JPH11197067A - Suction tool for floor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety by preventing a rotating brush from rotating under a condition where a suction tool is tilted up from a face to be cleaned. SOLUTION: A suction tool main body 1 with a suction hole 7 on its underside, a rotating brush storing room 8 formed in this suction tool main body 1 and a rotating brush 11 facing the suction hole 7 and being freely rtotatably stored in the rotating brush storing room 8 are provided and an air intake path for taking open air into the rotating brush storing room 8 is formed and guides for guiding the open air sucked from this air intake path to a brush body and blades of the rotating brush 11 are formed and a cut part for venting (a cut recessed part 7b) is formed on the side edge part 7a in the suction direction of the suction hole 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a floor suction tool used in connection with a vacuum cleaner.

[0002]

2. Description of the Related Art Heretofore, as a floor suction tool of this type, there has been known a suction tool which rotatably supports a rotary brush on a suction tool body and drives the rotary brush to rotate by an electric motor or a turbine.

However, when the rotating brush is driven to rotate by an electric motor, the electric motor is heavy, the handleability at the time of cleaning operation is poor, the number of parts increases, the assembly workability is poor, and the cost is high. There were drawbacks.

[0004] When the rotary brush is driven to rotate by a turbine, the turbine is disposed in a turbine chamber formed in a suction passage from a suction port to a cleaner body, and is rotated by air sucked together with dust. Due to the configuration, there is a problem that dust is clogged in the turbine due to long-term use, and the turbine does not rotate properly.

Therefore, in order to solve the above-mentioned drawback, turbines are arranged at both ends of a rotating brush in Japanese Patent Application Laid-Open No. 9-28630 (A47L9 / 04) or the like, and external clean air is supplied to the turbines. , And suction the air into a vacuum cleaner together with the air sucked from a suction port.

[0006]

However, in this configuration, a turbine is required, the number of parts increases, and a space for arranging the turbine is required, and dust is collected from below the turbine chamber in which the turbine is stored. There has been a problem that suction cannot be performed and dust or the like is left unsucked.

Accordingly, the present applicant has filed Japanese Patent Application No. 9-2644.
No. 71 proposed a floor suction device that forms a guide for guiding outside air to a blade or a brush body of a rotating brush and receives the outside air with the blade or the brush body to rotate the rotating brush.

However, since the floor suction device has a structure in which the suctioned outside air is received by a blade or a brush body and is rotated, even if the suction device is lifted from the surface to be cleaned, the suction device does not have a suction port. In some cases, the suction air is received by a blade or a brush, and the rotating brush rotates at a low speed. If the rotating brush is rotating with the suction tool lifted from the surface to be cleaned in this way, even if it is rotated at a low speed that does not cause injury even if you actually touch it,
There was a problem with safety.

Accordingly, the present invention has been made to solve such a problem, and the rotating brush is prevented from rotating when the suction tool is lifted from the surface to be cleaned, thereby improving safety. It is an object of the present invention to provide an intended floor suction tool.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a suction tool main body having a suction port on a lower surface, a rotary brush storage chamber formed in the suction tool main body, and A rotary brush rotatably housed in the rotary brush storage chamber facing the suction port, wherein the suction tool main body forms an intake path for taking in outside air into the rotary brush storage chamber, and suction from the intake path. A guide for guiding the outside air to the blade of the rotating brush is formed, and a ventilation suction portion is formed on a side edge of the suction port in the suction direction.

A suction tool main body having a suction port on a lower surface, a rotary brush storage chamber formed in the suction tool main body, and a rotation rotatably stored in the rotary brush storage chamber facing the suction port. A brush, and the suction tool main body has an intake path for taking in outside air into the rotary brush storage chamber, and a guide for guiding the external air sucked from the intake path to the brush body of the rotary brush. A ventilation suction portion is formed at a suction-direction side edge of the suction port.

A suction tool main body having a suction port on a lower surface, a rotary brush storage chamber formed in the suction tool main body, and a rotary brush storage chamber facing the suction port and disposed at both ends. A rotating brush that is driven to rotate by sucking outside air to the turbine, and a ventilation suction portion is formed at a suction-direction side edge of the suction port.

