| CLAIMS 1. A belt tensioner (10), particularly of the type for retaining loads to bodies of trucks and the like, characterized in that it comprises - a buckle (11) for tensioning the belt (12) provided with a spool (13) for winding one of its ends and with means (14) for locking the rotation of said spool (13) in a direction (A) of unwinding of said belt (12) from said spool (13), - a lever (15), - reversible means (16) for the pivoting of said lever (15) to said buckle (1 1) about a rotation axis (B) that substantially coincides with the axis of said spool (13), - a ratchet device (17) for jointly connecting the rotation of said lever (15) and of said spool (13) at least in one direction (C) of winding of the belt ( 12) on said spool (13), - means (18) for deactivating said locking means (14), provided on said lever (15), said lever (15) being reversibly pivotable, by way of said pivoting means (16), to said buckle (1 1) in a configuration chosen alternately between - a configuration for tensioning the belt (12), in which said ratchet device (17) is in a configuration for winding the belt (12) on said spool (13), said deactivation means (18) being in an ineffective configuration, and - a configuration for loosening the belt (12), in which said ratchet device (17) is in an ineffective configuration and said deactivation means (18) are in a configuration for controlling said locking means (14). 2. The belt tensioner according to claim 1, characterized in that said pivoting means (16) comprise - pivots (19), which during use protrude from a first component of said belt tensioner (10) chosen between said buckle (11) and said lever (15), - seats (20) for the insertion in a rotary manner of said pivots (19), which are provided on a second component of said belt tensioner (10) chosen between said buckle (11) and said lever (15) and different from said first component. 3. The belt tensioner according to claim 2, characterized in that said 5 pivoting means (16) further comprise means for retracting said pivots (19) in receptacles (21) provided in said first component, in contrast with elastic pusher means. 4. The belt tensioner according to claim 3, characterized in that said retraction means comprise secondary levers (22), which are pivoted on said 10 first component and engage a contoured tail (23) of said pivots (19), jackets being provided on said first component to accommodate said pivots (19), which form internally said receptacles (21) and accommodate compression springs (25), which form said elastic pusher means, comprised between the bottom of said jackets and said contoured tail (23) of said pivots (19), in 15 order to contrast their retraction into said jackets (24) by virtue of the action of said secondary levers (22). 5. The belt tensioner according to one or more of the preceding claims, characterized in that said ratchet device (17) comprises - at least one toothed flange (26), with sawtooth teeth (28), jointly 20. connected to said spool (13), and - at least one guillotine (27) for turning said toothed flange (26), which is adapted to engage its teeth (28) and is supported on said lever (15) so that it can slide with a stroke that is at least equal to the height of said teeth (28), 25 said locking means (14) comprising at least one guillotine (29) for locking said toothed flange (26), which is supported on said buckle (1 1) so that it can slide with a stroke that is at least equal to the height of said teeth (28). 6. The belt tensioner according to claim 5, characterized in that said 30 deactivation means (18) comprise at least one cam (30) provided on said lever (15), in said loosening configuration said lever (15) having said cam (30) in an arrangement for engagement with said traction guillotine (27), an arc of relative rotation (C) of said lever (15) with respect to said buckle (11) along said rotation axis (B) being provided, said at least one cam (30) abutting, at said rotation arc (C), against said locking guillotine (29) so as to modulate its sliding on said buckle (1 1) along said stroke, as a function of the angle of said lever (15) with respect to said buckle (1 1). 7. The belt tensioner according to one or more of claims 5 and 6, characterized in that it comprises elastic means for contrasting the spacing of said guillotines from said at least one toothed flange (26). 8. The belt tensioner according to claim 7, characterized in that said elastic contrast means comprise - a cylindrical helical spring (31), which is connected to said buckle (1 1) and to said locking guillotine (29), to contrast the spacing thereof from said at least one toothed flange (26), - a flexing spring (32), which is connected to said lever (15) and to said traction guillotine (27), to contrast the spacing of the latter from said at least one toothed flange (26). 9. The belt tensioner according to one or more of the preceding claims, characterized in that said lever (15) has, at the free end, a connector (33) with a tool for extension of the lever arm (15). |
Technical Field
The present invention relates to a belt tensioner, particularly of the type for retaining loads to bodies of trucks and the like.
