CRIMPING TOOL AND CRIMPING PROCESS

Description

Technical area

[0001] The invention relates to a crimping tool and a crimping method, in particular for automated cable assembly. State of the art

[0002] Crimping tools are used in cable assembly to permanently connect inner conductors, outer conductors, or general connector types to a free end of a cable, i.e., to crimp them. The parts to be crimped have a defined geometry that extends axially or longitudinally beyond a crimping area or crimp tabs on the respective part. A crimp sleeve or support sleeve, for example, does not fall under the category of a crimped part, as the crimp sleeve is completely crimped and does not have a geometry that extends beyond the crimping area. Crimping includes the crimping of both single- and multi-core cables.

[0003] In the prior art, a contact to be crimped is freely positioned above an anvil. Unintentional bending of the contact during crimping is prevented by a support surface and / or a contact hold-down device, so that the contact is positioned concentrically on the wire after crimping. In practice, the position of the contact above the anvil along a feed direction on the tool can be adjusted using the feed finger on the feed. The perpendicular position of the contact above the anvil along an axial direction of the contact can be adjusted by adjusting the carriage on the anvil. The support surface or contact support can comprise a plane or a geometrically rigid support surface below a mating area. The contact hold-down device can be spring-loaded or unspring-loaded and presses or holds the contact firmly onto the contact support, usually from above in a so-called crimper package.Document EP4138234A1 discloses a crimping tool according to the preamble of claim 1.

[0004] The current state of the art has at least the disadvantage that the contact can rotate and shift axially after being separated from the (contact) carrier strip. This results in crimping onto the twisted contact during crimping, resulting in an incorrectly terminated cable and thus a reject. Description of the invention

[0005] It is therefore an object of the present invention to provide a crimping tool and method in which the reject rate is at least reduced and required tolerances are maintained.

[0006] The above-mentioned object is achieved by a crimping tool according to claim 1 and a crimping method according to claim 11. Further advantageous embodiments of the invention can be found in the subclaims, the description, and the drawings.

[0007] In particular, the above-mentioned object is achieved by a crimping tool for crimping a contact onto a cable, comprising a cutter with a guide track for guiding and separating the contact from a carrier strip, an anvil for applying the contact during crimping, a crimper for crimping crimp tabs of the contact, and a first contact clamp and a second contact clamp, wherein the first contact clamp can fix the contact to the second contact clamp and the first contact clamp actuates the second contact clamp so that the second contact clamp can clamp the fixed contact. By clamping, twisting of the contact to be crimped during the crimping process can be prevented. Furthermore, the contact position, in particular also in the axial direction, can be ensured in order to comply with required tolerances.

[0008] Preferably, the first contact clamp is arranged on the crimper, and the second contact clamp is arranged on the anvil. This design allows the first contact clamp to be easily moved with the crimper toward the second contact clamp. No separate movement mechanism is required. This design aligns the second contact clamp with the anvil, allowing a contact to be crimped to be precisely aligned and positioned. Furthermore, with a reversed arrangement—i.e., if the second contact clamp were arranged on the crimper—the contact would follow a small portion of the stroke, which would be disadvantageous.

[0009] The first contact clamp preferably has a retainer that can fix the contact to the second contact clamp, wherein the retainer can switch between a resilient and a non-resilient mounting. The retainer preferably fixes the contact in a first receptacle on the second contact clamp. The retainer presses the contact (downward) onto or into the second contact clamp so that the contact is clamped flat and precisely. By switching between a non-resilient and a resilient mounting, the force exerted by the retainer on the contact can be regulated. Regulating the force protects the contact during crimping.

[0010] Preferably, the retainer is non-resiliently mounted on the first contact clamp before the contact is secured, and spring-mounted after the contact is secured. The non-resilient mounting allows maximum force transmission from the retainer to the contact. This allows the contact to be reliably secured. The spring-loaded mounting allows further movement of the first contact clamp toward the second contact clamp, in particular to actuate the second contact clamp, without a stronger force being exerted on the contact by the retainer. This stronger force could damage the contact, and this is prevented by the spring-loaded mounting.