[0013] Further, the ventilating suction portion is formed by forming a cutout recess having a width corresponding to the suction passage at a position corresponding to the suction passage to the cleaner body at a side edge of the suction port in the suction direction. It is characterized by the following.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS.

As shown in FIG. 2 and the like, the suction tool main body 1 of the present embodiment comprises an upper case 2, a lower case 3, a lid 4 detachably mounted on the upper case 2 and the lower case 3, It comprises a rotating tube 5 rotatably supported in the vertical direction between the cases 2 and 3, and a joint tube 6 rotatably supported in the circumferential direction of the rotating tube 5.

On the bottom surface of the suction tool main body 1, a suction port 7 is formed over substantially the entire width in the longitudinal direction. Inside the suction tool main body 1, a substantially cylindrical rotating brush storage chamber 8 is formed. A notch recess (vent) having a width corresponding to the suction passage 5a is formed at a position corresponding to the suction passage 5a to the cleaner body formed in the rotary pipe 5 at a suction direction side edge 7a of the suction port 7. Suction portion) 7b.

Further, on both longitudinal sides of the suction tool main body 1,
A cylindrical shaft support 9 for rotatably supporting a front wheel 27 described later is formed. A partition rib (not shown) that stands upright from the lower case 3 and hangs down from the lid pair 4 is located inside the two shaft supports 9, and connects the shaft support 9 and the rotating brush storage chamber 8 to each other. It is partitioned to prevent outside air from being sucked into the rotating brush storage chamber 8 through the cylindrical shaft support 9.

A rotating brush 11 is rotatably accommodated in the rotating brush storage chamber 8 so as to face the suction port 7. Note that no turbine is provided at both ends of the rotating brush 11, and the rotating brush 11 is driven to rotate by a configuration described later.

As shown in FIG. 2, the rotating brush 11 has a core 12 and a pair of brushes 1 mounted by inserting a base 14 into a spiral groove 13 formed in the core 12.
5 and a pair of blades 16 which are also mounted by inserting the base 18 into the spiral groove 13 of the core 12.

The core 12 is formed by extruding aluminum, and the four grooves 13 arranged at equal intervals are formed in a spiral shape such that they are shifted from each other by about 90 °. Therefore, the brush body 15 and the blade 16 inserted into these grooves 13 also have a similar spiral shape. Further, the pair of brush bodies 15 and the blades 16 are arranged so that the same kind of brush bodies and the blades are symmetrically located at 180 ° apart from each other, so that the balance at the time of rotation is improved and the rotation is smooth. .

The brush body 15 is formed of nylon or polyethylene resin, and the length up to the tip is such that the tip reaches the tip of the carpet to be sucked when cleaning a carpet with long hair. , Are formed shorter than the blade 16 described below.

On the other hand, the blade 16 is made of a cloth 17 having a fine weave that does not allow air to pass through, a base 18 formed by molding a synthetic resin at one end of the cloth 17, and the cloth 17. Brush-like body 1 sewn to the other end (tip) of the brush
9. The cloth-like body 1 is formed by forming a base 18 molded with a synthetic resin on the cloth-like body 17.
7 is deformed so as to undulate, and further, a brush-like body 19 is sewn to the tip of the cloth-like body 17 so that the cloth-like body 1
7 is bent to one side as if pulled. The blade 16 is mounted on the core body 12 so as to be curved backward with respect to the rotation direction of the rotating brush 11 (counterclockwise direction in FIG. 2).

When the rotation of the rotating brush 11 is stopped or at a low speed, the blade 16 rotates the rotating brush 1.
1 is curved backward with respect to the rotation direction (counterclockwise direction in FIG. 2), but when the rotating brush 11 is in a high-speed rotation state, it is in an upright state as shown in FIG. The brush is formed so that the diameter of the rotation trajectory in the upright state is larger than the diameter of the rotation trajectory of the brush body 15 and also comes into contact with a floor surface such as a flooring. When the rotary brush 11 is stopped, the brush body 15 and the blade 16 are formed so as not to contact the floor surface even when the suction tool main body 1 is placed on the floor surface.

