Clamp for inserting a flexible strand into a container to receive the strand through an opening

Description

1. Field of invention

[0001] The application is in the field of installing cables of dimensions small enough to be handled by hand. It concerns in particular a tool for handling a flexible strand in bending, for example a cable or a cable pulling needle, with the aim of inserting the strand into a receptacle which may be a tube, or a storage reel. 2. State of the prior art

[0002] To insert a strand by hand into a receptacle such as a tube or a spool, a person must grasp the strand by hand at a certain distance from the orifice of the receptacle, this distance corresponding to one insertion pitch, exert a certain pressure on the grasped strand in order to prevent it from slipping in the hand, approach the hand to the orifice in order to push the strand pitch into it, and then release the strand in order to reposition the hand at the same distance from the orifice corresponding to one insertion pitch, and so on.

[0003] Inserting a strand into any receptacle is a difficult operation to perform with bare hands, as soon as the strand encounters a little resistance when being inserted into the receptacle, or if the total length of the strand to be inserted is large.

[0004] Pliers exist to facilitate this operation, such as that described by European patent EP0285699, which comprises a handle that wedges a segment of strand into a groove.

[0005] The pressure exerted by the hand must be sufficient to lock the section of strand in the clamp. Since a slip of the strand in the groove is not necessarily perceptible, a person will tend to exert more pressure than necessary to be sure of preventing this slippage, which is tiring over a long period.

[0006] When repeatedly repositioning the clamp along the strand after inserting each step, a spring-loaded mechanism is often necessary to allow easy opening of the clamp.

[0007] US Patent 3,549,128 discloses a clamp sliding in a guide, also having the disadvantages described above. US Patent 1,959,490 also discloses a clamp for pushing and pulling a strand.

[0008] In addition, for efficient insertion, the insertion step must be large, or the movement must be repeated quickly. But if the step is too large, or the movement is too fast, the clamp cannot prevent the strand from bending rather than entering the hole, which may damage or even break the strand.

[0009] One of the aims of the invention is to remedy these drawbacks of the state of the art. 3. Statement of the invention

[0010] The invention improves the situation with the aid of a clamp according to claim 1.

[0011] When the first part of the segment which is housed in the clamp is kept deformed in bending, the strand can no longer slide longitudinally in the clamp. The pressure necessary to block the strand is therefore that sufficient to deform the strand. This necessary pressure is very easy to control visually by the operator, because it corresponds to a displacement of the blocking means. According to the prior art on the contrary, the pressure preventing longitudinal sliding of the strand is a compression of the strand on a segment left rectilinear, that is to say without deforming it, therefore without displacement perceptible to the naked eye of the blocking means between a contact position without applied pressure, and a pressure position.

[0012] Furthermore, since the guide means surrounds the strand on a second part of the segment housed in the clamp, this second part, which is not held by the locking means, is still prevented from bending when the clamp with the locked strand is pushed towards the orifice, even if great resistance is encountered during insertion through the orifice. By positioning the free end of the guide means in contact with the orifice, which amounts to matching the length of the insertion step to the length of the guide means, or in other words, to the length of the part of the strand segment contained by the guide means, the insertion movement carried out step by step can be repeated very quickly by the operator, without fear of bending the strand.

[0013] Finally, since the strand is elastic in bending, it returns to its initial shape, generally rectilinear, as soon as the pressure on the locking means is removed, which allows the strand to slide freely in the housing of the clamp, without a specific mechanism being necessary to release the strand from the locking means, such as a spring. Thus, the clamp can be easily repositioned at its starting point after inserting a pitch of strand, without any particular effort being necessary to loosen the clamp.

[0014] Thanks to the invention, the insertion operation is thus made more efficient.

[0015] According to the invention, the locking means comprises a fixed lower jaw, comprising the first part of the housing, and a movable upper jaw, capable of entering at least partially into the first part of the housing to cover the first part of the housed segment, the upper jaw having a non-rectilinear profile so as to impart a non-rectilinear shape to the first part of the housed segment when the jaws are brought closer to each other.

