CN1045736C - Anti-cut device for chainsaws - Google Patents

Abstract

The invention relates to an anti-split device for a saw blade type electric saw, which can be placed on the workpiece, can be placed on the side of the saw blade, and is in pressure contact with the saw blade at the position where the teeth of the saw blade protrude from the workpiece. The chainsaw has attachable thereto a positioning device that supports the cut guard for positioning the cut guard in the correct operating position even when the depth of cut changes and/or the angle of inclination of the saw blade changes.

Description

Anti-cut device for chainsaws

The present invention relates to an anti-split device for a blade type electric saw which can be placed on a workpiece and mounted on the side of the saw blade and in pressure contact with the blade where the teeth of the blade emerge from the workpiece.

In machines for cutting a metal laminate web into individual boards, such as that described in British Patent 259716, the position of the cut guard and the blade is relatively constant. As a result of this, it is ensured that the cut guard and the saw blade do not interfere functionally, especially when the cutting depth varies. However, the trimmed edges of the material were not neat and had to be reworked and smoothed.

Based on the above-mentioned art, the object of the present invention is to improve this situation.

According to the present invention, the aforementioned objects are achieved by providing a cut protection device for a saw blade that can be placed on the workpiece and mounted on the side of the saw blade and when the teeth of the blade protrude from the workpiece. The coming part is in pressure contact with the saw blade, wherein the anti-split device has at least one positioning device, which can be connected to the chainsaw and supports the anti-split device to make the anti-split device even when the cutting depth changes and/or the saw blade is tilted. When the angle changes, it can still be placed in the correct operating position.

In the practice of the present invention, the anti-splitting device is always used as a part which, in the operating state of the manual circular saw, actively engages the exposed teeth of the workpiece and the saw blade at the same time, so that the anti-splitting device not only acts on the workpiece, but also on the saw blade. Apply force and cooperate with the positioning device to ensure that the cut protection device is placed in the correct operating position. The force exerted by the ripstop prevents a gap from forming between the teeth of the saw blade and the ripstop. Since the anti-splitting device is in close contact with the cutting site of the workpiece, no voids are formed at this site, which are considered to be the cause of cracked cut edges. The cutting line is also more precise as the vibration of the saw blade is damped or even eliminated.

The purpose of the present invention can also be achieved through the following other measures:

The cut guard can be adjusted radially relative to the saw blade so that it can be set.

The pressure of the anti-cut device on the saw blade can be set.

The anti-splitting device has a sensor element which is in pressure contact with the bar body of the saw blade, which supports a part which is in pressure contact with the teeth of the saw blade and is designed as an anti-splitting element.

The sensing element and the anti-cutting component are adjustable in the axial direction of the saw blade.

The cut-off protection element can be adjusted relative to the sensing element, which is designed as a stop means for the cut-off protection element.

The sensor is made of bearing material, while the anti-splitting device is made of a material whose hardness is lower than that of the teeth of the saw blade.

The anti-split device includes a plug, which can be detachably connected to the electric saw and has two anti-split parts, which can be installed on both sides of the saw blade and can be in pressure contact with the saw blade .

The anti-split component is connected to the plug with a joint.

The anti-splitting component cooperates with at least one spring element so that the anti-splitting component is in pressure contact with the saw blade.

The anti-cutting part is provided with a sensing element at the position in contact with the saw blade.

The cut-resistant member is a progressively deflected member of cuttable material.

The cut guard may be articulated to the chainsaw and pivotable about the axis of the saw blade, or about an axis extending parallel to the axis.

The positioning means has the shape of an arm which can be pivoted about an axis extending parallel to the axis of the saw blade or can be adjusted along an arc lying in a plane extending perpendicular to the axis.

The anti-splitting device is cylindrical in cross-section, rotatable about its axis, and constructed of a cuttable material.

The pivot axis of the arm is spaced from the axis of the saw blade by a distance which is the same as the radius of the cylinder ripstop.

The axis of the arm is set directly above the axis of the saw blade and together with the axis defines a plane of extension perpendicular to the surface of the workpiece.

The cut guard has a cylindrical notch opening towards the saw blade.

The radial outside of the anti-splitting device is inclined towards the saw blade.

If the proposed cut guard is used in an electric saw with a saw table, it is appropriate that the part of the cut guard resting against the workpiece is in the contact plane defined by the workpiece and the saw table, or protrudes from the saw table towards the workpiece . This alternative method is particularly suitable when the chainsaw is used to cut rough workpieces.

