Technical field

The present invention relates to an electric reciprocating saw, especially an electric jigsaw.

Background

As shown in Fig. 1 and 2, an electric jigsaw in the prior art comprises a main machine 1, a sawblade 4 mounted on the main machine 1 to reciprocally move, and a baseplate 3 supporting the main machine 1 in a fixed height. A bottom surface of the baseplate 3 is rest against a top surface of a material 5 to be cut and is moved along a predetermined cutting path when the electric jigsaw operates. Only a determined part of sawteeth 6 of the sawblade 4 is used in the operation of cutting the material 5 when the electric jigsaw is actuated by a switch 2, so the determined part of sawteeth 6 is worn early and forms a worn part of sawteeth 7 while the other part of sawteeth 8 is still in good condition. Since said worn part of the sawteeth is the main sawing sawteeth of said sawblade, the sawblade has to be exchanged after the determined part of sawteeth is worn, it markedly reduces the service efficiency of said sawblade and increases the cost of production.

Summary of the invention

The present invention provides an electric reciprocating saw to overcome the above described drawbacks, the electric reciprocating saw comprising: a main machine including a driving mechanism mounted on the main machine and a sawblade driven by a driving mechanism of the main machine, extending in linear; a baseplate rest against the material to be cut; and a seat frame between the baseplate and the main machine, characterized in that, the seat frame comprising an upper guide sleeve and a lower guide sleeve mutually nesting each other; a screw rod, one end of the screw rod is mounted on one of the upper guide sleeve and the lower guide sleeve; and an adjustable ring mounted in the other one of the upper guide sleeve and the lower guide sleeve, wherein the upper guide sleeve connects to the main machine, and the lower guide sleeve connects to the seat frame, wherein screw threads are provided on the adjustable ring and the screw rod which are mutually threaded connected, the screw rod and the sawblade extend in the same direction, and the relative height between the upper guide sleeve and the lower guide sleeve is adjusted by the screw threads between the adjustable ring and the screw rod.

Preferably, the upper guide sleeve is a separated component fixedly connects to the main machine or integrates with the main machine; and the lower guide sleeve is a separated component fixedly connect to the baseplate or integrates with the baseplate; and the relative height between the main machine and the baseplate is determined by the relative height between the upper guide sleeve and the lower guide sleeve.

Preferably, the upper guide sleeve and the lower guide sleeve are provided respectively with guide walls and sidewalls extending in the same direction as the sawblade, the guide walls and sidewalls could mutually guide and prevent from relative twisting between the upper guide sleeve and the lower guide sleeve.

Preferably, the electric reciprocating saw further comprises a locking means for locking the screw threaded connection between the adjustable ring and the screw rod, and a limiting means for preventing the screw rod out of the engagement with the adjustable ring.

Preferably, the screw rod and the sawblade extend along in vertical direction.

Preferably, the adjustable ring is mounted into opening slots of the two opposite sidewalls of one of said upper guide sleeve or said lower guide sleeve, and a part of said adjustable ring protrudes outside the sidewalls from the opening slots, wherein an upper end surface and a lower end surface of the adjustable ring are fitted with the opening slots for driving the upper guide sleeve move upwardly or downwardly or driving the screw rod together with the upper guide sleeve to move reciprocally along vertical direction..

Preferably, the locking means is one of a self-locking screw thread, a switch provided on one of the upper guide sleeve or the lower guide sleeve for locking the upper guide sleeve and the lower guide sleeve, or a locking switch for locking the adjustable ring with one of the upper guide sleeve or the lower guide sleeve.

Preferably, the limiting means is one of a limiting step provided on one of the upper or lower guide sleeve which is movable relative to the adjustable ring, no screw thread portion provided on an end of said screw rod, and a projection flange whose radius is greater than that of the screw thread provided on an end of said screw rod.

Preferably, one end of the screw rod is fixedly mounted on an upper wall of the upper guide sleeve, and the upper guide sleeve comprises a least one guide wall extending from the upper wall toward the baseplate in a height direction, and the adjustable ring is mounted into opening slots of the two opposite sidewalls of said lower guide sleeve and protrudes outside the sidewalls from the opening slots, and an upper and lower end surfaces of the adjustable ring are fitted with the opening slots for driving the screw rod together with the upper guide sleeve to move reciprocally along vertical direction.

Preferably, one end of the screw rod is mounted on the bottom of said lower guide sleeve, and the lower guide sleeve comprises at least one guide wall extending from the bottom of lower guide sleeve in a height direction, and the adjustable ring is mounted into opening slots in the two opposite sidewalls of the upper guide sleeve and protrudes outside the sidewalls from the opening slots, wherein an upper and lower end surfaces of the adjustable ring are fitted with the opening slots for driving the upper guide sleeve to move upwardly or downwardly.

Brief description of the Drawings

Figure 1 and 2 are schematic views of an electric jigsaw and its sawblade according the prior art;

Figure 3 and 4 are schematic views of an electric jigsaw and its sawblade according the present invention;

Figure 5 is a schematic view of a connecting means connecting a main machine and a baseplate of the electric jigsaw according an embodiment of the present invention, in which the height of the connecting means is adjustable;

Figure 6 is a schematic view of a connecting means connecting a main machine and a baseplate of the electric jigsaw according another embodiment of the present invention, in which the height of the connecting means is adjustable.

Detailed description of embodiments

As shown in Fig. 3, a bottom surface of a baseplate 3 of the electric reciprocating saw according to the present invention, particularly an electric jigsaw, is rested against an top surface of a material 5 to be cut, and moves along a predetermined cutting path, and a sawblade 4 driven by a driving mechanism of the main machine 1 to move reciprocally is used to cut the material 5. A seat frame 10 is provided between the main machine 1 and the baseplate 3, the height of the seat frame 10 is adjustable, and so the distance between the main machine 1 and the baseplate 3 is adjusted in vertical direction by adjusting the height of the seat frame 10. Since the reciprocal movement amplitude of the sawblade 4 is constant during the reciprocal movement of the sawblade 4, the range of the sawteeth of the sawblade 4 mounted on the main machine 1 for conducting cutting can be adjusted by means of adjusting the distance between the main machine 1 and baseplate 3, and thus it remarkably increases the service efficiency of the sawteeth 9 of the sawblade 4, and reduces the cost of production.

Fig. 5 shows a seat frame 10 of the electric reciprocating saw, particularly the electric jigsaw, according to an embodiment of the present invention, in which the height of the seat frame is adjustable, and the distance between the main machine 1 and the baseplate 3 is adjusted by means of the seat frame 10. The seat frame 10 comprises an upper guide sleeve 11, a lower guide sleeve 14, a screw rod 12, one end of the screw rod is fixedly connected to the upper wall of the upper guide sleeve 11 through screw thread, and an adjustable ring 13 mounted in the lower guide sleeve 14, wherein the adjustable ring 13 is threaded connected with the screw rod 12, and the screw rod 12 is perpendicular to the upper wall.

The upper guide sleeve 11 could be a separated component fixedly connected to the main machine 1 through such as welding, riveting, threaded connecting and so on, or could be formed into one piece with the main machine 1 (the connection strcuture of the main machine 1 is not shown in Fig. 5). Similarly, the lower guide sleeve 14 might be a separated component fixedly connected with the baseplate 3 through such as welding, riveting, threaded connecting and so on, or might be formed into one piece with the baseplate 3.

The adjustable ring 13 is provided with an internal thread, through with which the screw rod 12 is connected. An opening slot 131 is provided in the two opposite sidewalls of the lower guide sleeve 14 respectively, and two opening slots 131 are provided in the upper part of the two opposite walls of the lower guide sleeve and located at a horizontal position with substantial the same height, wherein the two opening slots are oppositely provided. The adjustable ring 13 is mounted horizontally in the two opening slots 131, and a part of the side of the adjustable ring 13 protrudes outside of the sidewall of the lower guide sleeve 13, and an upper end surface and lower end surface of the adjustable ring are fitted with the opening slots 131, and thus the adjustable ring 13 is rotated by operating the adjustable ring 13 through the two opening slots 131. When the adjustable ring 13 is rotated, the screw rod 12 together with the upper guide sleeve 11 can be driven by the internal thread of the adjustable ring 13 to move upwardly or downwardly along vertical direction , and thus driving the main machine 1 to move upwardly or downwardly along vertical direction relative to the baseplate 3, so that the distance between the main machine 1 and the baseplate 3 is adjusted.