On the other hand, a guide port 20 is formed on the upper surface of the lid 4 over substantially the entire width of the brush body 15 and the blade 16 of the rotary brush 11 in the longitudinal direction. On the front side of the guide port 20, a first rib 21 is formed which serves as a guide for guiding outside air sucked from the guide port 20 to the brush body 15 and the blade 16 of the rotating brush 11. The first rib 21 is formed so as to hang slightly from the rear surface side of the lid 4 to a position closer to the center of rotation than the foremost position of the rotation trajectory of the brush body 15 and the blade 16, and to a position that does not contact the maximum rotation trajectory of the blade 16. Has been extended.

Also, a second rib 22 is formed on the rear side of the guide opening 20 to guide the outside air sucked from the guide opening 20 to the brush body 15 and the blade 16 of the rotating brush 11. The second rib 22 extends from the center of rotation of the rotating brush 11 to the front side and has a distal end bent downward.
A discharge port 23 is formed between the two tips.

The upper part of the discharge port 23 is covered with a cover 24 so that the discharge port 23 is not directly visible from the outside. The cover body 24 is attached to the lid body 4 by locking the front and rear locking claws 25 into the claw holes 25a formed in the upper edge of the first rib 21 and the second rib 22. ing. As shown in FIG. 3, the cover 4 to which the cover 24 is attached can be removed by operating the knobs 4a provided on both sides of the cover 4 outward. Thus, the rotating brush 11 and the like can be maintained.

The above-described guide port 20, first rib 21, and second
An intake path 26 is formed by the ribs 22 and the cover body 24, and the intake path 26 is configured so that the width gradually decreases from the guide port 20 to the discharge port 23.

On the other hand, the front wheel 2 mounted on the shaft support 9
Reference numeral 7 is formed to have substantially the same diameter as the external shape of the suction tool main body 1 formed in a substantially cylindrical shape. On the other hand, the suction tool body 1
A rear wheel 28 having a small diameter is rotatably supported at the rear portion. A suction keeper 29 made of soft rubber or the like is provided before and after the suction port 7.
The suction keeper 29 improves the deep suction force. Further, a bumper 30 made of soft rubber or the like is provided on the front surface of the suction tool main body 1 having a substantially cylindrical shape. The tool body 1 itself can be prevented from being damaged.

When the above-described joint pipe 6 of the suction tool body 1 is connected to a cleaner body (not shown) via a flexible hose and an extension pipe, and the electric blower of the cleaner body is driven, the suction port 7 is opened. Air is sucked. When the suction tool main body 1 is lifted from the surface to be cleaned, the suction resistance from the suction port 7 in which the cutout recess (ventilation suction portion) 7b is formed corresponding to the suction passage 5a of the rotating pipe 5, is small. Most of the air is sucked from the suction port 7, particularly the notch recess 7b.

In this state, since the suction port 7 (particularly, the notch recess 7b) is largely open, the flow velocity of the sucked air is relatively low, and the air sucked from the notch recess 7b The rotating brush 11 does not rotate because it does not hit the brush body 15 or the blade 16 at all.
Accordingly, there is no danger of injury even if a hand or the like touches the rotating brush 11, and there is no danger in appearance, so that safety is remarkably improved.

When cleaning the floor surface such as a flooring or a tatami mat, the clearance between the surface to be cleaned and the suction port 7 is relatively wide, so that the suction resistance from the suction port 7 is relatively small.
, Almost no air is sucked in from the guide port 20. In this state, since the air sucked from between the suction port 7 and the surface to be cleaned has a high flow velocity, the air sucked from the suction port 7 hits the brush body 15 and the blade 16 of the rotating brush 11 and the rotating brush 11
Is rotated counterclockwise in FIG.

In this case, the brush body 15 allows air to pass easily, but since it is formed so as not to be in contact with a floor surface such as a flooring, the brush body 15 functions to rotate the rotary brush 11 to some extent. On the other hand, since the blade 16 is curved rearward in the rotation direction of the rotating brush 11 as described above when the rotating brush 11 is in the rotation stopped state or in the low-speed rotating state, the air sucked from the suction port 7 is The rotating brush 11 rotates efficiently because the air is difficult to pass through using the cloth 17 which is easy to receive and has a fine texture.

