of the locking shaft (80) in the inward direction, enabling the contact of the locking balls (70) with an engagement portion (110) of the locking piece (90), the movement of the locking ball (70) facilitates the grooves (22) to disengage the locking shaft (80) from the coupler (20) enabling operation of the handle (51) of the mechanism (100).

3. A mechanism (100) for preventing the freefall of a machining assembly as claimed in claim 1, wherein in the second position (100b), the handle (51) is released in an inward direction, the locking shaft (80) moves towards the handle (51) and the locking balls (70) engage with the grooves (22) of the coupler (20) and the locking balls (70) make contact between the locking shaft (80) and the grooves (22) of the coupler (20), this contact prevents the free movement of the feeder shaft (40) which prevents the free fall of the machining assembly.

4. The mechanism (100) for preventing the freefall of a machining assembly as claimed in claims 1, wherein the locking shaft (80) is restored to its original position which comprises a means to reengage the locking balls (70) with the coupler (20) when handle (51) is released, the locking spring (120) retracts the locking shaft (80) towards the handle (51) thereby locking the locking shaft (80) with the coupler (20) by engaging the locking balls (70) with the grooves (22) of the coupler (20).

5. The mechanism (100) for preventing the freefall of a machining assembly as claimed in claims 1, wherein the machine tool is a drilling, milling, or broaching machine, and the feeding mechanism (100) is the movement of the feeder (40) towards a workpiece to perform the operation.

6. The mechanism (100) for preventing the freefall of a machining assembly as claimed in claim 1, wherein the locking balls (70) work as a medium of engagement of the locking shaft (80) and the coupler (20).

7. The mechanism (100) for preventing the freefall of a machining assembly as claimed in claims 1, wherein an operator can operate the mechanism (100) by just pulling the handle (51) and can put the mechanism (100) in lock position by just releasing the handle (51).

8. The mechanism (100) for preventing the freefall of a machining assembly tool as claimed in claims 1, wherein an easy switching between locked and unlocked operation is provided, reducing human efforts during machine tool operation.