The upper guide sleeve 11 and the lower guide sleeve 14 could be moved relative to each other in vertical direction, wherein the upper guide sleeve 11 is provided with a multiple of guide walls extending vertically from the edge of the upper wall, the guide walls are used as the lateral sidewalls of the upper guide sleeve 11. The lower guide sleeve 14 is provided with corresponding lateral sidewalls to fit with the said guide walls of the upper guide sleeve 11, the sidewalls of the lower guide sleeve 14 are provided parallel to the guide walls of the upper guide sleeve 11. When the upper guide sleeve 11 and the lower guide sleeve 14 are moving towards to each other along vertical direction, the guide walls of the upper guide sleeve 11 could be guided by the sidewalls of the lower guide sleeve 14, and when the upper guide sleeve 11 and the lower guide sleeve 14 are nested each other, the twist movement between the upper guide sleeve 11 and the lower guide sleeve 14 could be prevented through the contact between the guide wall of the upper guide sleeve 11 and the sidewalls of the lower guide sleeve 14, and thus the upper guide sleeve 11 and the lower guide sleeve 14 are fitted with each other in a anti-twist manner.

Fig. 6 shows a seat frame 20 of the electric reciprocating saw, particularly the electric jigsaw, according to another embodiment of the present invention, the height of the seat frame 20 is adjustable, and the distance between the main machine 1 and the baseplate 3 can be adjusted by means of the seat frame 20. The operation principle of the seat frame 20 is the same as that of the seat frame 10 of Fig.5, and the seat frame 20 comprises an upper guide sleeve 21, a lower guide sleeve 24, a screw rod 22 and an adjustable ring 23. The distance between the upper guide sleeve 21 and the lower guide sleeve 24 can be adjusted by adjusting the screw thread connection between the adjustable ring 23 and the screw rod 22. Correspondingly, the upper guide sleeve 21 and the lower guide sleeve 24 are provided with guide walls and sidewalls respectively for preventing the twist movement between the upper guide sleeve 21 and the lower guide sleeve 24 when the upper guide sleeve 21 and the lower guide sleeve 24 are moving towards to each other along the vertical direction. The differences between Fig.6 and Fig, 5 are that the screw rod 22 is provided on the lower guide sleeve 24, and the adjustable ring 23 is provided in the upper guide sleeve 21, correspondingly, the upper guide sleeve 21 is provided with opening slots 231 for receiving the adjustable ring 23. The variant of the structure in Fig. 6 does not influence the height adjustment between the upper guide sleeve 21 and the lower guide sleeve 24.

As to the embodiments shown in Fig. 5 and 6, the locking manner for locking the screw-driven between the adjustable ring 13 or 23 and the screw rod 12 or 22 might be a thread self-locking, or a locking switch which is provided on the upper guide sleeve and the lower guide sleeve for locking the upper guide sleeve and the lower guide sleeve, or a locking switch for locking the adjustable ring and the upper guide sleeve or the lower guide sleeve, to prevent rotating of the adjustable ring. In order to prevent the screw rod and the adjustable ring from out of screwing engagement, during the adjustment, meaning overshooting, a limiting step may be provided on the upper or lower guide sleeve which moves relatively to the adjustable ring, or no thread portion is provided on an end of the screw rod, or a projection flange whose radius is greater than the radius of the thread is provided on the bottom of the screw rod, such that the overshooting for the adjustable ring is inhibited. Corrugations may be provided on the external cylindrical surface of the adjustable ring to increase friction and to improve the touch feeling. Furthermore, the fitting measure between the upper guide sleeve and the lower guide sleeve might be that the upper guide sleeve surrounds the lower guide sleeve, or that the lower guide sleeve surrounds the upper guide sleeve, or both partially crossed surround.

The structure and configuration shown in the above described embodiments according to the present invention is only schematic. Although the above described embodiments are detailed described in the present disclosure, many improvement may be available (such as the variant of dimension, size, structure, shape and proportion of every element, material and so on) without departing essentially from teachings and advantages of the subject matter.