Another suitable embodiment is that the cut guard is adjustable relative to the saw blade so that it can be set. According to the invention, this method is used particularly advantageously if the manual circular saw is an immersion saw whose immersion depth varies as required. The radial adjustability of the cut guard ensures that it is always at least in pressure contact with the teeth of the saw blade.

Another embodiment of the invention envisages that the cut guard is articulated to the saw and pivotable about the axis of the saw blade, or about an axis extending parallel to this axis. This measure ensures that the anti-splitting device engages effectively with the teeth of the saw blade even when the immersion depth of the saw blade changes during the cutting operation. Another idea is for the cut protection to interact with at least one spring element, by means of which the pressure with which the cut protection acts on the saw blade can be determined. This measure is mainly taken into account that saw blades of different sizes can be used in electric saws.

A further particularly suitable embodiment envisages that the cut-off protection has a sensor element which is in pressure contact with the saw blade body and supports the part which is in pressure contact with the saw blade teeth and is designed as a cut-off protection. This greatly reduces the wear of the parts that are in pressure contact with the teeth of the saw blade, because the sensor transmits the actual pressure generated by the anti-cut device to the saw blade and the anti-cut part that is in active contact with the teeth of the saw blade exerts minimal pressure on the saw blade. pressure. Preferably, the sensing part made of bearing material is used as the shock absorber of the saw blade at the same time, which has two advantages. Made of many materials.

Another particularly suitable embodiment of the present invention envisages placing the ripstop in a housing that can be detachably attached to the chainsaw so that if a part of the ripstop becomes worn, it can be easily replaced .

It is further envisaged that the positioning means take the form of an arm, which is pivotable about an axis extending parallel to the axis of the chainsaw, or adjustable along an arc lying on a plane extending perpendicular to this axis. In this structure, it is also possible to take the following form, that is, the anti-splitting device has a cylindrical cross-section, is rotatable about its axis and is formed of a cuttable material. From the concept of the invention it is particularly beneficial if the pivot axis of the arm is spaced from the axis of the saw blade 14 by a distance which corresponds to the radius of the cylindrical cut-stop.

The axis of the arm is set directly above the axis of the saw blade and together with the axis of the saw blade defines a plane of extension perpendicular to the surface of the workpiece, thereby ensuring that the anti-cutting device is always located where the teeth of the saw blade emerge from the workpiece. The advantage of the cut protection having a cylindrical recess opening towards the saw blade is that the wear of the working face of the cut protection is uniform. Finally, precautions have been taken with regard to the radial appearance of the cut guard which slopes towards the saw blade. As a result, operationally correct contact of the cut protection device is ensured even when the saw blade is at an acute angle to the surface of the workpiece.

Some illustrative embodiments of the invention are detailed diagrammatically as follows:

Figure 1 shows a part of a chainsaw with an anti-split device in a top view;

Figure 2 shows a chainsaw with another anti-cut device;

Figure 3 shows a chainsaw whose cut protection device is pivotally mounted;

Fig. 4 shows the electric saw shown in Fig. 3 seen from the direction of arrow IV, and the saw is in cutting operation;

Figure 5 shows the chainsaw shown in Figure 4 prior to a cutting operation;

Figure 6 shows a chainsaw with a cut guard, the cut guard of which is pivotably mounted;

Fig. 7 is a side view of the chainsaw shown in Fig. 6;

Figure 8 shows a saw table with parts of the anti-split device;

Fig. 9 shows a hole saw with an anti-split device in a top view;

Figure 10 is a side view of the keyhole saw shown in Figure 9;

Figure 11 shows the anti-cut device designed as a separate component;

Figure 12 shows the operative engagement of the cut guard shown in Figure 11 with a manual circular saw;

Fig. 13 shows the manual circular saw shown in Fig. 12 seen from the direction of arrow XII;

Figure 14 shows a part of a chainsaw with a positioning device designed as an arm in a side view;

Figure 15 is an end view of the chainsaw shown in Figure 14;

Figures 16 and 17 show a part of a chainsaw with two positioning devices;

Figure 18 shows a chainsaw with a pivotable table and a positioning device.

FIG. 1 shows a chainsaw with a saw blade 10 and a cut guard 16 . The cut guard 16 is operatively engageable with the saw, may abut against a workpiece (not shown) and may be positioned on the side of the saw blade 10 where the side teeth 14 emerge from the workpiece. Formed in the saw table 20 of the electric saw is a saw blade channel 18 in which the saw blade 10 is accommodated for rotation about an axis 24 . The anti-cutting device 16 is designed to be in pressure contact with the exposed teeth 14 of the saw blade. Furthermore, the cut protection device 16 can also be designed in such a way that it can abut against the point 34 on the workpiece on the contact surface defined by the workpiece and the saw table 20 , or it can project from the saw table 20 to the workpiece. The cut protection device 16 is placed in the housing 50 and its radial position is defined by the screws 36 and 38 . Since there is no positive engagement between the set screws 36 , 38 and the housing 50 , a spring member 44 is provided which applies pressure to the housing 50 .

