WO2024089661A1

WO2024089661A1 - Hand tool

Info

Publication number: WO2024089661A1
Application number: PCT/IB2023/060853
Authority: WO
Inventors: Alessandro Melozzi
Original assignee: Alessandro Melozzi
Priority date: 2022-10-28
Filing date: 2023-10-27
Publication date: 2024-05-02

Abstract

A tool (100) comprises a handle (1), a splined shaft (6), a coupling assembly (7) connected to the splined shaft (6) and protruding anteriorly from the handle (1) to accommodate a bit of the tool, a first and a second pawl (C1, C2) mounted on the splined shaft (6), a selector (8) suitable for engaging the first pawl (C1) and the second pawl (C2), operating means (A) mounted in the handle (1) so that they can be operated by the user to move the selector (8), and a rear spring (M1) to push the splined shaft (6) forward; wherein the operating means (A) comprise a metal ring (3) rotatably mounted with respect to the handle (1); the metal ring (3) having a cam slot (31) wherein a pin (81) of the selector is arranged.

Description

HAND TOOL

DESCRIPTION

The present invention relates to a hand tool, specifically to a screwdriver.

Various types of screwdrivers are known on the market, comprising a handle, a shank, and a bit having a head shaped in such a way to be engaged in the head of a screw to drive it into rotation and tighten or unscrew the screw.

The user engages the head of the screwdriver in the head of the screw, manually rotates the handle by about 45° (maximum rotation allowed by the user's wrist) so as to rotate the screw; then the user detaches the head of the screwdriver from the head of the screw to bring his/her wrist back into the starting position and restart the rotation of the screw.

When the user detaches the head of the screwdriver from the head of the screw, there is a risk that the screw is moved out of its screwing position, and therefore the user must use his/her fingers to center the screw in its screwing position.

In addition, every time the head of the screwdriver engages the head of the screw, the movement of the screwdriver tends to tilt the axis of the screw relative to an ideal screwing axis. As a result, proper screwing is not achieved, and the thread of the screw and/or of the female screw into which the screw is to be screwed is stripped.

In addition, it must be considered that the screwing of a screw generally requires more than ten full turns of the screw. Considering that with a traditional screwdriver one has to disengage the head of the screwdriver from the head of the screw about every quarter of a turn, more than 40 disengagements and engagements of the head of the screwdriver in the head of the screw are required to tighten a screw. Such a system makes the tightening of a screw particularly long and complex.

It is the purpose of the present invention to eliminate the drawbacks of the prior art by providing a tool that, when functioning as a screwdriver, is capable of remaining engaged with the screw at all times, both while tightening and untightening the screw.

Another purpose of the present invention is to provide such a tool which, when functioning as a screwdriver, is capable of guiding the screw during the screwing and unscrewing of the screw.

Still another purpose of the present invention is to provide such a tool that is efficient, reliable and easy to use.

A further purpose of the invention is to provide a versatile hand tool suitable for being used as screwdriver, drill, or cable clamp, depending on the type of bit applied in the tool.

These purposes are achieved in accordance with the invention with the features of independent claim 1 .

Advantageous achievements of the invention appear from the dependent claims.

The tool according to the invention is defined by claim 1 .

Further features of the invention will appear clearer from the following detailed description, referring to a purely illustrative and therefore non-limiting form of its embodiment, illustrated in the appended drawings, wherein:

Fig. 1 is a perspective view illustrating the hand tool according to the assembled invention;

Fig. 1 A is an exploded perspective view, illustrating some elements of the tool of Fig. 1 ;

Fig. 1 B is an enlarged view of a detail of Fig. 1 A.

Fig. 1 C is a perspective view, illustrating the components of Fig. 1 A in assembled condition and an exploded view of other components of the tool according to the invention;

Fig. 2 is an axial sectional view of the tool of Fig. 1 ;

Fig. 2A is an enlargement of a detail of Fig. 2, illustrating two pawls;

Fig. 2B is an enlargement of a detail of Fig. 2, illustrating a coupling assembly;

Figs. 3 to 18 are perspective views, illustrating various assembly stages of the tool according to the invention. With the aid of the Figures, a tool according to the invention is described, which is comprehensively indicated with reference numeral 100.