Background Art
Nowadays, particularly in the field of road transport, belt tensioners are known for locking loads to bodies of trucks by means of belts.
These belt tensioners comprise, fixed to a first end of a belt, a buckle provided with a spool for winding another end of the belt.
A lever is pivoted in a fixed manner to the buckle, so as to be made to rotate in order to pull the spool in rotation by means of a ratchet device.
The buckle supports an anti-unwinding lock for the spool.
So, to tension the belt, the operator acts on the lever, thus winding the free end of the belt onto the spool.
Vice versa, in order to free the tensioned belt, the operator releases the anti-unwinding lock from the spool, which rotates by virtue of the action of the tension of the belt, thus unwinding it at least until the tension is relaxed.
A drawback of such belt tensioners is that the loosening of the belt occurs suddenly, so inducing a tension impulse which is transmitted all the way to the hook for securing to the truck body, generally making the hook jump out of its coupling seat, to the detriment of the safety of persons who may be present nearby.
Disclosure of the disclosure
The aim of the present invention is to provide a belt tensioner that makes it possible to limit the unwinding of the spool during the loosening of a belt under tension for retaining a load or the like.
Within this aim, an object of the invention is to provide a belt tensioner that enables a synergy of components when a family of belt tensioners is used.
Another object of the invention is to provide a belt tensioner which, in use, is more compact, for the same level of performance, than the belt tensioners which are known today.
A further object of the invention is to propose a belt tensioner that is structurally simple and easy to use, and which can be produced at low cost.
This aim, as well as these and other objects which will become better evident hereinafter, are achieved by a " belt tensioner, particularly of the type for retaining loads to bodies of trucks and the like, characterized in that it comprises
- a buckle for tensioning the belt provided with a spool for winding one of its ends and with means for locking the rotation of said spool in a direction of unwinding of the belt from said spool,
- a lever,
- reversible means for the pivoting of said lever to said buckle about a rotation axis that substantially coincides with the axis of said spool,
- a ratchet device for jointly connecting the rotation of said lever and of said spool at least in one direction of winding of the belt on said spool,
- means for deactivating said locking means, provided on said lever, said lever being reversibly pivotable, by way of said pivoting means, to said buckle in a configuration chosen alternately between
- a configuration for tensioning the belt, in which said ratchet device is in a configuration for winding the belt on said spool, said deactivation means being in an ineffective configuration, and
- a configuration for loosening the belt, in which said ratchet device is in an ineffective configuration and said deactivation means are in a configuration for controlling said locking means.
Brief description of the drawings
Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the belt tensioner according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:
Figure 1 is a partial perspective view of a belt tensioner according to the invention;
Figure 2 is a partially sectional plan view of a belt tensioner according to the invention;
Figure 3 is a transverse sectional view of the components of a belt tensioner, according to the invention;
Figure 4 is an enlarged scale partially sectional view of the belt tensioner according to the invention;
Figures 5 and 6 are enlarged scale side elevation views of a belt tensioner according to the invention.
Ways of carrying out the invention
It should be noted that everything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.
With reference to the figures, the reference numeral 10 generally indicates a belt tensioner, particularly of the type for retaining loads to bodies of trucks and the like, which comprises
- a buckle 11 for tensioning a belt 12 provided with a spool 13 for winding one of its ends and with means 14 for locking the rotation of the spool 13 in a direction A of unwinding of the belt 12 from the spool 13,
- a lever 15,
- reversible means 16 for the pivoting of the lever 15 to the buckle 1 1 about a rotation axis B that substantially coincides with the axis of the spool 13,
- a ratchet device 17 for jointly connecting the rotation of the lever 15 and of the spool 13 at least in one direction C of winding of the belt 12 on the spool 13, - means 18 for deactivating the locking means 14, provided on the lever 15.