When the rotating brush 11 rotates at a high speed, the blade 16 is erected by the centrifugal force as shown in FIG. In the upright state of the blade 16, the brush-like body 19 sewn to the tip of the cloth-like body 17 comes into contact with the floor surface or the tatami mat surface, so that wiping cleaning or polishing cleaning can be performed. Blade 1
6 uses the easily deformable cloth-like body 17, so that even if it touches the floor surface or the tatami surface, it does not damage the floor surface or the tatami surface.

On the other hand, when cleaning the surface to be cleaned such as a carpet or the like, the suction port 7 is covered by the surface to be cleaned with hairs, the suction resistance from the suction port 7 increases, and the suction port 7 is sucked from the guide port 20. The outside air volume increases. The discharge port 23 has an extremely small opening area as compared with the suction port 7, so that the discharge port 2
The air sucked from 3 collides with the brush body 15 and the blade 16 of the rotating brush 11 at a higher flow rate than the above-described suction port 7, and rotates the rotating brush 11 counterclockwise in FIG. When the rotating brush 11 rotates, dust such as lint on the surface to be cleaned, such as a carpet, is beaten out by the brush body 15 and the blade 16, is scraped off, and is sucked into the cleaner body.

Here, the first position located in front of the discharge port 23 is
As described above, the rib 21 is used for the brush body 15
6 is formed so as to hang slightly near the center of rotation from the forefront position of the rotation locus of 6, so that the outside air sucked from the discharge port 23 goes around the front of the rotary brush 11 without colliding with the brush body 15 or the blade 16. Thus, the rotating brush 11 can be efficiently and rotationally driven.

Similarly, the second port located behind the discharge port 23
The ribs 22 also extend from the center of rotation of the rotating brush 11 to the front side, and the tips are bent downward.
6 can be prevented from being directly sucked into the rotating tube 5 by passing above the rotating brush 11 without colliding with the rotating brush 6, and can be reliably guided to the brush body 15 and the blade 16, so that the rotating brush 11 can be efficiently moved. It can be driven to rotate.

The outside air from the guide port 20 is discharged to the discharge port 23.
Is configured so that the width gradually decreases toward the discharge port 23, so that the generation of noise due to a change in the area of the ventilation path is reduced, and the brush body 15 and the blade 16 The rotational efficiency of the rotating brush 11 can be improved by increasing the flow velocity of the outside air colliding with the rotating brush 11.

Further, since the rotary brush storage chamber 8 is formed in a substantially cylindrical shape, the first rib 21 and the second rib 2 are formed.
Since the outside air that has been guided by 2 and collides with the brush body 15 and the blade 16 is not diverged but smoothly wrapped around and continues to apply a rotational force, the rotating brush 11 can be driven to rotate more efficiently.

Further, since the suction passage 26 has the guide port 20 on the upper surface of the suction tool main body 1, even when cleaning the wall or the like, the suction is not blocked by the wall or the like. Rotational force can always be applied to the blade 15 and the blade 16 at a good flow rate.

As a secondary effect, the guide port 20
By sucking the outside air from, the suction tool main body 1 can be prevented from being excessively sucked to the surface to be cleaned, and the mobility of the suction tool main body 1 can be improved.

When cleaning a carpet or the like as described above,
The surface to be cleaned having hairs acts as a resistance, and the rotation speed of the rotating brush 11 decreases. However, when the rotation speed of the rotating brush 11 decreases, the blade 16 gradually stops at a stop due to a decrease in centrifugal force. It curves backward with respect to the direction of rotation so as to restore its shape, the contact resistance with the surface to be cleaned is reduced, and the number of rotations is increased. By repeating this operation, the rotation speed of the rotating brush 11 is maintained substantially constant.

That is, since the blade 16 is formed by sewing the brush-like body 19 to the cloth-like body 17, the blade 16 can be configured to be easily bent, and the brush-like body 19 is weighted by centrifugal force. The blade 16 can be easily erected, and the blade 16 can be erected and curved even by a slight change in the number of revolutions of the rotating brush 11, so that the number of revolutions of the rotating brush 11 can be maintained substantially constant.