With reference to Figs. 1 , 1 A and 2, the tool (100) comprises an internally hollow handle (1 ) and a splined shaft (6) connected to a coupling assembly (7) suitable for accommodating a bit (not shown in the Figures) that protrudes anteriorly to perform an operation, such as screwing, drilling and the like.

A first pawl (C1 ) is mounted on the splined shaft (6) so that the first pawl can rotate freely on the splined shaft in counterclockwise direction and is locked in rotation in clockwise direction.

A second pawl (C2) is mounted on the splined shaft (6) so that the second pawl can rotate freely on the splined shaft in clockwise direction and is locked in rotation in counterclockwise direction.

Equivalent means, such as freewheels, one-way couplings and the like, can be used instead of the pawls (C1 , C2).

The tool (100) includes a selector (8) suitable for operating the first pawl (C1 ) and the second pawl (C2).

The selector (8) is rotationally locked and can move axially in three positions:

- an intermediate position, wherein the selector engages the first pawl (C1 ) and the second pawl (C2);

- a first position, wherein the selector engages only the first pawl (C1 ); and

- a second position, wherein the selector engages only the second pawl (C2).

Operating means (A) are mounted in the handle (1 ) so that they can be operated by the user to move the selector (8) into the three positions.

Now the case in which the tool (100) is operated as a screwdriver is considered, that is to say the case in which a screwdriver bit is mounted in the coupling assembly (7). When the selector is in the intermediate position, the screwdriver functions in the traditional way. That is, a clockwise or counterclockwise rotation of the handle (1 ) results in a clockwise or counterclockwise rotation of the bit. When the selector is in the first position, the screwdriver only operates for screwing. That is, a clockwise rotation of the handle results in a clockwise rotation of the bit, and a counterclockwise rotation of the handle does not result in a rotation of the bit, which remains engaged on the head of the screw.

When the selector is in the second position, the screwdriver only operates for unscrewing. That is, a counterclockwise rotation of the handle results in a counterclockwise rotation of the bit, and a clockwise rotation of the handle does not result in a rotation of the bit, which remains engaged on the head of the screw.

Referring to Fig. 1 A, the handle (1 ) comprises a body (10) having an axial channel (1 1 ) open at the front and at the back. The handle (1 ) has a shank (12) protruding anteriorly from a flange (13) of the handle. In the flange (13) there are three seats (13A, 13B, 13C): an intermediate seat (13A), a first seat (13B) and a second seat (13C). In the shank (12) there is a slot (12a).

The tool (100) comprises a support assembly (2) mounted in the handle (1 ) and suitable for supporting the selector (8).

The support assembly (2) comprises a rear sleeve (20), an intermediate sleeve (21 ) and a front sleeve (22).

The rear sleeve (20) is suitable for being inserted into the channel (1 1 ) of the handle. The rear sleeve (20) has a radial opening (23) arranged in a rear part of the rear sleeve and a radial hole (24) arranged in a front part of the rear sleeve. The radial opening (23) is suitable for accommodating a C-ring (S).

The intermediate sleeve (21 ) is suitable for engaging in the rear sleeve. The intermediate sleeve (21 ) comprises a collar (25) that radially protrudes outwardly in order to be stopped against a front end of the rear sleeve and engaged in the front sleeve. The intermediate sleeve (21 ) has a radial hole (26).

The front sleeve (22) is suitable for accommodating the two pawls (C1 , C2).

Referring to Fig. 1 B, the front sleeve (22) has an H-shaped slot (27) that comprises a longitudinal section (27a) and two circumferential sections (27b, 27c). The front sleeve (22) comprises a first radial hole (28a), a second radial hole (28b) and a third radial hole (28c). The first and second radial holes (28a, 28b) are suitable for accommodating respective plugs (V1 , V2). The third radial hole (28c) of the front sleeve is of threaded type to allow a screw (V3) to be screwed in.