The lever 15 is reversibly pivotable, by way of the pivoting means 16, to the buckle 11 in a configuration chosen alternately between
- a configuration for tensioning the belt 12, in which the ratchet device 17 is in a configuration for winding the belt 12 on the spool 13, the deactivation means 18 being in an ineffective configuration, as shown for the purposes of non-limiting example in Figure 4, and
- a configuration for loosening the belt 12, in which the ratchet device 17 is in an ineffective configuration and the deactivation means 18 are in a configuration for controlling the locking means 14, as shown for the purposes of non-limiting example in Figures 5 and 6.
The pivoting means 16 advantageously comprise
- pivots 19, which during use protrude from the lever 15, and
- insertion seats 20 which are adapted to receive the pivots 19 so that they can axially rotate, such seats being provided in the buckle 11.
Moreover, the pivoting means 16 conveniently also comprise means for retracting the pivots 19 in receptacles 21 provided in the lever 15, in contrast with elastic pusher means.
Such retraction means preferably comprise secondary levers 22 which are pivoted on the lever 15 and engage with a contoured tail 23 of the pivots
19.
On the lever 15 there are conveniently jackets 24 for accommodating the pivots 19, which form internally the receptacles 21 and accommodate compression springs 25, which form such elastic pusher means.
The compression springs 25 are conveniently comprised between the bottom of the jackets 24 and the contoured tail 23 of the pivots 19, in order to contrast their retraction into the jackets 24 by virtue of the action of the secondary levers 22.
In general, in alternative and substantially equivalent embodiments of the invention, the pivots can be protruding from the buckle, the accommodation seats being provided in the lever. Moreover, the receptacles can be provided in the buckle, defined internally in jackets, or in an equivalent manner according to the contingent requirements.
Thus, in alternative embodiments of the invention the secondary levers can be substituted in a substantially equivalent manner by button devices or by other equivalent devices.
More specifically, the ratchet device 17 advantageously comprises
- two toothed flanges 26, with sawtooth teeth, jointly connected to the spool 13 and provided at its ends,
- a traction guillotine 27, which is adapted to engage teeth 28 of the toothed flange 26 and to pull it in rotation, and is supported on the lever 15 so that it can slide with a stroke that is at least equal to the height of the teeth 28.
The locking means ' 14 conveniently comprise a locking guillotine 29 which is supported on the buckle 1 1 so that it can slide with a stroke that is at least equal to the height of the teeth 28, and is adapted to lock a rotation of the toothed flange 26 in the direction of unwinding A.
In an equivalent manner, in other embodiments of the invention there can be more than one locking guillotine and more than one traction guillotine, just as, according to the contingent requirements, there can be only one toothed flange which is jointly connected for example to one end of the spool.
Moreover, conveniently the lever 15 is U-shaped and has the pivoting means 16 at its ends, the deactivation means 18 advantageously comprising two cams 30 which are provided on the lever 15, conveniently at such ends.
According to the contingent requirements, in alternative and substantially equivalent embodiments of the invention, there can be only one cam on such lever, for example at only one of its ends.
Thus, in such loosening configuration, the lever 15 conveniently has the cam 30 in an arrangement for engagement with the traction guillotine 27.
In particular, there is advantageously an arc of rotation C, which corresponds to a relative rotation of the lever 15 with respect to the buckle 11 according to the rotation axis B, at which the cams 30 are abutting against the locking guillotine 29 in order to modulate its sliding on the buckle 1 1 along such stroke, as a function of the angle of the lever 15 with respect to the buckle 1 1.
Preferably there are also elastic means for contrasting the spacing of the guillotines 27 and 29 from the toothed flanges 26, which conveniently respectively comprise
- a cylindrical helical spring 31 , which is connected to the buckle 1 1 and to the locking guillotine 29, to contrast the spacing thereof from the toothed flanges 26,
- a helical spring 32, which is connected to the buckle 15 and to the traction guillotine 27, to contrast the spacing thereof from the toothed flanges 26.
The lever 15 advantageously has, moreover, at the free end, a connector 33 with a tool for extension of the lever arm 15.
The use of the belt tensioner according to the invention is as follows.