When the suction tool is lifted from the surface to be cleaned while cleaning the floor surface such as the flooring or the carpet described above, most of the outside air which has been sucked from the suction port 7 and the guide port 20 until then is removed from the suction port 7. The rotating brush 11 stops sucking rapidly because the fluid is sucked from the notch recess 7b, and the flow velocity is reduced and the rotating brush 11 does not hit the brush body 15 or the blade 16 of the rotating brush 11. Therefore, as described above, there is no danger of injury even if the hand or the like touches the rotating brush 11, and there is no danger in appearance, so that the safety is significantly improved in this case as well.

Further, since the rotary brush 11 faces the suction port 7 and the clearance between the rotary brush 11 and the edge of the suction port 7 is small, a large amount of dust such as paper debris is removed from the rotary brush 11 and the edge of the suction port 7. However, by forming the above-described cutout recesses 7b, even large dust such as paper waste can be easily sucked without being caught by the rotating brush 11.

It is also conceivable to form the cutout recess 7b as described above over substantially the entire width of the suction-direction side edge 7a of the suction port 7, but in this case, the bristle tip of a carpet or the like is drawn from the suction port 7b. 7 A large amount is sucked over the entire width.
Then, this becomes entangled with the brush body 15 and the blade 16 of the rotating brush 11 and becomes a large resistance.
The rotation of No. 1 is not performed well, and the efficiency of collecting dust such as lint is reduced. Therefore, as in the above-described embodiment, the notch recess 7b having a width corresponding to the suction passage 5a is formed at a position corresponding to the suction passage 5a to the cleaner main body formed in the rotating pipe 5, thereby achieving the above-described operation. Since the large amount of ventilation can be ensured without such troubles as described above, the rotating brush 11 can be efficiently prevented from rotating when the suction tool is lifted from the surface to be cleaned.

Further, according to the floor suction tool of the present embodiment,
Without having turbines at both ends of the rotating brush 11,
Since the rotary brush 11 can be efficiently rotated and driven only by the brush body 15 and the blade 16, it is possible to reduce the weight and size of the floor suction tool and to reduce the cost. Further, since there is no turbine at both ends of the rotating brush 11, the suction port 7 can be formed over substantially the entire width of the bottom surface of the suction tool main body 1, so that dust such as lint does not remain.

As described above, the rotary brush 11 is driven to rotate without using the turbine.
1 is configured to be easily rotated as described above, but if configured to be easily rotated, it becomes easy to rotate even when the suction tool is lifted from the surface to be cleaned. It is particularly effective to form the portion 7b so as not to rotate.

In the above-described embodiment, the cutout recess 7b is formed in the side edge 7a of the suction port 7, but the suction port 7 is formed in the same position and the same size opening is formed in the same position as the conventional one. You may do it.

In the above embodiment, the rotating brush 11
Are provided with a pair of brush bodies 15 and blades 16, respectively, that is, a total of four. However, only one of them can be rotated. The number of sheets is not limited to four, but if the number of sheets is increased too much, the interval between them becomes narrower, and the area that the sucked outside air hits becomes smaller. Is best.

Either the brush body 15 or the blade 16 may be a blade made of a non-breathable material having soft elasticity, specifically, a soft polyvinyl chloride (PVC) or a soft rubber (for example, urethane rubber). In this case, the rotational force can be further increased.

Further, in the above embodiment, the guide opening 20 is formed on the upper surface of the lid 4 to provide the air intake passage 26. However, without forming such a guide opening 20, the front part of the suction tool main body 1 can be formed. The gap between the bottom surface and the surface to be cleaned may be wider than the other, and the gap may be used as an intake path. In this case, the suction port 7
The outside air sucked from the front gap at the front edge of the
By forming a guide for guiding the brush body 15 and the blade 16 below the rotation center of the rotating brush 1, the rotating brush 1
1 can be driven to rotate efficiently.

The formation of the cutout recess (venting portion for ventilation) 7b as described above is particularly effective when applied to the rotating brush 11 of this embodiment which does not use a turbine as described above. Even if the invention is applied to a suction tool having turbines at both ends of the brush 11, similar effects can be obtained in terms of safety, which is effective.