The anti-splitting device 16 also has a sensor 32 that is in pressure contact with the saw blade body 30 and a component 34 that is in pressure contact with the teeth 14 of the saw blade and is designed as an anti-splitting component. The sensing element 32 and the anti-cutting component 34 are adjustable in the axial direction of the saw blade 24 so that they can be set. The cut-off protection element 34 is adjustable relative to the sensor element 32 which is designed as a stop means for the cut-off protection element 34 . At the initial position, that is, before the anti-splitting device operates, a gap 3 is formed between the sensing element 32 and the anti-splitting component 34 . If the electric saw is turned on at this time, the teeth 14 of the saw blade are then actively engaged with the anti-split component 34 made of a cuttable material, so that the gap 31 becomes extremely small. In this location, the anti-crack element bears on the sensor element 32 . In practice, when the sensing member 32 which is in pressure contact with the flat portion of the saw blade body 30 is worn, the anti-cut member 34 is subject to further wear. Although the sensing element 32 and the anti-splitting component 34 are in pressure contact with the spring elements 26 and 28 respectively, the spring element 28 only presses the anti-splitting component 34 against the sensing element 32 . In addition, the sensing member 32 and the anti-splitting member 34 can be adjusted with the adjustment screws 40 and 42, and this adjustment is carried out with respect to the shaft 24. Figure 2 shows both sides of the saw blade 10, each cooperating with a cut protection device. In this configuration, the individual components of the ripstop are nearly mirror image designs. The sensing element 32', the anti-cut part 34' and the spring part 26' correspond approximately to the corresponding parts of another anti-cut device.

FIGS. 3 to 5 show the cut protection device 316 pivotable about the axis 25 via an articulated lever 48 and an articulated head 46 . The axis 25 is parallel to the axis 24 of the saw blade 10 . In this way, the cut guard 316 can pivot in the direction of rotation of the saw blade 10 . The sensing element 32 and the cut-proof component 34 are placed in the housing 50 . As shown in FIGS. 4 and 5 , the anti-splitting member 34 is further forward and has an inclined stop surface 52 . The articulated arm 48 cooperates with the pressure spring 54 to press the anti-splitting device 316 against the workpiece.

FIGS. 6 and 7 show a manual circular saw with a cut guard 616 housed in a guard case 650 with a sensor 632 and a cut guard 634 . The pillar 601 which is in pressure contact with the spring element 626 and supports the sensing element 632 and the anti-split component 634 is also placed in the housing 650 . The anti-split component 634 can rotate relative to the pillar 601 in an articulated manner and can pivot around the shaft 51 , while the sensing element 632 can be set with the adjusting screw 40 . The anti-split member 634 is rotatable about the longitudinal axis of the hinge arm 47 and pivotable in the direction indicated by the arrow. The articulated arm 47 cooperates with a spring element 49 to press the anti-splitting component 634 against the workpiece 12 .

FIG. 8 shows a saw table 20 having a saw blade channel 18 and a guard box 50 . The anti-cut device 16 that has sensor 32 and anti-cut part 34 can be placed in the protective case 50, just these two parts are placed in another protective case 2 earlier, like this, the anti-cut device There is no difficulty in inserting into and/or removing from the protective case 50 .

Figures 9 and 10 show that the anti-split device can also be used in a keyhole saw, and the saw blade 914 reciprocates vertically.

11 to 13 show a cut guard 1116 which is used as an accessory for a manual circular saw and a keyhole saw and is therefore designed as a separate part. This cut-stop device 1116 includes a plug member 1118 with two cut-stop members 1120 and 1122 respectively positioned on either side of the saw blade 10, the two cut-stop members being constructed of a cuttable material. , That is to say, it is made of a material whose hardness is lower than that of the teeth of the chainsaw. Anti-splitting members 1120 and 1122, where they contact saw blade 10, have sensing members 1132 and 1134 that are harder than anti-splitting members 1120 and 1122 and are preferably constructed of a bearing material.

