Technical field of the invention This invention refers to a hand saw comprising an elongated blade provided with teeth, and a handle connected to a rear end of the blade by means of a joint, which permits rotation of the blade relative to the handle, between an extended working position and a folded position, including a locking mechanism by means of which the blade position relative to the handle can be locked, where the handle comprises firstly a stiff frame with two side walls connected by a common back and delimiting an elongated forward open first slot, and secondly a tooth protector de- vice with two second side walls connected by a second common back delimiting a second slot, and said tooth protector being slidable between an inactive position and an active position protruding in the longitudinal direction of the handle, where the teeth of the blade can be inserted into both said slots.

Aim and features of the invention A hand saw of the general type mentioned in the introduction is described in the patent application SE 9803675-9 of the applicant. On that saw, the tooth protec- tor device is rotatably movable between its active and inactive positions, which has meant certain disadvantages. Among those, the external similarity between the handle frame and tooth protector, especially their widths, has meant that users in some cases have had difficulties to realise that the two parts of the handle should be folded together after the saw blade has been moved to its working position. In such case the protector device is easily damaged by external force. Another disad- vantage occurs when the hand saw is to be provided with a protruding means to al- low attaching it to a garment-mounted holder as described in the patent publication WO 99/20909 of the applicant, since the tooth protector cannot be provided with any protruding means. Still another disadvantage is that the tooth protector in its ac- tive position always extends equally far from the handle in its direction. This means that saws with different blade lengths require manufacture of different versions of handle and tooth protector.

The present invention aims at further developing the saw described in SE 9803675-9 to reduce the disadvantages mentioned above. According to the inven- tion, this is achieved by the features mentioned in the characterizing part of claim 1.

Some preferred embodiments of the invention are further defined in the dependent claims.

Brief description of the drawings included In the drawings show: Figure 1 shows a lateral view of a saw according to the invention, with a blade moved to its working position for sawing, and with a tooth protector in its active position as an extension of the saw handle, Figure 2 shows a corresponding lateral view with the tooth protector in an inactive position inside the handle, Figure 3 shows a lateral view showing the same saw with the blade in a position folded into the handle and the tooth protector, Figure 4 shows a split perspective view showing three different components of the handle, Figure 5 shows a cross section through the handle and the tooth protector inserted therein, Figure 6 a shows corresponding cross section through the tooth protector alone, Figure 7 shows a cross section through the handle in a region of a locking mecha- nism, Figure 8 a shows corresponding cross section showing a pin component of the lock- ing mechanism separated from the handle.

Detailed description of a preferred embodiment of the invention The saw according to the invention shown in figures 1-3 in various positions comprises a handle 1, a blade 2 and a tooth protector 3. The blade 2 carries teeth 4 forming a line of teeth, which preferably, but not necessarily, is basically straight.

The handle 1 comprises an elongated handgrip or frame 5 and a joint part 6 forming a blunt angle with the handgrip 5. Actual values of the angle between the handgrip 5 and the joint part 6 can be in the region 125 to 150 degrees.

The rear toothless rear end portion of the blade 2 is inserted in an open slot in the joint part 6 and attached to this by a joint 7 which allows rotation of the blade relative to the handle. To lock the blade in a desired position a locking mechanism 8 is provided, shown in detail by figures 7 and 8. These show that the locking mecha- nism comprises a cylindrical pin 9 with a head 10. The pin 9 is located in a bore 11 extending through the joint part 6, at right angle to the slot 12 into which the rear end of the blade is inserted. The pin 9 is provided with two axially adjacent constric- tions 13,14 with different diameters. As shown by figure 4 the rear end portion of the blade 2 is generally semicircular, with four separate arcuate recesses 15,16,17,18.

The diameter of these recesses corresponds in principle to the diameter of the lar- ger constriction 14 of the pin 9. The pin is normally held in an outer end position by a spring 19, where the larger constriction 14 is located in the same plane as the slot 12, where the pin locks the blade in a desired position if it engages with one of the recesses 15-18. When the blade is to be released to be rotated, the pin 9 is pressed into the bore 11 against the force of the spring 19 until the narrower con- striction 13 is located in the plane of the slot 12. That constriction 13 has a diameter small enough in comparison to the depth of the actual recess, to allow rotation of the blade to some other angular position, unhindered by the pin.

The separate recesses 15-18 are separately located along the periphery at predetermined angles. In figures 1 and 2, the pin 9 is engaging a recess 17 where the handgrip 5 of the handle forms an angle about 100 degrees with the blade 2. In the position shown by figure 3, the pin is engaging another recess 18, and the blade 2 is inserted in the handgrip 5 basically parallel to it. The handgrip 5 can also form a blunt angle of about 134 degrees with the blade 2 by making the pin engage a third recess 16. Finally, the handgrip 5 may be put at an upward rearward angle from the blade by making the pin engage a fourth recess 15.

With reference to figures 4-6, these illustrate the characterizing features of the invention. As shown by figure 5, the handgrip part 5 of the handle 1 comprises a stiff frame with two lateral walls 21 connected by a common back 20 and separated

by the slot 12, which is a continuation of the slot in the joint part 6. In the following, this slot will be called the first slot. The tooth protector 3 also comprises two lateral walls 22 connected by a back 23 and delimiting a second slot 24. A characteristic feature of this tooth protector is that it is shaped as a slide located in an elongated cavity 25 within the handgrip 5 part of the handle, with an opening slot 12. This slide 3 is longitudinally displaceable between an inactive position shown with interrupted lines in figure 2, and an active protruding position shown in figures 1 and 3. As is clearly shown in figures 5 and 6, the slide 3 has a generally oval cross section, cor- responding to an oval cross section of the cavity 25.

Figure 4 shows how the handle 1 is composed from two halves 26,27 made from a polymer material. Both these halves are made with flat insides 28 and con- vexly curved outsides, where the flat insides 28 are pressed together when the halves 26,27 are to be united by a suitable method such as gluing or welding. Each half 26,27 is provided with an elongated recess 29 open towards the free lower end of the handgrip. Together, the two recesses 29 in the two halves 26,27 form the cavity 25 mentioned above. At the bottom of each recess is provided a groove 30 ending at a certain distance from each end of the handgrip 5. These grooves coop- erate with two locking elements formed as protrusions 31 located on the outside of the slide 3 close to its inner end. When the slide is pulled towards its active protect- ing position, the locking elements 31 ensure that the slide is retained by the handle without being disengagable.

One side of the outer end portion of the slide 3 is provided with a hinge de- vice 32 of the kind described in WO 99/20909. As known, this hinge device com- prises a generally horseshoe-shaped outer flange 33 and a narrower neck 34 be- tween the flange and the outside of the slide. The hinge device serves to allow con- necting of the saw to a garment-mounted holder clip of the kind described in WO 99/20909, which includes a keyhole-shaped recess into which the hinge device can be introduced in a manner which allows the saw to swing relative to the holder clip, and which allows easy disconnection of the saw from the holder. One of the grip- ping part halves 26 is provided with a cutout 35 to receive the hinge device 32. This cutout 35 is open at the free end of the handgrip and is provided with a retaining bump 36. When the slide is pushed into its inner inactive position in the cavity 25,

the narrow neck 34 of the hinge device 32 enters the recess 35 and is snapped in place by the bump 36 which fits into a pit-like recess 37 in the hinge device. This snap connection thus ensures that the slide is retained in the corresponding cavity when the saw is to be actively used, in a position shown in figure 2. However, the snap connection does not produce a noticeable resistance to pulling the slide out to the actively protecting position according to figures 1 and 3.

Function and advantages of a saw according to the invention.

When the tooth protecting slide (3) is pushed into its inactive position ac- cording to figure 2, it is basically hidden within the handgrip (5), allowing every pro- spective customer to clearly identify the type of tool as a saw. In the pushed-in posi- tion the slide is also well protected against external damage and reliably secured in the handgrip by the snap connection mentioned above.

When the saw after use is to be stored and the tooth protective action of the slide (3) to be activated, the slide is simply pulled out from the handgrip part of the handle by manually pulling the hinge device (32), past the force of the snap connec- tion. The pulling displacement is limited at an outer end position when the protru- sions (31) reach the ends of the two co-operating grooves (30). In this position, the blade (2) can be folded by rotation to the position shown in figure 3, where the tooth line of the blade is inserted into the first slot (12) in the handgrip part as well as into the second slot (24) in the slide. In this folded position the blade is locked by means of a locking mechanism 8, and more precisely by making the pin (9) enter a recess (18). Then the blade cannot be unintentionally swung open from the handle, and the handgrip part together with the slide will provide a reliable protection of and from the sharp teeth of the blade as long as the user does not by intentional manipulation of the locking mechanism (8) release the blade for active use.

One basic advantage of the saw according to the invention is that the slide serving as a tooth protector can be totally hidden within the handle, and can be dis- placed between its active and inactive positions by a simple linear motion. In its po- sition hidden within the handle, the tooth protector is well protected from damage from external forces. Another advantage is that the means needed for connection to a garment-mounted holder, the hinge device 32, can be provided on the sliding

tooth protector itself, rather than on the saw handle, thereby permitting the hinge device to be almost enclosed in the cutout (35) in the handgrip part of the handle, without protruding noticeably on the outside of the handle. Still another advantage of the invention is that slides with varying distance of displacement to the active po- sition can be simply manufactured, by locating the locking protrusions (31) at differ- ent distance from the free end of the slide. This allows identical handle designs and details to be used for blades of different lengths.