[0053]

As described above, according to the present invention, an intake path for taking in outside air into the rotary brush storage chamber is formed in the suction tool main body, and the external air sucked from the intake path is guided to the blade of the rotary brush. On the other hand, by forming a ventilation suction portion on the suction direction side edge of the suction port, most of the air is sucked from the ventilation suction portion when the suction tool is lifted from the surface to be cleaned, The rotating brush does not rotate because it does not hit the rotating brush. Therefore, there is no danger of injury even if a hand or the like touches the rotating brush, and there is no danger in appearance, so that safety is remarkably improved. In addition, since the rotating brush can be driven to rotate without providing turbines at both ends of the rotating brush, it is possible to reduce the weight, size, and cost of the floor suction tool. Further, since there is no turbine at both ends of the rotary brush, the suction port can be formed over substantially the entire width of the bottom surface of the suction tool main body, so that dust such as lint does not remain. In addition, since the turbine is not used, the rotating brush itself needs to be configured to be easily rotated.However, if the rotating brush is configured to be easily rotated, it becomes easy to rotate even when the suction tool is lifted from the surface to be cleaned. It is particularly effective to form a ventilation suction portion to prevent rotation.

In addition, an intake path for taking in outside air into the rotary brush storage chamber is formed in the suction tool main body, and a guide for guiding the external air sucked from the intake path to the brush body of the rotary brush is formed. The same effect as described above can also be obtained by forming a ventilation suction portion on the side edge in the suction direction.

Also, in the floor suction device in which turbines are disposed at both ends of the rotary brush, the suction device is formed in the same manner as described above by forming a ventilation suction portion at the suction-direction side edge of the suction port. In a state where the rotary brush is lifted from the cleaning surface, most of the air is sucked from the ventilation suction portion and does not hit the rotary brush, so that the rotary brush does not rotate. Therefore, there is no danger of injury even if a hand or the like touches the rotating brush, and there is no danger in appearance, so that safety is improved.

Further, the ventilating suction portion has a cutout recess having a width corresponding to the suction passage at a position corresponding to the suction passage to the cleaner body at a side edge of the suction port in the suction direction. By doing so, a large amount of air can be secured without causing the problem that the tip of a carpet or the like is sucked in over the entire width of the rotating brush and the contact resistance increases, so that when the suction tool is lifted from the surface to be cleaned, It is possible to efficiently prevent the rotating brush from rotating.

[Brief description of the drawings]

FIG. 1 is a bottom view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a central portion.

FIG. 3 is also a top view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suction tool main body 4 Lid 5 Rotating pipe 5a Suction passage 7 Suction port 7a Suction side edge 7b Notch recess 8 Rotary brush storage room 11 Rotary brush 15 Brush body 16 Blade 17 Cloth body 19 Brush body 20 Guide port 21 first rib 22 second rib 23 discharge port 26 intake path

Claims (4)

[Claims] 1. A suction tool main body having a suction port on a lower surface, a rotary brush storage chamber formed in the suction tool main body, and a rotation rotatably stored in the rotary brush storage chamber facing the suction port. A suction passage for taking in outside air into the rotating brush storage chamber, and a guide for guiding the outside air sucked from the suction passage to the blades of the rotating brush. A suction tool for floors, wherein a suction part for ventilation is formed at a side edge of a mouth in a suction direction. 2. A suction tool main body having a suction port on a lower surface, a rotary brush storage chamber formed in the suction tool main body, and a rotation rotatably stored in the rotary brush storage chamber facing the suction port. A brush, and the suction tool main body has an intake path for taking in outside air into the rotary brush storage chamber, and a guide for guiding the external air sucked from the intake path to the brush body of the rotary brush. A suction tool for floors, wherein a suction part for ventilation is formed at a side edge of a suction port in a suction direction. 3. A suction tool main body having a suction port on a lower surface, a rotary brush storage chamber formed in the suction tool main body, and housed in the rotary brush storage chamber facing the suction port and disposed at both ends. A suction tool for floors, comprising: a rotating brush, which is driven to rotate by sucking outside air, to a turbine, wherein a suction portion for ventilation is formed at a side edge of the suction port in a suction direction. 4. The suction part for ventilation has a cut-out recess having a width corresponding to the suction passage at a position corresponding to the suction passage to the cleaner body at a side edge of the suction port in the suction direction. The floor suction tool according to any one of claims 1 to 3, characterized in that: