EP3272465B1

EP3272465B1 - Multifunctional tool and rapid replacement structure thereof

Info

Publication number: EP3272465B1
Application number: EP15885084.2A
Authority: EP
Inventors: Songnian Chen
Original assignee: Changzhou Toolon Electric Works Co Ltd
Current assignee: Changzhou Toolon Electric Works Co Ltd
Priority date: 2015-03-19
Filing date: 2015-04-13
Publication date: 2020-02-26
Anticipated expiration: 2035-04-13
Also published as: EP3272465A4; EP3272465A1; CN104708606A; WO2016145701A1; CN104708606B

Description

Field of the Invention

The present invention relates to a technical field of a power tool in the mechanical industry, and more particularly, to a multi-function tool for various operations such as cutting and sanding and its quick-exchange structure.

Background of the Invention

The multi-function tool can load and clamp woodworking saw blade, metal saw blade, triangular sand disc and the like. Then the woodworking saw blade or metal saw blade loaded on the multi-function tool can cut the wood or the metal material such as aluminum alloy while the triangular sand disc loaded can sand and polish the board, gypsum board or wall.
The saw blade and the triangular sand disc are mounted on an output shaft of the multi-function tool and the output end face of the output shaft has small bosses uniformly distributed in a circle. The small bosses are used for the positioning of the saw blade and the triangular sand disc. Further, threaded holes are cut on the output shaft and with a hexagonal wrench to tighten the screws, the saw blade or the triangular sand disc is fixed.
When you replace the saw blade or the triangular sand disc, all the screws have to be removed, and then the new triangular sand disc or saw blade is loaded and the screws are again tightened with the hex wrench. So the replacement of the triangular sand disc and the saw blade is not efficient, and the hexagonal wrench is easy to lose to have the multi-function tool not workable. A multi-tool having a quick exchange structure is for example disclosed in DE 10 2012 007924 A1 .