Another feature of the cut-resistant members 1120 and 1122 is that they articulately engage the plug member 1118 at locations 1124 and 1126 . The ends of the anti-cut components 1120 and 1122 away from the sensing elements 1132 and 1134 cooperate with the compression spring 1130 to press the sensing elements 1132 and 1134 against the saw blade 10 . The nature of the articulated connection is based in particular on the fact that, due to the gap 1110 between the anti-splitting elements 1120 and 1122 ; the two anti-severing elements can therefore be brought into pressure contact with the saw blade 10 independently of each other. In this way, they are actually in variable pressure contact with the saw blade 10 and so follow the lateral movement of the saw blade 10 . The chainsaw has a socket 1136 with a tension screw 1140 for securing the plug 1118 . Another characteristic of the anti-split device 1116 is that, because its thickness is approximately consistent with the thickness of the guide rail, it can preferably also be actively engaged with the guide rail of the chainsaw, so that the anti-split device 1116 can be pressed against the workpiece tightly, while Between the teeth 14 and the cut-off protection elements 1120 , 1122 no interspaces are formed which could have a major influence on the formation of splinters in the region of the upper edge of the workpiece.

14 to 16 show a cylindrical cut-resistant member 634 supported by a positioning device 3 having an arm 7 . The arm 7 has two elbows and is articulated directly above the shaft 24 of the saw blade 14 at a distance r from the shaft 24 which is the same as the radius r of the anti-splitting member 634 . This ensures that the anti-splitting member 634 is always pressed against the workpiece 12 exactly where the teeth of the saw blade 14 emerge from the workpiece 12 . When the arm 7 pivots, the supporting point of the anti-splitting component 634 moves along the circular track on the circumference of the saw blade 14 , so that the anti-splitting component 634 can roll on the workpiece 12 . The anti-split part 634 has a cylindrical recess 5 opening towards the saw blade 14, the peripheral surface 6 of which is inclined to the saw blade 14 (see FIGS. 16 and 17). Due to this approach, in case the rip protection part consists of a cuttable material, such as plastic, then the teeth of the saw blade may wear it evenly. In order to minimize wear on part 634, in the illustrative embodiment a sensor element 32 is also provided which consists of a bearing material with good sliding properties. The sensing element can consist of bronze, sintered metal or graphite.

The arm 7 cooperates with the tension spring 19 to press the anti-splitting component 634 against the workpiece 12 . Even after adjusting saw table 20 for changing depth of cut, or after pivoting for cutting beveled edges or bevel cuts (see FIGS. 14 the appropriate point of the tooth part. 16 and 17 show the saw blade 14 with the anti-split members 634 on both sides. The anti-split member is supported by arms 7, which are arranged in parallel but independent of each other.

However, as shown in the embodiment shown in Figure 18, the anti-cut part 34 can also be designed into a block shape and be articulated with the positioning device designed as a rod 11, installed on the outer cover 8 or the guard cover of the manual circular saw. on axis 13. The axes 13, 15 and 24 of the joints run parallel to one another. The surface of the anti-cut part 34 contacting the saw blade 14 will obviously be larger than the surface swept by the teeth of the saw blade 14, preferably at least about 4 times larger. position, the teeth always remain in contact with the anti-cut part 34; even when the saw table 20 pivots around the axis 9, the anti-cut part 34 engages the toothless side of the saw blade 14 as described in the previous illustrative embodiment The supported sensor 32. For this purpose, the sensing element 32 is mounted on the end of the anti-splitting part 34 which is close to the shaft but remote from the saw table 20, or is mounted on a corresponding bracket.

The anti-split member 34 can move along its supporting surface in the groove of the saw table 20, or is pressed towards the workpiece by the spring 54' supported on the protective box 8, so it is always straight. For example, the rod 11 can be used to press the anti-split member 34 against the saw blade 14. In this application, the rod 11 is designed to be elastic and mounted on the housing 8 so that the saw blade 14 is prestressed. Of course, the positioning devices 3 and 11 are also configured in pairs, one left and one right, and close to the saw blade 14, so that the saw blade is elastically acted on by an anti-split member on each side.

The positioning device can of course also be designed differently. For example, in particular a control cam is conceivable which extends parallel to the saw blade and is guided along a control arm which bears the deflection protection device 34 at one end. In this case, the size of the control cam and arm should be such that the deflection guard is in its necessary position relative to the teeth emerging from the workpiece when the table is adjusted. Another possible embodiment proposes the use of a prestressed cable, by pulling on which the deflection protection can be set.

In summary, the proposed cut guard or deflection protection can be applied to manual circular saws, keyhole saws, stationary saws, and even other industrial chainsaws. Since the ripstop can be assembled from separate parts and then joined to a manual circular saw, it is inexpensive to produce. Since the material is prevented from breaking at the saw teeth, there is no need for saw table parallel guides. The integrated deflection protection with the sensor element is elastically guided on the saw blade so that no gaps form between the saw teeth and the deflection protection. However, the sensing element can also be adjusted as required.

Another advantage of the proposed cut-off protection device is that it can be attached under the saw table, so that cuts are prevented even if the surface of the workpiece is uneven. In such an arrangement it is advantageous to resiliently attach the cut guard to the chainsaw. Both the sensing part and the cut-proof part are molded parts, which are easy to replace and low in cost.

Claims (19)

1. An anti-split device for a saw blade electric saw, the device can be placed on the workpiece and can be mounted on the side of the saw blade and in pressure contact with the saw blade where the teeth of the saw blade emerge from the workpiece, its features There is at least one positioning device (3, 11), which can be connected to the chainsaw and supports the anti-cutting device (34, 634) so that the anti-cutting device can change the cutting depth and/or the saw blade (14) When the tilt angle changes, it can still be placed in the correct operating position. 2. Anti-split device according to claim 1, characterized in that the anti-split device (16) can be adjusted radially relative to the saw blade (10), so that it can be set. 3. The anti-split device according to claim 1 or 2, characterized in that the pressure of the anti-split device (16, 1116) acting on the saw blade (10) can be set. 4. The anti-split device according to claim 3, characterized in that, the anti-split device (16, 1116) has a sensor (32, 1132, 1134) in pressure contact with the strip body (30) of the saw blade (10) , the pressure sensor supports a component (34) that is in pressure contact with the teeth (14) of the saw blade and is designed as a cut-proof component. 5. The anti-split device according to claim 4, characterized in that, the sensor (32, 1132, 1134) and the anti-split component (34) are adjustable in the axial direction of the saw blade (24). 6. anti-splitting device as claimed in claim 5, is characterized in that, anti-splitting part (34) can be adjusted relative to sensor (32), and this sensing part (32) is designed as anti-splitting part ( 34) stop device. 7. anti-split device as claimed in claim 6, is characterized in that, this sensor (32,1132,1134) is made of bearing material, and anti-split device (34) then is than the tooth (14 of saw blade) by hardness. ) is composed of a material with low hardness. 8. The anti-split device according to claim 7, characterized in that, the anti-split device (1116) comprises a plug (1118), which can be detachably connected to the electric saw and has two Anti-splitting components (1120, 1122), the two anti-splitting components can be installed on both sides of the saw blade (18), and can be in pressure contact with the saw blade (10). 9. The anti-split device according to claim 8, characterized in that, the anti-split components (1120, 1122) are connected to the plug (1118) by a joint. 10. The anti-split device according to claim 9, characterized in that, the anti-split component (1120, 1122) cooperates with at least one spring element (1130) so that the anti-split component is in pressure contact with the saw blade (10) . 11. The anti-splitting device according to claim 10, characterized in that, the anti-splitting component (1120, 1122) is equipped with a sensor (1132, 1134) at a position in contact with the saw blade (10). 12. The anti-sundering device of claim 11, wherein the anti-severing member (1120, 1122) is a progressively offset member made of a cuttable material. 13. The anti-split device according to claim 12, characterized in that, the anti-split device (16) can be jointed to the chainsaw in a articulated manner, and can rotate around the axis (24) of the saw blade (10), or around a parallel axis. An axis (25) extending from the axis (24) pivots. 14. Anti-split device according to claim 13, characterized in that the positioning device (3, 11) has the shape of an arm which can be extended around an axis (2) parallel to the axis (24) of the saw blade (14) , 16) pivots, or is adjustable along an arc lying on a plane perpendicular to the axis. 15. Anti-split device according to claim 14, characterized in that the anti-split device (634) has a cylindrical cross-sectional shape, is rotatable around its axis (4), and is composed of a cuttable material. 16. The cut-stop device according to claim 15, characterized in that the pivot axis (2) of the arm is spaced from the axis (24) of the saw blade (14) by a distance from the cylinder cut-stop device (634) have the same radius. 17. Anti-split device as claimed in claim 16, characterized in that the axis (2) of the arm (3) is set directly above the axis (24) of the saw blade (14), and it is defined together with the axis (24) An extension plane perpendicular to the surface of the workpiece. 18. Anti-split device according to claim 17, characterized in that the anti-split device (634) has a cylindrical recess (5) opening towards the saw blade (14). 19. The cut protection device according to claim 18, characterized in that the radial outer face (15) of the cut protection device (634) is inclined towards the saw blade (14).

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