[0011] The first contact clamp preferably has at least one actuator that actuates the second contact clamp after a contact has been secured. The actuator is, in particular, shaped or arranged on the first contact clamp such that it actuates the second contact clamp after a contact has been secured. The time offset between the securing and the actuation has the advantageous effect that the contact to be clamped is already secured and thus inhibited in its movement before it is clamped. The length of the time offset is preferably very short, in particular immediately consecutive.

[0012] Preferably, the at least one actuator comprises at least one contact surface that is oriented obliquely to the stroke direction of the first contact clamp, so that the second contact clamp is continuously moved from an open to a clamped position upon actuation. The continuous transition from the open to the clamped position has the advantage that the contact is clamped gently. A sudden or jerky transition of the position could cause unintentional damage to the contact, which is avoided with the present actuator by the continuous or smooth transition.

[0013] The first contact clamp preferably comprises at least one first stop, which, when the contact is clamped, rests against a second stop of the second contact clamp and prevents further movement of the first contact clamp in the direction of the second contact clamp. The first stop of the first contact clamp prevents further or additional clamping force on the contact when the contact rests against a second stop of the second contact clamp. This protects the contact.

[0014] Preferably, the at least one first stop and the actuator of the first contact clamp are non-resiliently mounted on the first contact clamp before the contact is clamped, and resiliently mounted after the contact is clamped. The non-resilient mounting has the effect of allowing force to be transmitted. This allows the actuator to actuate the second contact clamp and / or the first stop stops the movement of the first contact clamp when it comes into contact with the second stop on the second contact clamp, so that the contact is not damaged. The resilient mounting has the effect that the first contact clamp, when connected to the crimper, does not exert any further force on the contact or the second contact clamp as the crimper continues to move towards the anvil and the second contact clamp, thus protecting the contact.

[0015] The second contact clamp preferably has at least one first clamping jaw, which, when actuated by the first contact clamp, is moved from an open position to a clamped position. The first clamping jaw is, in particular, spring-mounted, with the spring force acting against it when moving into the clamped position. When the first contact clamp is removed from the second contact clamp, the first clamping jaw snaps open again, immediately releasing the contact.

[0016] The second contact clamp preferably has the first and at least one second clamping jaw, which can be moved toward each other when moving from the open to the clamping position and can clamp the contact between them. Clamping on both sides achieves symmetrical clamping, and the contact is held in the center. This clamping is thus more advantageous for the contact. With one-sided clamping, the contact would be bent in one direction, particularly along the clamping direction, toward the fixed clamping jaw or wall. The clamping force is identical with one or two movable clamping sides. The resulting force is the same.

[0017] The above-mentioned problems are further solved in particular by a crimping method for crimping a contact to a line, comprising the steps of: guiding the contact on a carrier tape and positioning the contact over an anvil and a second contact clamp, moving a crimper and a first contact clamp in the direction of the anvil and the second contact clamp, fixing the contact to the second contact clamp with the aid of the first contact clamp, moving the crimper and the first contact clamp further in the direction of the anvil and the second contact clamp and actuating the second contact clamp by the first contact clamp until the contact is clamped, separating the contact from the carrier tape and crimping the contact to the line.With this crimping process, a contact to be crimped is held in a desired position on the anvil, particularly by the second contact clamp, before being separated from the carrier strip. The first contact clamp initially fixes the contact to the second contact clamp and then actuates it. By holding the contact, particularly with a positive locking mechanism, unwanted rotation of the contact is prevented. Furthermore, axial displacement of the contact is prevented by a frictional locking mechanism.

[0018] Preferably, the fixing process involves pressing a retainer of the first contact clamp against the second contact clamp across the entire surface. This pressing action across the entire surface of the contact enables a gentle force transfer and securely fixes the contact to the second contact clamp.