[0016] To print a non-rectilinear shape to a flexible strand, it is sufficient to apply pressure to the underside and the top at a few contact points arranged alternately under and on the strand. It is understood that by arranging the lower contact points on the lower jaw and the upper points on the upper jaw, a multitude of jaw profiles are possible. For example, a sinusoidal shape has the advantage of distributing the pressure over the lower and upper surfaces of the strand. On the other hand, a sawtooth shape, although it risks damaging the strand due to the concentration on a small number of points of the pressure exerted on the surfaces of the strand, has the advantage of greater simplicity of manufacture.

[0017] According to one aspect of the invention, the locking means is actuated by pressure exerted by a hand enclosing the two jaws.

[0018] To minimize the effort required by the clamp operator, the jaws are sized to fit together in a normal-sized hand, preferably in the palm. Thus, simply squeezing the hand is sufficient to activate the locking means. In addition, the sensitivity of the hand means that the movement of the jaws toward each other is very easily detected. It is therefore easy for the operator, on the one hand, to know when the locking means is activated, and on the other hand, to properly measure the necessary force without tiring.

[0019] By releasing the hand pressure, the jaws move away in a movement detected by the hand's sensitivity. The operator then knows that the strand has become straight again, that it is no longer blocked and that it can therefore slide in the clamp.

[0020] According to one aspect of the invention, the upper jaw can take at least one position distant from the lower jaw, where the housing is open.

[0021] By moving the jaws a little further apart than necessary for the strand to return to its straight shape, the opening of the clamp housing becomes completely free, which allows the strand segment to be removed from the clamp at the end of the insertion operation, or the strand segment to be housed in the clamp at the beginning of the insertion operation.

[0022] According to one aspect of the invention, the upper jaw is connected to the clamp by a hinge.

[0023] Advantageously, a hinge ensures the alignment of the jaws facing each other.

[0024] According to one aspect of the invention, the upper jaw is connected to the clamp by a flexible membrane.

[0025] Advantageously, the membrane and the jaws may form a single piece. For example, this piece may be made of a plastic material with properties such that the jaws are sufficiently hard, and the membrane, being thin, is sufficiently flexible to allow movement of the upper jaw relative to the lower jaw.

[0026] According to one aspect of the invention, the upper jaw fits into the lower jaw in the manner of a piston.

[0027] Advantageously, the upper jaw is a separate part from the rest of the clamp, and no connecting part is required, such as a hinge or a membrane. It acts as a piston in the lower jaw which, with at least part of the opening of the housing, forms the piston sleeve. To prevent the operator from misplacing the detachable upper jaw, it can however be connected to the clamp by a chain or a cord.

[0028] According to one aspect of the invention, the guide means is a guide tube.

[0029] Advantageously, the part of the housing which is not included in the locking means is included in the guide means, which has the shape of a tube. Thus, the length of the clamp which is not occupied by the locking means serves as a guide tube for the clamp.

[0030] According to one aspect of the invention, the outer diameter of the guide tube is adapted so that the tube enters through the orifice of the receptacle.

[0031] Advantageously, the guide tube can slide into the hole in the receptacle. Thus, the insertion pitch of the strand corresponds approximately to the length of the guide tube.

[0032] According to one aspect of the invention, the receptacle is a tube for receiving the strand, and where the inner diameter of the guide tube is adapted so that the receiving tube slides in the guide tube.

[0033] Advantageously, the guide tube is adapted so that the clamp functions to rewind a strand into a receptacle such as, for example, a reel extended by a leader tube serving to facilitate the insertion of the strand into a sheath when it leaves the reel. The leader tube of the reel constitutes the receiving tube of the receptacle in the sense of the invention. After use of the strand as a cable pulling needle in a sheath, for example, the clamp with a guide tube inner diameter thus adapted, i.e. slightly greater than the outer diameter of the receiving tube, is capable of rewinding the strand into this type of receptacle. The insertion pitch of the strand corresponds approximately to the length of the guide tube.

[0034] According to one aspect of the invention, the opening of the housing in its second part is a longitudinal slot in the guide tube, not parallel to the guide tube.

[0035] Advantageously, since the slot is not parallel to the guide tube, it is not parallel to the housing, nor to the housed strand. The housed strand cannot therefore accidentally exit the housing during the step-by-step insertion operation. Only express manipulation by the operator can force the strand to position itself opposite the slot to exit through the opening.

[0036] According to one aspect of the invention, the slot follows a spiral over at least a portion of the length of the guide tube.

[0037] Advantageously, the spiral shape allows one end of the strand to be inserted into the guide tube by rotating the clamp around the strand, without having to deform the strand.

[0038] According to one aspect of the invention, the slot follows a sinusoidal shape over at least a portion of the length of the guide tube.

[0039] Advantageously, the sinusoidal shape, if it is not very pronounced, makes it easy to push one end of the strand into the guide tube by deforming it slightly so that it adopts the shape.

[0040] The invention also relates to a multitude of other shapes suitable for the slot, which are non-parallel to the guide tube.

[0041] The various aspects of the clamp which have just been described can be implemented independently of each other, or, for some, in combination with each other.

[0042] The invention also relates to a method for inserting an elastic strand in bending through an orifice of a receptacle using a clamp conforming to that which has just been described, comprising a step of positioning a segment of strand in a housing of the clamp, and at least one iteration of insertion of a strand pitch comprising the following steps: applying hand pressure to a locking means having the effect of locking the strand in the clamp by deforming a part of the strand segment, bringing one end of a guide means into contact with the orifice of the receptacle, bringing the clamp and the orifice together over a distance corresponding to the effective length of the guide means and the insertion pitch, releasing the pressure on the locking means having the effect of allowing the strand to slide without opening the housing, repositioning by moving the clamp away from the orifice over a distance corresponding to the insertion pitch. 4. Presentation of figures

[0043] Other advantages and characteristics of the invention will appear more clearly on reading the following description of a particular embodiment of the invention, given as a simple illustrative and non-limiting example, and the appended drawings, among which: THE figure 1shows a first view of the clamp, in an open position, according to one aspect of the invention; the figure 2 shows a second view of the clamp, in an open position, according to one aspect of the invention; the figure 3 shows a third view of the clamp, in a closed position, according to one aspect of the invention; the figure 4 shows a fourth axial view of the clamp in an open position, according to one aspect of the invention; Figure 5 shows a view of the clamp according to another embodiment of the invention. 5. Detailed description of at least one embodiment of the invention

[0044] In the following description, examples of several embodiments of the invention are presented according to different aspects, but the invention can be embodied in different forms.

[0045] The term strand is used to designate the threadlike object to be inserted into a receptacle using the clamp according to the invention. The clamp according to the invention can be used for all types of threadlike objects that are elastic in bending. It is understood that the term strand includes, for example, electric cables, optical cables, or cable pulling needles, made of any material, having this mechanical characteristic of elasticity in bending.

[0046] Several views of the same example of pliers, according to a first embodiment of the invention, are presented by the figures 1 , 2 , 3 And 4 , where the references used are the same.

[0047] The clamp 1 is longitudinal in shape and is traversed along its entire length by a housing 2 for a strand, from a first opening of the housing 2 at one end of the clamp to a second opening at the other end. When it is housed in this housing 2, the strand can therefore protrude from both ends.

[0048] Clamp 1 consists of two main aligned parts, both crossed by housing 2: a part comprising a locking means 3, and a part comprising a guiding means 4.

[0049] The guide means 4 has the shape of a tube in the illustrated examples, and is hereinafter called a guide tube. But other embodiments are possible with other shapes for the guide means 4, depending on the type of opening of the receptacle into which the strand is intended to be inserted.

[0050] The locking means 3 consists of two jaws 3a and 3b connected by a hinge 5. This hinge can be replaced by any other means capable of guiding the upper jaw 3b towards the lower jaw 3a. The lower jaw 3a is fixed and integral with the guide tube 4 with which it can form a single piece, while the upper jaw 3b is movable relative to the rest of the clamp 1.

[0051] The part of the housing 2a located in the locking means 3 is in the lower jaw 3a, and comprises an opening facing the upper jaw 3b.

[0052] This opening of the housing 2 extends in the form of a slot 6, over the entire length of the part of the housing 2b located in the guide tube 4.

[0053] Through this opening, an operator can easily place a flexible strand in bending in the housing 2. The strand, once housed, can slide in the housing without coming out. Indeed, in the locking means 3, it is sufficient to bring the upper jaw 3b closer to the lower jaw 3a to close the opening of the housing 2 in its part 2a. In the guide tube 4, a particularity of the slot 6 is that it is not parallel to the housing 2b. The strand, which is parallel to the housing 2a once it has been inserted by the operator through the slot 6 by slightly deforming it, will therefore no longer be able to come out, except by a reverse operation by the operator involving a similar deformation. The slot 6 can be rectilinear without being parallel, for example adopting the form of a slight spiral starting from the opening of the part 2a at its junction with the part 2b of the housing 2, to join the free end of the guide tube 4 by turning around.The slot 6 can also be sinusoidal without rotating around the guide tube 4, as shown in . figure 2 .

[0054] Once the strand is housed in the clamp, it can slide as long as the locking means is only partially closed, that is to say as long as the jaws 3a and 3b are sufficiently far from each other so that the housing 2 remains rectilinear over its entire length, including in its part 2a. figures 2 And 4 illustrate such a position of the partially closed jaws. In order to control the closing of the locking means 3, the operator places the two jaws 3a and 3b in the palm of his hand. In their partially or fully closed positions, the jaws adopt a substantially cylindrical shape, ergonomically adapted to one-handed operation. The figure 3 clearly illustrates this cylindrical shape of the locking means 3 of the clamp 1, when it is in the closed position.

[0055] When the operator completely closes the locking means 3, that is to say when he brings the two jaws together as close as possible by squeezing his hand, the strand is blocked and can no longer slide, because the housing 2 in which it is housed is no longer rectilinear. Indeed, the contact surface 7 of the upper jaw 3b with the strand has a non-rectilinear profile which pushes a segment of the strand to the bottom of the lower jaw 3a, deforming it in bending. In this embodiment, the profile is sinusoidal but other shapes are possible, such as for example saw teeth. It is preferable but not obligatory that the profile of the contact surface of the lower jaw 3a is identical, so that the two jaws touch the strand on the deformed segment, which has the advantage of increasing the locking force of the strand in the clamp 1 in the closed position.Another way to increase the locking force is to increase the grip of the contact surface of at least one of the jaws, by a suitable material, such as rubber for example.

[0056] When the operator releases his hand, the jaws become free to move away from each other again. The elastic force of the strand tends to make it return to its straight shape, which has the effect of pushing the upper jaw 3b away from the lower jaw 3a. The housing 2 becomes straight again over its entire length, including its part 2a, and the strand can slide again in the clamp.

[0057] The operator can thus alternate very quickly between a position where the strand is blocked in the clamp, and a position where it slides freely, simply by holding the clamp locking means in the palm of the hand, and tightening or loosening the clamp without letting go, which is one of the easiest and least tiring muscular movements for the human body.

[0058] Thanks to the guide tube 4, it becomes very easy to insert the strand into a receptacle, by coordinating the alternating movement of tightening and loosening of the palm of the hand with a back and forth movement towards the orifice of the receptacle.

[0059] Indeed, the tubular shape of the guide means 4 allows the clamp 1 to slide relative to the orifice of the receptacle, which prevents a part of the strand located between the clamp and the receptacle from being exposed to the air when the strand is pushed towards the receptacle, in which case this part of the strand would risk bending or even breaking.

[0060] There are at least two variants of embodiment of the guide tube 4, depending on whether the guide tube 4 enters the receptacle (first variant), or whether the receptacle enters the guide tube 4 (second variant). In the second variant, the receptacle is also a tube, called an insertion tube to distinguish it from the guide tube. An insertion tube is for example a sheath intended to receive a cable if the strand is a cable, or a cable pulling needle starter tube, if the strand is a needle.

[0061] In the first variant, the outer diameter of the guide tube 4 must be slightly smaller than that of the receptacle orifice in order to slide easily into it.

[0062] In the second variant, the inner diameter of the guide tube 4, i.e. the inner diameter of the part 2b of the housing 2 which is in the guide tube, must be slightly larger than the outer diameter of the insertion tube, so that the latter slides easily therein.

[0063] For these two variants, the step-by-step insertion method is similar. An insertion step corresponds to the length of the sliding movement of the guide tube 4 in the orifice of the receptacle, or the sliding movement of the orifice of the insertion tube in the guide tube 4, depending on the variant. It is understood that the length of this insertion step can therefore reach the length of the guide tube 4.

[0064] After having housed the strand in the housing 2 of the clamp 1 by opening and then closing the locking means 3, the operator grasps the locking means 3 with the palm of his hand and positions the free end of the guide tube 4 in the orifice of the receptacle, or he positions the orifice of the insertion tube in the free end of the guide tube 4, depending on the variant.

[0065] He then performs a back and forth movement along the length of the insertion pitch, tightening the palm towards the orifice and loosening the palm in the opposite direction. This gesture is very similar to that applied to a bicycle pump to inflate a tire. With each movement, a length of strand corresponding to the insertion pitch is thus inserted into the receptacle. Thanks to the guiding means 3 and the locking means 4 of the clamp 1 according to the invention, it is understood that during each insertion movement, the strand cannot bend, even if it encounters resistance in the receptacle.

[0066] There Figure 5 shows a view of a clamp according to another embodiment of the invention.

[0067] The clamp 1b differs from the clamp 1 by the locking means 3c. The locking means 3c also comprises a lower jaw 3d forming a single piece with the guide means 4, and a movable upper jaw 3e, but the latter is not connected to the lower jaw 3d by a hinge or a flexible membrane. In this embodiment, the upper jaw 3e is a detached part of the clamp, adapted to slide into the opening of the lower jaw 3d, like a piston in its sleeve. To open the clamp and accommodate the strand, it is sufficient to completely remove the upper jaw 3e from the clamp. A chain or cord, not shown, can be added between the upper jaw 3e and the clamp to prevent the loss of the small part that constitutes the upper jaw 3e. This embodiment may be suitable for a small model of clamp, where a hinge would be more fragile.In such a clamp design suitable for small section strands, the locking means may be held between the fingers, rather than in the palm of the hand, for example with the thumb positioned on the upper jaw 3e and one or more fingers positioned under the lower jaw 3d.

[0068] The components of the clamp according to the invention, as well as its total length, can actually be easily sized and adapted according to the dimensions and the cross-sectional shape of the strand to be inserted. In particular, the width of the housing 2 is a function of the width of the strand, and the shape of the housing 2 can be configured substantially circular or substantially rectangular, depending on whether the strand is of circular or rather flattened cross-section.

Claims

1. Clamp for inserting a flexurally elastic strand through an orifice of a receptacle, the clamp comprising a longitudinal housing (2) which is able to accommodate a segment of the strand and in which the strand can slide, the clamp (1, 1b) comprising: • a blocking means (3, 3c) comprising a first part (2a) of the housing, • a guide means (4) comprising a second part (2b) of the housing, the guide means (4) being configured to at least partially surround a second part of the accommodated segment and configured to guide the clamp in the direction of the orifice of the receptacle, in which clamp the blocking means (3, 3c) is able to flexurally deform a first part of the accommodated segment when an external pressure is applied to the blocking means, which is intended to be used with the strand of which the elastic force returns the first part of the segment to its initial shape when the external pressure is no longer applied, the strand being prevented from sliding by the flexural deformation of the first part of the accommodated segment, and said blocking means (3, 3c) further comprises: • a lower jaw (3a, 3d) which is fixed and secured to the guide means (4) with which it forms a single piece, comprising the first part (2a) of the housing, and • an upper jaw (3b, 3e) which is movable with respect to the rest of the clamp, able to be guided towards the lower jaw (3a, 3d) and to at least partially enter the first part (2a) of the housing in order to cover the first part of the accommodated segment, the upper jaw (3b, 3e) having a nonrectilinear profile so as to impress a nonrectilinear shape on the first part of the accommodated segment when the jaws ((3a, 3b), (3d, 3e)) are moved together, in which clamp lower contact points are disposed on the lower jaw (3a, 3d) and upper contact points are disposed on the upper jaw (3b, 3e), said contact points being configured to be disposed alternately under and over the first part of the accommodated segment in order to apply a pressure to the bottom and top of said first part of the accommodated segment, and in which clamp the jaws ((3a, 3b), (3e, 3d)) are configured to move apart from one another when said external pressure is no longer applied, the upper jaw (3b, 3e) being able to be pushed away from the lower jaw (3a, 3d) by an elastic force of the strand returning to its rectilinear shape.

2. Clamp according to Claim 1, wherein the blocking means (3) is able to be actuated by a pressure exerted by a hand clasping the two jaws (3a, 3b).

3. Clamp according to Claim 1, wherein the upper jaw (3b) can take up at least one position moved away from the lower jaw (3a), in which the housing (2, 2a) is open.

4. Clamp according to one of Claims 1 to 3, wherein the upper jaw (3b) is joined to the rest of the clamp (1) by a hinge (5).

5. Clamp according to one of Claims 1 to 3, wherein the upper jaw (3b) is joined to the rest of the clamp (1) by a flexible membrane.

6. Clamp according to one of Claims 1 to 3, wherein the upper jaw (3e) fits into the lower jaw (3d) in the manner of a piston.

7. Clamp according to one of the preceding claims, wherein the guide means (4) is a guide tube.

8. System comprising a receptacle and a clamp according to Claim 7, wherein the outside diameter of the guide tube (4) is designed for the tube to enter through the orifice of the receptacle.

9. System comprising a receptacle and a clamp according to Claim 7, wherein the receptacle is a tube for receiving the strand, and wherein the inside diameter of the guide tube (4) is designed for the receiving tube to slide in the guide tube.

10. Clamp according to Claim 7 or system according to Claim 8 or 9, wherein the opening in the second part (2b) of the housing (2) is a longitudinal slot (6) in the guide tube (4), not parallel to the guide tube.

11. Clamp or system according to Claim 10, wherein the slot follows a spiral along at least a part of the length of the guide tube (4).

12. Clamp or system according to Claim 10, wherein the slot (6) follows a sinusoidal shape along at least a part of the length of the guide tube (4).

13. Method for inserting a flexurally elastic strand through an orifice of a receptacle with the aid of a clamp (1, 1b) in accordance with Claim 1, comprising a step of positioning a strand segment in a housing (2, 2a, 2b) of the clamp, and at least one iteration of inserting a length of strand comprising the following steps of: · applying a hand pressure to the blocking means (3, 3c), having the effect of blocking the strand in the clamp by deforming a part of the strand segment, · bringing one end of the guide means (4) into contact with the orifice of the receptacle, · moving the clamp and the orifice together over a distance corresponding to the effective length of the guide means (4) and the insertion length, · releasing the pressure on the blocking means (3, 3c), having the effect of allowing the strand to slide without the housing (2a) being opened, · repositioning by moving the clamp away from the orifice over a distance corresponding to the insertion length.