The front sleeve (22) has a protrusion (29) that protrudes posteriorly from a rear end of the front sleeve to engage the slot (12a) of the shank (12) of the handle, so as to block a rotation of the front sleeve relative to the handle (1 )-

The selector (8) comprises a plate (80) having a pin (81 ) protruding orthogonally from the plate. Two lugs (82a, 82b) protrude from the plate (80) on either side and are inclined downwards relative to the plate.

Two levers (83a, 83b) shaped like plates are suitable for being inserted into the slot (27) of the rear sleeve.

The plate (80) of the selector is inserted into the slot (27) of the rear sleeve so that the pin (81 ) protrudes radially outward from the rear sleeve and the lugs (82a, 82b) operate the respective levers (83a, 83b).

The levers (83a, 83b) have respective projections (84a, 84b) suitable for engaging in the first pawl (C1 ) and in the second pawl (C2), respectively.

With reference to Fig. 2A, the pawls (C1 , C2) have teeth (85) that protrude radially outward. Grooves (86) are generated between the teeth (85) of the pawls. The pawls have an internal thread that engages in the splined shaft (6). The protrusions (84a, 84b) of the levers of the selector can be engaged in the grooves (86) of the pawls in order to lock the pawls.

Returning to Fig. 1 A, a cover sleeve (4) is mounted on the rear sleeve (22) so as to lock the plate (80) of the selector in the rear sleeve. The cover sleeve (4) comprises a centrally arranged slot (40) and a radial hole (41 ) arranged posteriorly and aligned with the slot (40). The slot (40) of the cover sleeve is suitable for being crossed by the pin (81 ) of the selector. The radial hole (41 ) is suitable for being crossed by the screw (V3). A rear spring (M1 ) is arranged in the rear sleeve (20) to push the splined shaft (6) forward. A rear cover (9) is mounted at the rear of the handle (1 ) and mates with a rear end of the rear sleeve (20).

The rear spring (M1 ) has a first end that is stopped against a percussion pin (60) integral with the splined shaft (6) and a second end that is stopped against the rear cover (9). The percussion pin (60) of the splined shaft has a cylindrical tang (61 ) around which a front portion of the rear spring (M1 ) is wound. The rear cover (9) has a cylindrical tang (90) wherein a rear portion of the rear spring (M1 ) is arranged.

Referring to Fig. 1 C, the operating means (A) comprise a metal ring (3) rotatably mounted on the shank (12) of the handle and on the cover sleeve (4). The metal ring (3) has a cylindrical body (30) with a cam slot (31 ) acting as a cam. The slot (31 ) of the metal ring has a helical pattern and extends for an arc of circle of about 60°-90°.

The slot (31 ) of the metal ring is suitable for accommodating the pin (81 ) of the selector. Thus, by turning the metal ring (3), the selector (8) moves axially.

When the pin (81 ) of the selector is in intermediate position in the slot (31 ) of the metal ring (3), the selector (8) engages both pawls (C1 , C2). If the metal ring (3) is rotated counterclockwise, the selector (8) moves axially to the rear, so the first pawl (C1 ) is disengaged. Conversely, if the metal ring (3) is rotated clockwise, the selector (8) moves axially forward, so the second pawl (C2) is disengaged.

Therefore, the metal ring (3) can be disposed in three positions:

- an intermediate position, wherein the pin (81 ) of the selector is in an intermediate position in the slot (31 ) of the metal ring (3) and the selector locks both pawls;

- a first position, wherein the pin (81 ) of the selector is in a first end-of- travel position in the slot (31 ) of the metal ring (3) and the first pawl (C1 ) is unlocked whereas the second pawl (C2) is locked; and - a second position, wherein the pin (81 ) of the selector is in a second end-of-travel position in the slot (31 ) of the metal ring (3) and the first pawl (C1 ) is locked whereas the second pawl (C2) is unlocked.

Markings can be made on the metal ring (3) near the slot (31 ) to indicate the position of the metal ring with reference to the pin (81 ) of the selector.

The metal ring (3) has a collar (32) with a knurled outer surface to facilitate its manual engagement and rotation by the user.

The metal ring (3) has a presser (34) protruding posteriorly from a rear end of the metal ring to engage in the respective three seats (13A, 13B, 13C) (Fig. 1 A) of the handle, depending on the position of the metal ring. For such a purpose, the presser (34) may have a ball-shaped head (36) stressed by a spring. The presser (34) may have a thread in order to be screwed into a hole (33) drilled in a rear end of the collar of the metal ring.

A cap (35) is screwed to a front end of the front sleeve (22), so that the metal ring (3) is rotatably mounted on the cover sleeve (4) between the handle (1 ) and the cap (35).

Referring to Figs. 1 C and 2B, the coupling assembly (7) comprises a cylindrical, internally hollow tang (70) having an axial channel (78). The tang (70) is attached to a front end (66) of the splined shaft.

The tang (70) has two radial holes (71 ) in diametrically opposite positions, which are suitable for accommodating respective balls (72).

A sleeve (73) is mounted to slide axially on the tang (70) of the coupling assembly. A front spring (M2) is interposed between the tang (70) and the sleeve (73). For such a purpose, the tang (70) has an outer collar (76) and the sleeve (73) has an inner collar (75). Therefore, the front spring (M2) is disposed between the outer collar (76) of the tang (70) and the inner collar (75) of the sleeve (73).

A front cap (77) is coupled on a front part of the tang (70) so that the sleeve (73) is stopped against the cap (74) stressed by the front spring (M2). In such a situation, the sleeve (73) pushes the balls (72) into the holes (71 ) of the tang, so that a portion of the balls protrudes internally into the axial channel

must be inserted into the axial channel (78) of the tang.

The sleeve (73) has a tapered inner surface portion (74) with increasing diameter going anteriorly. In view of the above, if the user pushes the sleeve (73) rearward, compressing the front spring (M2), the balls (72) are no longer blocked by the sleeve (73) and the user can extract the bit from the tang (70).

With reference to Figs. 3 to 18, the assembly of the tool (100) is described hereinafter.

With reference to Fig. 3, the support assembly (2) is illustrated in disassembled condition. The intermediate sleeve (21 ) is inserted into the rear sleeve (20). The rear sleeve (20), which contains the intermediate sleeve (21 ), is inserted into the front sleeve (22). Thus the first pin (V1 ) is inserted into the first radial hole (28a) of the front sleeve, so as to block an axial translation of the intermediate sleeve (21 ) inside the front sleeve (22), as shown in Fig. 4.

Referring to Fig. 5, the first pawl (C1 ) is inserted into the front sleeve (22), and the second pin (V2) is inserted into the second radial hole (28b) of the front sleeve, so as to block an axial displacement of the first pawl (C1 ) inside the front sleeve.

Then the second pawl (C2) is inserted into the front sleeve (22).

Therefore, the splined shaft (6) is inserted into the second pawl (C2) and into the first pawl (C1 ). The splined shaft (6) is pushed into the rear sleeve (20) so that its rear end goes beyond the radial opening (23) of the rear sleeve. In such a way, the stop ring (S) can be inserted into the splined shaft (6) through the radial opening (23) of the rear sleeve, as shown in Fig. 6.

Referring to Fig. 7, the splined shaft (6) is extracted from the front sleeve (22) at the front, until the stop ring (S) attached to the splined shaft is stopped against the intermediate sleeve (21 ) inside the rear sleeve (Fig. 2A).

The rear sleeve (20) is inserted in the axial channel (11 ) of the handle, so that the protrusion (29) of the front sleeve (22) is engaged in the slot (12a) of the shank of the handle.

The levers (83a, 83b) of the selector are inserted into the slot (27) of the front sleeve so as to engage with the respective pawls (C1 , C2). The plate (80) of the selector is inserted into the slot (27) of the front sleeve, so that the lugs (82a, 82b) of the plate of the selector are arranged above the respective levers (83a, 83b) of the selector, as shown in Fig. 8.

Referring to Fig. 9, the cover sleeve (4) is fitted onto the front sleeve (22) so that the pin (81 ) of the selector enters the slot (40) of the cover sleeve and the radial hole (41 ) of the cover sleeve aligns with the third radial hole (28c) of the front sleeve.

The rear spring (M1 ) and the percussion pin (60) are inserted from the back into the rear sleeve (20) that is located inside the handle (1 ), so that the percussion pin (60) is stopped and engaged with a rear end of the splined shaft (6).

As shown in Fig. 10, the screw (V3) is inserted into the radial hole (41 ) of the cover sleeve and screwed into the radial hole (28c) of the front sleeve.

The rear cover (9) is screwed to the rear sleeve (20) so as to contain the rear spring (M1 ) inside the rear sleeve, as shown in Figs. 1 1 and 12.

Referring to Fig. 12, the presser (34) is screwed in the hole (33) of the metal ring so that the spherical head (36) of the presser protrudes from the end of the metal ring, as shown in Fig. 13.

Referring to Fig. 14, the metal ring (3) is fitted onto the cover sleeve (4) so that the pin (81 ) of the selector enters the cam slot (31 ) of the metal ring. Depending on the position of the metal ring (3), the percussion pin (36) of the metal ring engages one of the three seats (13A, 13B, 13C) of the handle. In the example of Fig. 14, the pin (81 ) of the selector is in an intermediate position in the cam slot (31 ) of the metal ring; therefore, the percussion pin (36) of the metal ring engages the intermediate seat (13A) of the handle.

With reference to Fig. 15, the tang (70) of the coupling assembly is coupled on the front end (66) of the splined shaft, as shown in Fig. 16. Eventually, the tang (70) is attached to the splined shaft (6) by means of welding.

Referring to Fig. 17, the balls (72) are arranged in the radial holes (71 ) of the tang of the coupling assembly, and the front spring (M2) is arranged around the tang (70) of the coupling assembly, as shown in Fig. 18. Finally, the sleeve (73) of the coupling assembly is fitted onto the tang (70) of the coupling assembly to hold the front spring (M2), and the front cap (77) is attached to the tang (70) in front of the sleeve (73).

Claims

1. Tool (100) comprising:

- an internally hollow handle (1 ) having an axial channel (1 1 ),

- a splined shaft (6) mounted sliding axially to the handle (1 ),

- a coupling assembly (7) connected to the splined shaft (6) and projecting anteriorly from the handle (1 ) to accommodate a bit of the tool,

- a first pawl (C1 ) mounted on the splined shaft (6) so that the splined shaft rotates clockwise when the first pawl translates forward relative to the splined shaft and the splined shaft does not rotate relative to the first pawl when the first pawl translates backward relative to the splined shaft,

- a second pawl (C2) mounted on the splined shaft (6) so that the splined shaft rotates counterclockwise when the second pawl translates forward relative to the splined shaft and the splined shaft does not rotate when the second pawl translates backward relative to the splined shaft,

- a selector (8) suitable for engaging the first pawl (C1 ) and the second pawl (C2); said selector being movable from an intermediate position, wherein the selector engages the first pawl (C1 ) and the second pawl (C2), to a first position, wherein the selector engages only the first pawl (C1 ) and to a second position wherein the selector engages only the second pawl (C2),

- operating means (A) mounted in the handle (1 ) so that they can be operated by the user to move the selector (8) to said three positions, and

- a rear spring (M1 ) arranged in the handle to push the splined shaft (6) forward; wherein the operating means (A) comprise a metal ring (3) rotatably mounted with respect to the handle (1 ); said metal ring (3) having a cam slot (31 ) wherein a pin (81 ) of the selector is disposed.