[0019] The crimping method preferably further comprises the step: when the contact is clamped, compressing the first contact clamp until, upon removal of the crimper and the first contact clamp from the anvil and the second contact clamp, a slide is actuated by an ejection cam and the first contact clamp can rebound again. As a result of the rebound, the crimped contact on the wire can be immediately removed from the tool without the rebounding cutter bending the contact and the wire. The rebound of the first contact clamp comprises at least in particular the rebound of a hold-down device, a first stop, and an actuator on the first contact clamp. As a result of the rebound, the first contact clamp can be moved further in the direction of the second contact clamp without exerting any further or additional compressive force on the clamped contact. This protects the contact during crimping.

[0020] The following description of embodiments is made with reference to the accompanying figures. In this figure: Fig. 1 a perspective view of an embodiment of a crimping tool; Fig. 2 a perspective detailed view of Fig. 1 ; Fig. 3 a perspective detailed view of Fig. 2 with focus on an embodiment of a second contact clamp; Fig. 4 a perspective detailed view of Fig. 2 with focus on an embodiment of a first contact clamp; Fig. 5 a view along the longitudinal axis of an embodiment of a contact to be crimped at the time of positioning the contact over the embodiment of the second contact clamp; Fig. 6 the view from Fig. 5 at the time of fixing the contact to be crimped in the embodiment of the second contact clamp; Fig. 7 the view from Fig. 5at the time of actuation of the embodiment of the second contact clamp by the embodiment of the first contact clamp; and Fig. 8 the view from Fig. 5 at the time of complete clamping of the contact in the embodiment of the second contact clamping.

[0021] In the following, preferred embodiments are described in detail with reference to the accompanying figures.

[0022] Fig. 1 shows an embodiment of a crimping tool 1 for crimping a contact 2 to a line 9. In the illustrated embodiment, the contact 2 is provided on a carrier tape 4. A guide 6 together with a feed 8 move the carrier tape 4 from a storage to a processing station 7. For the movement along a feed direction X, the feed 8 engages in pilot holes 5 on the carrier tape 4 and pushes or pulls the carrier tape 4 accordingly (see Fig. 2). At the processing station 7, the contact 2 is processed, in particular crimped onto a cable 9.

[0023] The carrier tape 4 is fed at the processing station 7 to a cutter 10 with a guide track 12. The guide track 12 guides the carrier tape 4, and the cutter 10 separates a contact 2 currently to be crimped from the carrier tape 4. The cutter 10 shown also has a receptacle 14 into which a cable 9 can be inserted, to which a contact 2 is to be crimped. In addition, the receptacle 14 can comprise holders 15 so that each wire of a multi-wire cable 9 can be held at a distance from the other wire(s) in the receptacle 14 (see Fig. 3 ). The cutter 10 is movable along a stroke direction Z, in particular relative to an anvil 16.

[0024] The crimping tool 1 further comprises an anvil 16 for placing the contact 2 during crimping (see Fig. 1). The anvil 16 provides a stable and flat surface. If the cutter 10 is moved, particularly by pressure from a separating actuator 19 (see Fig. 4 ), is moved jerkily relative to the anvil 16 along the stroke direction Z, the contact 2, which is currently placed on the anvil 16, is separated from the carrier tape 4.

[0025] The crimping tool 1 further comprises a crimper 18 for crimping crimp tabs 3 of the contact 2 (see Fig. 3 and 4 ). The crimping tabs 3 can be a pair of crimping tabs 3, or as in Fig. 3 shown comprise two pairs, or generally several crimping tabs 3. The crimper 18 is preferably moved along the stroke direction Z in the direction toward or away from the anvil 16.

[0026] In the illustrated embodiment, a first contact clamp 20 is arranged on the crimper 18. In particular, the first contact clamp 20 is fixedly connected to the crimper 18 and can be moved with it (see Fig. 4). The illustrated first contact clamp 20 comprises at least one hold-down device 21, two actuators 23, each with a contact surface 25 and a first stop 27. A distance between an actuator 23 and a corresponding first stop 27 forms a cable receptacle 22. In the illustrated embodiment, two cable receptacles 22 are provided. The illustrated crimping tool 1 is particularly suitable for processing a two-wire cable. During operation, a wire of the cable 9 that is not currently to be crimped can be placed in one of the two cable receptacles 22.

[0027] The first contact clamp 20 further comprises a spring mechanism, with which the first contact clamp 20, in particular the hold-down device 21, the actuators 23, and the first stops 27, can be resiliently mounted. A change from the resilient mounting to a non-resilient mounting can be achieved by actuating a slide 24 on the first contact clamp 20, preferably by means of an ejection cam, and the first contact clamp 20 rebounds.

[0028] The illustrated first contact clamp 20 has a hold-down device 21. The hold-down device 21 is configured to fix the contact 2 to the second contact clamp 30. In particular, the hold-down device 21 is the first component to come into contact with the contact 2 during a movement of the first contact clamp 20 toward the second contact clamp 30. The hold-down device 21 can switch between a resilient and a non-resilient mounting. In the initial position, the hold-down device 21 is non-resiliently mounted.

[0029] The crimping tool 1 further comprises a second contact clamp 30 (see Fig. 3 ). The illustrated second contact clamp 30 is arranged on the anvil 16. In particular, the illustrated second contact clamp 30 is height-adjustable. The height adjustment can be carried out in different ways, in the illustrated embodiment preferably with the aid of at least three threaded pins. The anvil 16 and the second contact clamp 30 are aligned with one another in order to provide optimal support for a contact 2 to be crimped. The first contact clamp 20 can fix the contact 2 to the second contact clamp 30, in particular in a first receptacle 31. The first contact clamp 20 can further actuate the second contact clamp 30, so that the second contact clamp 30 clamps the fixed contact 2.

[0030] To clamp the contact 2, the second contact clamp 30 comprises at least one first clamping jaw 33. The first clamping jaw 33 can be moved from an open position P1 to a clamped position P2 when actuated by the first contact clamp 20. In particular, an actuator 23 of the first contact clamp 20 comprises at least one contact surface 25 that is oriented obliquely to the stroke direction Z of the first contact clamp 20, so that the second contact clamp 30 is continuously moved from an open position P1 to a clamped position P2 when actuated. If only the first clamping jaw 33 is used as the sole clamping jaw, the contact 2 is clamped between the first clamping jaw 33 and a wall. In the illustrated embodiment, the second contact clamp 30 comprises the first and a second clamping jaw 33, 34.Both clamping jaws 33, 34 are moved towards each other when moving from the open to the clamping position P1, P2 and clamp the contact 2 between them.

[0031] A practical process can be described with the following steps: First, a contact 2 to be crimped is guided on the carrier strip 4 and positioned over the anvil 16 and the second contact clamp 30. Subsequently, a cable 9 is inserted into the receptacle 14 on the cutter 10. Subsequently, the crimper 18 is moved together with the first contact clamp 20 in the direction of the anvil 16 and the second contact clamp 30. As soon as, at a first time T1, the first contact clamp 20, in particular the hold-down device 21, comes into contact with the contact 2, the fixing of the contact 2 to the second contact clamp 30 begins (see Fig. 5). The crimper 18 is then moved further together with the first contact clamp 20 along the stroke direction Z in the direction of the anvil 16 and the second contact clamp 30, whereby the contact 2 is pressed into a first receptacle 31 on the second contact clamp 30 and fixed in place. The illustrated hold-down device 21 presses the contact 2 (downward) into the second contact clamp 30 so that the contact 2 is clamped flat and in a defined manner. In particular, the illustrated fixing of the contact 2 takes place at a second time T2 by the hold-down device 21 of the first contact clamp 20 pressing the entire surface of the second contact clamp 30. In parallel, another wire of the cable 9 can be arranged in one of the two second receptacles 32. The wire in the second receptacle 32 is not taken into account in the present crimping process, i.e. in particular no forces are exerted on this wire. The second wire can already be assembled with a contact 2.

[0032] As soon as the contact 2 is fixed, the illustrated hold-down device 21 changes from a non-spring-loaded mounting to a spring-loaded one (see Fig. 6 ). The spring mechanism allows the compression of the hold-down device 21 upon further movement of the first contact clamp 20 in the direction of the second contact clamp 30. In principle, in alternative embodiments, the second contact clamp 30 can also be moved in the opposite direction in the direction of the first contact clamp 20. Upon compression of the hold-down device 21, a gap 28 forms opposite the first contact clamp 20 in the stroke direction Z (see Fig. 7 ).

[0033] By further moving the crimper 18 and the first contact clamp 20 in the direction of the anvil 16 and the second contact clamp 30, the second contact clamp 30 is actuated by the first contact clamp 20 at a third time T3 until the contact 2 is clamped. During actuation, in particular the contact surfaces 25 of the actuator 23 press against the contact surfaces 36 of the second contact clamp 30 and move the clamping jaws 33, 34 against a spring or preload force from the respective open position P1 into the respective clamping position P2. In the clamping position P2, the distance between the clamping surfaces 35 of the first and second clamping jaws 33, 34 is smaller than in the open position P1, so that the contact 2 is clamped therebetween. When clamping, in particular the clamping surfaces 35 of the clamping jaws 33, 34 exert a clamping force on the clamped contact 2.If contact 2 is clamped, it is clamped by a positive fit and rotation is no longer possible. In addition, axial displacement (along the axial direction Y) of contact 2 is prevented by friction. In the clamped state at a fourth time T4, the stops 27 of the first contact clamp 20 rest against the stops 37 of the second contact clamp 30 (see . Fig. 8 ). The first contact clamp 20 can therefore not be moved further in the direction of the second contact clamp 30.

[0034] However, in order for the contact 2 to be separated from the carrier strip 4 and crimped onto the wire 9 in a final step, the crimper 18 must be moved further toward the anvil 16. For this reason, the illustrated first contact clamp 20 is completely retracted from the moment of clamping, or from the fourth time T4. The spring mechanism also resiliently supports the actuators 23 and the first stops 27, in addition to the hold-down device 21. After the contact 2 has been separated and crimped, the crimper 18 with the first contact clamp 20 is moved along the stroke direction Z away from the anvil 16 and the second contact clamp 30. During this movement away, the contact surfaces 25 of the actuators 23 immediately detach from the first and second clamping jaws 33, 34. Since the first and second clamping jaws 33, 34 are preloaded in the direction of their initial position, ie the open position P1, the two clamping jaws 33, 34 move directly into the respective open position P1.A pin preferably limits the maximum opening of the clamping jaws 33, 34. The pin can be used to adjust the clamping travel. The contact 2 is released immediately, preventing any undesired misalignment when the wire 9 is removed from the receptacle 14. Somewhat later, during this movement away, the slide 24 on the first contact clamp 20 preferably comes into contact with an ejection cam, which causes the slide 24 to rebound the springs again, so that the first contact clamp 20 is again non-rebound. The rebound preferably occurs at approximately 40 - 60% of the return stroke (upward). After this, the crimping tool 1 returns to its starting position and is ready for the next crimping process. LIST OF REFERENCE SYMBOLS

[0035] 1 Crimping tool 2 Contact 3 Crimping tabs 4 Carrier tape 5 Pilot holes 6 Contact guide 7 Processing station 8 Feed 9 Cable 10 Cutter 12 Guideway 14 Holder 15 Brackets 16 Anvil 18 Crimper 19 Disconnect actuator 20 First contact clamp 21 Hold-down device 22 Cable holder 23 Actuator 24 Slider 25 Contact surface 27 First stop 28 Gap 30 Second contact clamp 31 First holder 32 Second holder 33 First clamping jaw 34 Second clamping jaw 35 Clamping surface 36 Contact surface 37 Second stop T1 First time T2 Second time T3 Third time T4 Fourth time X Feed direction Y Axial direction Z Stroke direction

Claims

1. Crimping tool (1) for crimping a contact (2) to a line (9), having: a) a cutter (10) having a guide track (12) for guiding and severing the contact (2) from a carrier belt (4); b) an anvil (16) for placing the contact (2) during crimping; c) a crimper (18) for crimping crimp tongues (3) of the contact (2); and d) a first contact clamp (20) and a second contact clamp (30); characterized in that d) the first contact clamp (20) can fix the contact (2) on the second contact clamp (30) and the first contact clamp (20) activates the second contact clamp (30) so that the second contact clamp (30) can firmly clamp the fixed contact (2).

2. Crimping tool (1) according to Claim 1, wherein the first contact clamp (20) is disposed on the crimper (18) and the second contact clamp (30) is disposed on the anvil (16).

3. Crimping tool (1) according to Claim 1 or 2, wherein the first contact clamp (20) has a holding-down device (21) which can fix the contact (2) on the second contact clamp (30), wherein the holding-down device (21) can alternate between a resilient and a non-resilient mounting.

4. Crimping tool (1) according to Claim 3, wherein the holding-down device (21) prior to fixing the contact (2) is non-resiliently mounted on the first contact clamp (20) and is resiliently mounted upon fixing the contact (2).

5. Crimping tool (1) according to one of Claims 1 to 4, wherein the first contact clamp (20) has at least one activator (23), which activates the second contact clamp (30) upon fixing a contact (2).

6. Crimping tool (1) according to Claim 5, wherein the at least one activator (23) comprises at least one contact face (25) which is aligned obliquely to the lifting direction (Z) of the first contact clamp (20), so that the second contact clamp (30) when activated is moved continuously from an open position (P1) to a clamping position (P2).

7. Crimping tool (1) according to one of Claims 1 to 6, wherein the first contact clamp (20) comprises at least one first stop (27) which when firmly clamping the contact (2) rests, against a second stop (37) of the second contact clamp (30) and prevents an onward movement of the first contact clamp (20) in the direction of the second contact clamp (30).

8. Crimping tool (1) according to Claim 7, wherein the at least one first stop (27) and the activator (23) of the first contact clamp (20) prior to firmly clamping the contact (2) are non-resiliently mounted on the first contact clamp (20) and are resiliently mounted upon firmly clamping the contact (2).

9. Crimping tool (1) according to one of Claims 1 to 8, wherein the second contact clamp (30) has at least one first clamping jaw (33) which when activated by the first contact clamp (20) is moved from an open position (P1) to a clamping position (P2).

10. Crimping tool (1) according to Claim 9, wherein the second contact clamp (30) has the first and at least one second clamping jaw (33, 34) which are converged when moving from the open position to the clamping position (P1, P2) and can clamp the contact (2) between them.

11. Crimping method for crimping a contact (2) to a line (9) comprising the steps: a) guiding the contact (2) on a carrier belt (4) and positioning the contact (2) over an anvil (16) and a second contact clamp (30); b) moving a crimper (18) and a first contact clamp (20) in the direction of the anvil (16) and the second contact clamp (30); c) fixing the contact (2) on the second contact clamp (30) with the aid of the first contact clamp (20); d) moving the crimper (18) and the first contact clamp (20) onward in the direction of the anvil (16) and the second contact clamp (30), and activating the second contact clamp (30) by the first contact clamp (20) until the contact (2) is firmly clamped; e) severing the contact (2) from the carrier belt (4) and crimping the contact (2) to the line (9).

12. Crimping method according to Claim 11, in which crimping method the fixing comprises pressing of a holding-down device (21) of the first contact clamp (20) against the second contact clamp (30) over the entire face of the latter.

13. Crimping method according to Claim 11 or 12, furthermore comprising the step: when the contact (2) is firmly clamped, compressing the first contact clamp (20) until a slide (24) is activated by an ejection curve, and the first contact clamp (20) can rebound again, when removing the crimper (18) and the first contact clamp (20) from the anvil (16) and the second contact clamp (30).