Summary of the Invention

The technical problem to be solved by the present invention is that: to overcome the technical problem of insufficient efficiency of the replacement of saw blades of the multi-function tool of the prior art, the present invention provides a quick exchange structure to quickly exchange and clamp the saw blade but needing no screws to fix the saw blade and its tools.
The technical proposal employed by the invention to solve the technical problem is as below: a quick exchange structure for a multi-function tool, comprising an output shaft assembly in which an elastic collet able to do axial movement is arranged. In the collet a locking shaft is arranged, and the locking shaft is driven to move axially within the elastic collet by an elastic assembly to realize the opening and closing of the elastic collet. By the traditional replacement method, the screws tightening the saw blade or the triangle disc have to be completely removed before the new one is loaded and tightened with a hexagonal wrench. Not only the efficiency is high enough, but also the hexagonal wrench is easy to lose, resulting in the failure of the multi-function tool. The invention needs no screw to fix the saw blade, instead, by rotating rotary knob arranged on the head of the structure, the axial sliding movement of the output shaft assembly and the locking assembly is controlled to release or clamp the saw blade and realize quick exchange.
Further, to facilitate the structural design of the present invention and have the elastic collet and the elastic assembly only axially sliding rather than axially rotating, the following improvements are made: the output shaft assembly comprises a main output shaft and an auxiliary output shaft which are in an integrated structure, the upper part of the auxiliary output shaft is within the lower end of the main output shaft and so the external diameter is larger than the internal diameter of the main output shaft and the internal diameters of the upper part and the lower part are identical. On the inner wall of the main output shaft symmetrical longitudinal straight slots are cut.
The specific structure of the elastic collet to clamp articles is as follows: the elastic collet has an integrated annulus card and an elastic claw arranged under the annulus card. The internal diameters of the annulus card and the elastic claw are identical and matched with the external diameter d of the locking shaft. On the outer ring of the annulus card annulus bosses are symmetrically arranged and the annulus bosses slide upwards and downwards along the longitudinal straight slots. The bottom of the elastic claw has a round step which is at the outer side of the auxiliary output shaft, and the external diameter of the round step is slightly smaller than the internal diameter of the auxiliary output shaft.
The elastic claw is composed of two arc bodies in symmetric shape and the outer contour is columnar. The external diameter of the outer contour is slightly smaller than the internal diameter of the auxiliary output shaft. The upper end face of the two arc bodies and the lower end face of the annulus card are in an integrated structure, and the gap between the two arc bodies forms two vertical slots. The internal and external diameters of the elastic claw are measured in the non-opened up state of the elastic claw, that is, the contraction state.
The structure of the elastic assembly of the invention selected is as follows:
The structure comprises a check ring for fixing arranged inside the main output shaft, a reset spring of the elastic collet, a reset spring of the locking shaft and a circlip for hole. The check ring for fixing is above the circlip for hole and arranged on the upper end of the locking shaft, the annulus card is under the circlip for hole, the reset spring of the elastic collet is sheathed on the locking shaft and the two ends contact in plane with the upper end face of the annulus card and the lower end face of the check ring for fixing, respectively, and the reset spring of the locking shaft is sheathed in the shaft hole of the main output shaft, and the two ends of the reset spring contact in plane with the lower end face of the check ring for fixing and the upper end face of the circlip for hole.
The elastic assembly further comprises a pressing block arranged inside the main output shaft. Above the pressing block a cam and a rotary knob are arranged, and the rotary knob is fixed to the cam with screws and the pressing block is pressed tightly against the check ring for fixing by the rotary knob and the cam. The cam has two spiral conical faces, and any one of the two spiral conical faces can coincide with the other spiral conical face by rotating 180°. And the bottom of the spiral conical face has an arc catching step with a recess. The pressing block comprises a block annulus, two block bosses and a block convex edge; the block bosses are symmetrically arranged on the upper end face of the block annulus, and the upper end of the block annulus is arc like and matched with the arc catching step; the block bosses are symmetrically arranged on the outer ring of the block annulus and slip upwards and downwards along the longitudinal straight slots. The lower end face of the block annulus presses against the upper end face of the check ring.
To clamp and locate the locking shaft, on the output shaft assembly a clamp assembly for the elastic collet is arranged.
The clamp assembly is further improved as follows: on the lower part of the auxiliary output shaft at least two clamping holes are cut symmetrically, and the axis of the clamping holes is vertical to the axis of the auxiliary output shaft. The clamp assembly for the elastic collet comprises a reset spring, a reset sheath and a fixed sheath sheathed on the auxiliary output shaft and for stopping up the clamping holes; the reset sheath is arranged in the clamping holes, and the reset spring is arranged in the reset sheath.
Preferably, the auxiliary output shaft has two clamping holes and the axis of the clamping holes is vertical to a plane A formed by the axial center line of the two vertical slots.
To facilitate the exchange and fixing of the saw blade, downwards along the bottom of the locking shaft a conical face and a locking shaft round step in an integrated structure are arranged; the external diameter of the conical face increases from up down, and the external diameter of the locking shaft round step is slightly larger than the maximum external diameter of the conical face.
The quick exchange structure for multi-function tool further comprises a saw blade; on one end of the saw blade an installation hole and a plurality of locating holes with the diameter identical to the internal diameter of the auxiliary output shaft are cut, and the locating holes are uniformly distributed along the installation hole; and the lower end face of the auxiliary output shaft has a plurality of bosses matched with the locating holes.
Further, to facilitate the fixing of the circlip for hole, inside the main output shaft a check ring slot is cut and the circlip for hole is fixed inside the check ring slot.
Further, the reset spring of the elastic collet, the reset spring of the locking shaft and the reset spring are of a pressure spring.
Further, the check ring for fixing is fixed to the locking shaft with a spring washer and a nut.
Further, to facilitate the installation, an upper bearing and a lower bearing are installed on the output shaft assembly.
Further, to locating the fixing sheath, on the auxiliary output shaft and against the lower end of the fixing sheath a round wire snap ring for shaft is arranged to locate the fixing sheath.
A multi-function tool installed with the quick exchange structure, comprising an enclosure inside which a power unit and a mechanical drive unit are arranged. The mechanical drive unit comprises a quick exchange structure and a shifting fork, and the shifting fork is sheathed on the main output shaft and is connected with the power unit.
The present invention has the following beneficial effect: compared with the prior art, the multi-function tool and its quick exchange structure of the invention has spared the lock screws and a hexagon wrench, and instead uses an elastic collet to lock the saw blade; further the multi-function tool and its quick exchange structure has compact structure and easy operation, and the saw blade is installed or removed only by rotating the rotary knob, so remarkably increasing the work efficiency.

Brief Description of the Drawing

Below is the further description of the present invention based on the drawing and the embodiments.

Figure 1 is a three-dimension structural drawing of the saw blade in a released state of the quick exchange structure of the multi-function tool of the invention.
Figure 2 is a three-dimension structural drawing of the saw blade in a clamped state of the quick exchange structure of the multi-function tool of the invention.
Figure 3 is a structural drawing of the multi-function tool in a released state of the invention.
Figure 4 is a structural drawing of the multi-function tool in a clamped state of the invention.
Figure 5 is a cross-section drawing of A-A in Figure 4.
Figure 6 is a cross-section drawing of B-B in Figure 6.
Figure 7 is a three-dimension structural drawing of the output shaft and the circlip for hole of the quick exchange structure of the multi-function tool of the invention.
Figure 8 is a diagrammatic drawing of Plane A.

In the drawings: 1. Auxiliary output shaft; 2. Rotary knob; 3. Upper bearing; 4. Pressing block; 5. Cam; 6. Screw; 7. Nut; 8. Spring washer; 9. Check ring for fixing; 11. Reset spring of locking shaft; 10. Locking shaft; 12. Shifting fork; 13. Reset spring of elastic collet; 14. Main output shaft; 15. Circlip for hole; 16. Elastic collet; 18. Lower bearing; 19. Fixing sheath; 21. Round wire snap ring for shaft; 22. Saw blade; 23. Conical face; 24. Boss; 25. Reset spring; 26 Reset sheath; 27. Clamping hole; 29. Longitudinal straight slot; 32. Annulus convex edge; 35. Installation hole; 36. Locating hole; 37. Round step of elastic claw; 38. Round step of locking shaft; 39. Check ring slot; 40. Vertical slot; 41. Block annulus; 42. Block boss; 43. Block convex edge; 45. Elastic claw; 46. Annulus card; 50. Enclosure; 51. Spiral conical face; 52. Arc catching step.

Description of Preferred Embodiments

Below is detailed description of the invention based on the drawings. And the drawings are simplified diagrammatic drawings to illustrate the basic structure of the invention and so only the structures related to the invention are displayed.
As shown in Figure 1-8, in the preferable embodiments of the invention, in the output shaft assembly of the quick exchange structure for the multi-function tool an elastic collet 16 able to do axial movement is arranged. In the elastic collet 16 a locking shaft 10 is arranged, and the locking shaft 10 is driven to move axially within the elastic collet 16 by an elastic assembly to so to realize the opening and closing of the elastic collet 16.
The details are provided as follows:
The output shaft assembly comprises the main output shaft 14 and the auxiliary output shaft 1 which are in an integrated structure, the upper part of the auxiliary output shaft 1 is within the lower end of the main output shaft 14 and so the external diameter is larger than the internal diameter of the main output shaft 14 (not larger than the external diameter of the main output shaft 14, and if so, the upper bearing and the lower bearing and the fixing sheath will not be installed onto the main output shaft), and the internal diameters of the upper part and the lower part are identical. On the inner wall of the main output shaft 14 symmetrical longitudinal straight slots 29 are cut. Further the output shaft assembly has the upper bearing 3 and the lower bearing 18.
The elastic collet 16 has the integrated annulus card 46 and the elastic claw 45 arranged under the annulus card 46. The internal diameters of the annulus card 46 and the elastic claw 45 are identical and matched with the external diameter d of the locking shaft 10. On the outer ring of the annulus card 46 the annulus convex edges 32 are arranged and the annulus convex edges 32 slide upwards and downwards along the longitudinal straight slots 29. The bottom of the elastic claw 45 has the round step 37 of elastic claw which is at the outer side of the auxiliary output shaft 1, and the external diameter of the round step 37 of elastic claw is slightly smaller than the internal diameter of the auxiliary output shaft 1 (to ease the installation). The elastic claw 45 is composed of two arc bodies in symmetric shape and the outer contour is columnar. The external diameter of the outer contour is slightly smaller than the internal diameter of the auxiliary output shaft 1, subject to that the elastic claw 45 can be opened up to some angles. The upper end face of the two arc bodies and the lower end face of the annulus card 46 are in an integrated structure, and the gap between the two arc bodies forms two vertical slots 40.
The spring assembly comprises the check ring for fixing 9 arranged inside the main output shaft 14, the reset spring 13 of the elastic collet, the reset spring 11 of the locking shaft and the circlip for hole 15. The check ring slot 39 is cut on the inner ring of the main output shaft 14, the circlip for hole 15 is fixed in the check ring slot 39 and some part extends out of the check ring slot 39, the check ring for fixing 9 is fixed onto the locking shaft 10 with the spring washer 8 and the nut 7; the annulus card 46 is under the circlip for hole 15, the reset spring 13 of the elastic collet is sheathed on the locking shaft 10 and the two ends contact in plane with the upper end face of the annulus card 46 and the lower end face of the check ring for fixing 9, respectively, and the reset spring 11 of the locking shaft is sheathed in the shaft hole of the main output shaft 14, and the two ends contact in plane with the lower end face of the check ring for fixing 9 and the upper end face of the circlip for hole 15.
The elastic assembly further comprises the pressing block 4 arranged inside the main output shaft 14. Above the pressing block 4 a cam 5 and a rotary knob 2 are arranged, and the rotary knob 2 is fixed to the cam 5 with screws 6 and the pressing block 4 is pressed tightly against the check ring for fixing 9 by the rotary knob 2 and the cam 5.
The cam 5 has two spiral conical faces 51, and any one of the two spiral conical faces 51 can coincide with the other spiral conical face 51 by rotating 180°. And the bottom of the spiral conical face 51 has an arc catching step 52 with a recess. The pressing block 4 comprises the block annulus 41, two block bosses 42 and the block convex edge 43 which are integrated; the block bosses 42 are symmetrically arranged on the upper end face of the block annulus 41, and the upper end of the block boss 42 is arc like and matched with the arc catching step 52; the block convex edge 43 is symmetrically arranged on the outer ring of the block annulus 41 and slips upwards and downwards along the longitudinal straight slots 29. The lower end face of the block annulus 41 presses against the upper end face of the check ring 9.
On the output shaft assembly the clamping assembly of the elastic collet is further arranged. On the lower part of the auxiliary output shaft 1 at least two clamping holes 27 are cut symmetrically, and the axis of the clamping holes 27 is vertical to the axis of the auxiliary output shaft 1. The clamp assembly for the elastic collet comprises the reset spring 25, the reset sheath 26 and the fixed sheath 19 sheathed on the auxiliary output shaft 1 and for stopping up the clamping holes 27; on the auxiliary output shaft 1 and against the lower end of the fixed sheath 19 the round wire snap ring for shaft 21 is further arranged for locating the fixed sheath 19; the reset sheath 26 is arranged in the clamping holes 27, and the reset spring 25 is arranged in the reset sheath 26. When two clamping holes 27 are cut, the push force generated by the reset spring drives the reset sheath 26 against the two sides of the elastic claw 45 tightly so to clamp the locking shaft 10. A plurality of clamping holes 27 may be arranged symmetrically if required.
Downwards along the bottom of the locking shaft 10 the conical face 23 and the locking shaft round step 38 in an integrated structure are arranged; the external diameter of the conical face 23 increases from up down, and the external diameter of the locking shaft round step 38 is slightly larger than the maximum external diameter of the conical face 23.
The quick exchange structure for multi-function tool further comprises the saw blade 22; on one end of the saw blade 22 the installation hole 35 and a plurality of locating holes 36 with the diameter identical to the internal diameter of the auxiliary output shaft 1 are cut, and the locating holes are uniformly distributed along the installation hole 35; and the lower end face of the auxiliary output shaft 1 has a plurality of bosses 24 matched with the locating holes 36.
The reset spring 13 of the elastic collet, the reset spring 11 of the locking shaft and the reset spring 25 are of a pressure spring.
A multi-function tool installed with the quick exchange structure of the embodiment, comprising the enclosure 50 inside which the power unit and the mechanical drive unit are arranged. The mechanical drive unit comprises the quick exchange structure and the shifting fork 12, and the shifting fork 12 is sheathed on the main output shaft 14 and is connected with the power unit.
The functions realized by the embodiment are as follows:
The rotary knob 2 rotates counterclockwise to the end, the cam 5 rotates simultaneously as driven by the rotary knob 2, the two symmetric spiral conical faces 51 push the two block bosses 42 on the pressing block 4 and further have the pressing block 4 to move axially, the pressing block 4 pushes the locking shaft assembly to move outwards and the reset spring 13 of the elastic collet simultaneously pushes the elastic collet 16 to move outwards; the elastic claw 45 of the elastic collet 16 contracts inwards under the action of the reset spring 25 and the reset sheath 26; and so when the elastic collet 16 is at the contraction state, the saw blade can be removed or installed then.
When the elastic collet 16 is at the contraction state, the locating holes 36 of the saw blade 22 are sheathed on the boss 24 at the lower end face of the auxiliary output shaft 1; then the rotary knob is rotated to the end clockwise, and so the symmetric spiral conical faces 51 on the cam 5 are separated from the two block bosses 42; the locking shaft assembly move inwards under the action of the reset spring 11 of the locking shaft to reset, and the elastic claw 45 under the joint action of the reset spring 13 of the elastic collet and the conical face 23 of the locking shaft 10 opens up; after the elastic collet 45 opens up, the elastic collet 16 moves inwards as pushed by the round step 38 of the locking shaft 10, the round step 37 of the elastic claw on the elastic collet 16 presses against the edge of the round hole 35 on the saw blade 22 and finally the saw blade 22 is locked tightly. As enlightened by the preferable embodiment of the invention and based on the above description, related technical workers may make various alterations and modifications. The technical range of the present invention is not limited to the descriptions of the patent specification and must be determined based on the range of the claims.