To tension the belt, the operator associates the lever 15 with the buckle 1 1, first retracting the pivots 19 in the receptacles 21 by means of the secondary levers 22, and then aligning the pivots 19 with the insertion seats 20 and allowing them to penetrate therein by virtue of the action of the compression springs 25.
In this way, for the tensioning of the belt 12, the lever 15 is pivoted to the buckle 11 , so as to be in such tensioning configuration.
With particular reference to Figure 4, by rotating the lever 15 with respect to the buckle 1 1 in the direction of winding B, the traction guillotine 27 engages with the front 28a of a tooth 28 of the toothed flanges 26, thus pulling, in joint rotation, the spool 13 onto which the belt 12 is wound, in order to be brought into tension.
During this rotation, the locking guillotine 29 encounters the backs 28b of the teeth 28, which it skips over by sliding on the buckle 11.
Vice versa, in a rotation of the lever 15 in the unwinding direction A, the toothed flange 26 is locked by the locking guillotine 29 which engages with the front 28a of the teeth 28, while the traction guillotine 27 encounters the backs 28b of the teeth 28 which make it slide on the lever 15 so as to skip over them.
By repeating these rotations in sequence, the belt 12 is tightened to the desired tension.
When the belt 12 is tightened, the operator can separate the lever 15 from the buckle 1 1 by disengaging the pivots 19 from the insertion seats 20, by acting on the secondary levers 22, for example in order to tighten another belt which is coupled to another buckle according to the invention.
So, by using a series of belt tensioners 10 according to the invention, a single lever 15 is sufficient in order to operate on a plurality of buckles 1 1, which greatly improves the simplicity and economy of use.
In order to loosen the belt which is kept tight by a belt tensioner 10, the operator connects the lever 15 to the buckle 1 1 in such loosening configuration, which, unlike the tensioning configuration, has the lever 15 substantially reversed with respect to the buckle 11, such as for example shown in Figures 5 and 6.
So, when the lever 15 is made to rotate in the unwinding direction A with respect to the buckle 11 in angles of the arc of rotation C,
- first the cams 30 engage, with ramped faces 30a, with the locking guillotine 29, making it slide up the front 28a of the tooth 28, in abutment with which it locks the rotation of the spool 13 in the unwinding direction A,
- then, when the locking guillotine 29 surmounts the height of the tooth 28, the spool 13 is then free to turn in the unwinding direction A in order to relax the tension of the belt 12.
Since, during the rotation of the spool 13 to loosen the belt 12, the lever 15 is again made to rotate by the operator in the unwinding direction A, the locking guillotine 29 arrives at and surmounts the crests 30b of the cams 30, returning by virtue of the action of the cylindrical helical spring 31 to lock the toothed flanges 26 by engaging with the front 28a of the teeth 28. .
In this way, in a rotation to loosen the belt 12, generally the spool 13 rotates by an arc that corresponds to the pitch of the teeth 28, thus limiting the loosening impulse of the belt 12 which nowadays, when using known belt tensioners, causes the hooks that fix the belt to the truck body to pop out.
In practice it has been found that the invention fully achieves the intended aim and objects by providing a belt tensioner that makes it possible to limit the unwinding of the spool during the loosening of the belt under tension for retaining a load.
Moreover, a belt tensioner according to the invention enables a synergy of components when using a family of belt tensioners. Indeed, a single lever is sufficient in order to operate the spools of a plurality of buckles.
Also, in use, a belt tensioner according to the invention is more compact, for the same level of performance, than the belt tensioners which are known today. Indeed, in use the buckle alone can be left to hold the belt in place, separating the lever from it.
A belt tensioner according to the invention is also structurally simple, easy to use, and can be made at low cost.
The invention thus conceived is susceptible of numerous modifications and variation, all of which are within the scope of the appended claims. In addition, all the details may be replaced by other technically equivalent elements.
In practice the materials employed, as well as the dimensions and the contingent shapes, may be any according to requirements and to the state of the art.
The disclosures in Italian Patent Application No. PD2009A000331 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, such reference signs have been inserted for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.
Next Patent: ALIGNMENT DEVICE FOR RUN OUT MEASUREMENT APPARATUS