2. The tool (100) according to claim 1 , wherein said selector (8) comprises a plate (80) from which said pin (81 ) of the selector protrudes orthogonally and two lugs (82a, 82b) protruding from the plate (80) in opposite directions to couple with respective levers (83a, 83b) suitable for engaging with the pawls (C1 , C2), respectively.

3. The tool (3) according to claim 1 or 2, wherein each pawl (C1 , C2) has teeth (85) projecting radially outward defining grooves (86), and said levers (83a, 83b) of the selector have projections (84a, 84b) suitable for engaging with the grooves (86) of the pawls (C1 ; C2).

4. The tool (100) according to any one of the claims, wherein said cam slot (31 ) of the metal ring has a helical pattern and extends for an arc of a circle of 60°-90°.

5. The tool (100) according to any one of the preceding claims, wherein said handle (1 ) has a flange (13) provided with three seats (13A, 13B, 13C): an intermediate seat (13A), a first seat (13B), and a second seat (13C), and the metal ring (3) has a presser (34) protruding posteriorly from a rear end of the metal ring to engage in the respective three seats (13A, 13B, 13C) of the handle, according to the position of the metal ring.

6. The tool (100) according to claim 5, wherein said presser (34) has a head (36) in the shape of a ball stressed by a spring.

7. The tool (100) according to any one of the preceding claims, comprising a support assembly (2) mounted inside the handle (1 ) and suitable for supporting the selector (8).

8. The tool (100) according to claim 7, wherein said support assembly (2) comprises a rear sleeve (20), an intermediate sleeve (21 ) and a front sleeve (22); wherein the rear sleeve (20) is suitable for being engaged in the axial channel (11 ) of the handle; the intermediate sleeve (21 ) is suitable for being engaged in the rear sleeve; the intermediate sleeve (21 ) comprises a collar (25) that protrudes radially outward to stop against a front end of the rear sleeve and engage in the front sleeve; and the front sleeve (22) is suitable for accommodating the two pawls (C1 , C2).

9. The tool (100) according to claim 8, wherein said front sleeve (22) has a slot (27) suitable for accommodating said levers (83a, 83b) and said plate (80) of the selector so that the pin (81 ) of the selector protrudes radially outwardly from the front sleeve (22).

10. The tool (100) according to claim 9, comprising a cover sleeve (4) mounted on the rear sleeve (22), so as to lock said plate (80) of the selector in the rear sleeve; said cover sleeve (4) comprising a slot (40) in central position suitable for being crossed by the pin (81 ) of the selector.

11. The tool (100) according to any one of claims 8 to 10, wherein the rear spring (M1 ) is disposed in said rear sleeve (20) of the support assembly and a rear cover (9) is mounted posteriorly in the rear sleeve (20); the rear spring (M1 ) having a first end that is stopped against a percussion pin (60) mounted at a rear end of the splined shaft (6) and a second end that is stopped against the rear cover (9).

12. The tool (100) according to any one of the preceding claims, wherein said coupling assembly (7) comprises:

- a cylindrically shaped, internally hollow tang (70) having an axial channel (78); said tang (70) being attached to a front end (66) of the splined shaft; said tang (70) having two radial holes (71 ) suitable for accommodating respective balls (72);

- a sleeve (73) mounted sliding axially on the tang (70) of the coupling assembly, so as to interfere with said balls (72) to push the balls (72) into the holes (71 ) of the tang, so that a portion of the balls protrude internally in the axial channel (78) of the tang, creating a narrowing which tightens a bit of the tool to be inserted into the axial channel (78) of the tang;

- a front spring (M2) interposed between the tang (70) and the sleeve (73); and

- a front plug (77) coupled on a front part of the tang (70) so that the sleeve (73) is stopped against the plug (74) stressed by the front spring (M2).

13. The tool (100) according to claim 12, wherein said sleeve (73) has a tapered inner surface portion (74) with an increasing diameter going anteriorly, so that when the user pushes the sleeve (73) backward, compressing the front spring (M2), the balls (72) are no longer blocked by the sleeve (73) and the user can extract the bit from the tang (70).