Claims

A quick exchange structure for a multi-function tool, wherein an output shaft assembly in which an elastic collet (16) able to do axial movement is arranged, wherein in the elastic collet (16) a locking shaft (10) is arranged, and the locking shaft (10) is driven to move axially within the elastic collet (16) by an elastic assembly to realize the opening and closing of the elastic collet (16).
The quick exchange structure for a multi-function tool of Claim 1, wherein the output shaft assembly comprises a main output shaft (14) and an auxiliary output shaft (1) which are in an integrated structure, the upper part of the auxiliary output shaft (1) is within the lower end of the main output shaft (14) and so the external diameter is larger than the internal diameter of the main output shaft (14) and the internal diameters of the upper part and the lower part are identical, and on the inner wall of the main output shaft (14) symmetrical longitudinal straight slots (29) are cut.
The quick exchange structure for a multi-function tool of Claim 2, wherein the elastic collet (16) has an integrated annulus card (46) and an elastic claw (45) arranged under the annulus card (46), the internal diameters of the annulus card (46) and the elastic claw (45) are identical and matched with the external diameter d of a locking shaft (10), on the outer ring of the annulus card (46) annulus convex edges (32) are arranged and the annulus convex edges (32) slide upwards and downwards along longitudinal straight slots (29), and the bottom of the elastic claw (45) has a round step (37) of elastic claw which is at the outer side of an auxiliary output shaft (1) .
The quick exchange structure for a multi-function tool of Claim 3, wherein the elastic claw (45) is composed of two arc bodies in symmetric shape and the outer contour is columnar, the external diameter of the outer contour is slightly smaller than the internal diameter of the auxiliary output shaft (1), the upper end face of the two arc bodies and the lower end face of the annulus card (46) are in an integrated structure, and the gap between the two arc bodies forms two vertical slots (40).
The quick exchange structure for a multi-function tool of Claim 3, further comprising a spring assembly wherein the spring assembly comprises a check ring for fixing (9) arranged inside the main output shaft (14), a reset spring (13) of the elastic collet, a reset spring (11) of the locking shaft and a circlip for hole (15), the check ring for fixing (9) is above the circlip for hole (15) and fixed onto the upper end of the locking shaft (10), the annulus card (46) is under the circlip for hole (15), the reset spring (13) of the elastic collet is sheathed on the locking shaft (10) and the two ends contact in plane with the upper end face of the annulus card (46) and the lower end face of the check ring for fixing (9), respectively, and the reset spring (11) of the locking shaft is sheathed in the shaft hole of the main output shaft (14), and the two ends contact in plane with the lower end face of the check ring for fixing (9) and the upper end face of the circlip for hole (15).
The quick exchange structure for a multi-function tool of Claim 4, wherein the elastic assembly further comprises a pressing block (4) arranged inside the main output shaft (14), above the pressing block (4) a cam (5) and a rotary knob (2) are arranged, and the rotary knob (2) is fixed to the cam (5) with screws (6) and the pressing block (4) is pressed tightly against the check ring for fixing (9) by the rotary knob (2) and the cam (5).
The quick exchange structure for a multi-function tool of Claim 6, wherein the cam (5) has two spiral conical faces (51), and any one of the two spiral conical faces (51) can coincide with the other spiral conical face (51) by rotating 180°, the bottom of the spiral conical face (51) has an arc catching step (52) with a recess, the pressing block (4) comprises a block annulus (41), two block bosses (42) and a block convex edge (43) which are integrated; the block bosses (42) are symmetrically arranged on the upper end face of the block annulus (41), and the upper end of the block boss (42) is arc like and matched with the arc catching step (52); the block convex edge (43) is symmetrically arranged on the outer ring of the block annulus (41) and slips upwards and downwards along the longitudinal straight slots (29), and the lower end face of the block annulus (41) presses against the upper end face of the check ring (9).
The quick exchange structure for a multi-function tool of Claim 2, wherein on the output shaft assembly a clamp assembly for the elastic collet is further arranged.
The quick exchange structure for a multi-function tool of Claim 8, wherein on the lower part of the auxiliary output shaft (1) at least two clamping holes (27) are cut symmetrically, and the axis of the clamping holes (27) is vertical to the axis of the auxiliary output shaft (1), the clamp assembly for the elastic collet comprises a reset spring (25), a reset sheath (26) and a fixed sheath (19) sheathed on the auxiliary output shaft (1) and for stopping up the clamping holes (27); the reset sheath (26) is arranged in the clamping holes (27), and the reset spring (25) is arranged in the reset sheath (26).
The quick exchange structure for a multi-function tool of Claim 9, wherein two clamping holes (27) are cut and the axis of the clamping holes (27) is vertical to a plane A formed by the axial center line of the two vertical slots (40).
The quick exchange structure for a multi-function tool of Claim 1, wherein downwards along the bottom of the locking shaft (10) a conical face (23) and a locking shaft round step (38) in an integrated structure are arranged; the external diameter of the conical face (23) increases from up down, and the external diameter of the locking shaft round step (38) is slightly larger than the maximum external diameter of the conical face (23).
The quick exchange structure for a multi-function tool of Claim 2, wherein the quick exchange structure for multi-function tool further comprises a saw blade (22), on one end of the saw blade (22) the installation hole (35) and a plurality of locating holes (36) with the diameter identical to the internal diameter of the auxiliary output shaft (1) are cut, and the locating holes are uniformly distributed along the installation hole (35), and the lower end face of the auxiliary output shaft (1) has a plurality of bosses (24) matched with the locating holes (36).
The quick exchange structure for a multi-function tool of Claim 4, wherein inside the main output shaft (14) a check ring slot (39) is cut and the circlip for hole (15) is fixed inside the check ring slot (39).
The quick exchange structure for a multi-function tool of Claim 9, wherein the reset spring (13) of the elastic collet, the reset spring (11) of the locking shaft and the reset spring (25) are of a pressure spring.
The quick exchange structure for a multi-function tool of Claim 5, wherein the check ring for fixing (9) is fixed to the locking shaft (10) with a spring washer (8) and a nut (7).
The quick exchange structure for a multi-function tool of Claim 1, wherein an upper bearing (3) and a lower bearing (18)are installed on the output shaft assembly.
The quick exchange structure for a multi-function tool of Claim 9, wherein on the auxiliary output shaft (1) and against the lower end of the fixing sheath (19) a round wire snap ring for shaft (21) is arranged to locate the fixing sheath (19).
A multi-function tool in which the quick exchange structure mentioned in any claim of Claims 1-17 is installed, wherein the multi-function tool comprises an enclosure (50) inside which a power unit and a mechanical drive unit are arranged, the mechanical drive unit comprises a quick exchange structure and a shifting fork (12), and the shifting fork (12) is sheathed on the main output shaft (14) and is connected with the power unit.