Two-stage shearer allowing terminal extrusion

Abstract

A system for separating a terminal (16) (e.g., an electrical terminal) from a terminal strip (17) includes a shearing tool (14) movably mounted to a frame (22) for selectively shearing the terminal (16) from the terminal strip (17). A primary shearing presser (15) is used to drive the shearing tool (14) from an initial position to an intermediate position during which the terminal (16) is sheared off from the terminal strip (17). A secondary shear presser (20) is movably mounted to the primary shear presser (15) for driving the shear tool (14) from an intermediate position after the terminal (16) has been sheared off from the terminal strip (17) to a final position.

Description

Technical Field

[0001] The present invention relates to the processing of terminals, and more particularly, to an improved system and method for separating terminals from terminal strips during crimping. Background Technology

[0002] Crimping or termination systems for attaching terminals to elements such as electrical conductors typically include an applicator configured to feed a terminal strip from a reel to a position for crimping the terminal onto the conductor. A convenient and inexpensive way to separate the terminal from the terminal strip is by using an application tool or "pressurizer" attached to a movable end of the applicator head that drives the crimping die. As the applicator head moves, the pressurizer engages with a passive terminal cutter or shearing tool that cuts the terminal from the strip just after it has been caught in the crimping tool.

[0003] Due to the requirements of crimping design, the resulting shear plane is typically positioned very close to the end of the terminal, which limits the size of the cut-off piece. However, there may be crimping designs where the volume of the conductor material of the crimped terminal and the crimping cylinder material can cause longitudinal extrusion of the crimped material. The extruded material can come into contact with or interfere with the terminal cutter positioned immediately adjacent to the sheared end of the terminal. This can be particularly likely to occur during the crimping of large terminals used with large conductors for high-voltage applications. Contact between the terminal and the terminal cutter during crimping can negatively impact the consistency and quality of the resulting crimp. Summary of the Invention

[0004] Therefore, there is a need for improved systems and methods to prevent extruded terminal material from engaging or contacting the terminal cutter during the crimping process.

[0005] In one embodiment of this disclosure, the system for separating a terminal from a terminal strip includes a cutting tool movably mounted to a fixed frame. A primary cutting presser drives the cutting tool from an initial position to an intermediate position and selectively cuts the terminal from the terminal strip. A secondary cutting presser is movably mounted to the primary cutting presser for further driving the cutting tool from the intermediate position, after the terminal has been cut from the terminal strip, to a final position. Attached Figure Description

[0006] The invention will now be described by way of example with reference to the accompanying drawings, in which:

[0007] Figure 1 This is a side perspective view of a terminal applicator according to an embodiment of the present disclosure;

[0008] Figure 2 yes Figure 1 Second side perspective view of the terminal applicator;

[0009] Figure 3 yes Figure 1 A perspective view of the terminal applicator;

[0010] Figure 4 This is a perspective view of the terminal applicator in the first stage of the shearing process;

[0011] Figure 5 This is a perspective view of the terminal applicator after the first stage of the shearing process is completed;

[0012] Figure 6 This is a perspective view of the terminal applicator after the second stage of the shearing process or the second stage of the shearing motion is completed; and

[0013] Figure 7 This is a partial cross-sectional view of a primary shear presser and a secondary shear presser according to embodiments of the present disclosure. Detailed Implementation

[0014] According to embodiments of this disclosure, a system is provided for separating terminals (e.g., electrical terminals) from a terminal strip comprising a plurality of terminals during a crimping operation. The system includes a movable terminal cutter or cutting tool for receiving the terminals from the terminal strip. The cutting tool is driven from an initial position (e.g., downward) to an intermediate position by a primary shear presser for cutting the terminals from the strip. The primary presser may be fixedly mounted to an applicator head or crimping actuator that performs the crimping operation on the terminals after they have been separated. A secondary shear presser according to embodiments of this disclosure is movably mounted to the primary shear presser. After the terminals have been cut from the terminal strip and the primary presser has reached the end of its stroke, the secondary shear presser operates to drive the terminal cutter further downward from the intermediate position and out of an extrusion space into which the crimped terminals may have extended during crimping. The operation of the secondary shear presser can be inherently passive, operating automatically without requiring additional operator and / or control system input.

[0015] Embodiments of this disclosure will be described in more detail in the context of exemplary simplified systems or terminal applicators for crimping electrical terminals onto conductors. Specifically, refer to Figures 1 to 3A terminal applicator 10 for performing termination or crimping operations is configured to feed a terminal strip 17 comprising a plurality of interconnected terminals 16 to a crimping position where the free end of a wire or cable is secured thereto. The applicator 10 includes a movable crimping die 12 and an opposing stationary crimping die 13, with the terminals 16 arranged between the movable and stationary crimping dies in the crimping position. The crimping die 12 is fixedly connected to a movable end of an applicator head or crimping actuator 18. As shown, the applicator head 18 may include, for example, one or more pneumatic or hydraulic cylinders or motor-driven mechanisms for selectively moving the crimping die 12 vertically during the crimping operation.

[0016] As described above, a passive terminal cutter or cutting tool 14 is provided for cutting or separating the terminal 16 from the remainder of the terminal strip or band 17 prior to but in conjunction with the crimping process. Specifically, the exemplary terminal cutter 14 includes a body having a slotted opening 19 formed therethrough and defining a cutting blade or edge. The opening 19 receives the terminal strip 17 therein in a direction orthogonal to the direction of movement of the terminal cutter 14 (e.g., vertical direction), such as... Figure 1 As shown. When terminal 16 is inserted into terminal cutter 14, the downward extension of applicator head 18 is operable to bias the terminal cutter downward via contact with main pressure unit 15 for cutting individual terminals 16 from terminal strip 17.

[0017] The terminal cutter 14 can be movably or floatingly mounted to the applicator 10, and more specifically, to its frame 22. In one embodiment, the terminal cutter 14 is resiliently mounted relative to the fixed frame 22 so as to resiliently return from the final post-cut position after the cutting and crimping operations have been performed. Figure 1 The initial position is shown. More specifically, the shearer 14 can be biased in a vertically upward direction by one or more elastic elements (e.g., one or more springs 21), as shown. Figure 3 As shown. However, it should be understood that, without departing from the scope of this disclosure, the terminal cutter 14 can be floatably mounted and / or elastically biased by other arrangements, including spring elements positioned in any suitable location.

[0018] Embodiments of this disclosure include a two-stage presser for engaging with a terminal cutter 14 to perform an improved shearing operation. Specifically, the terminal shear presser includes a primary shear presser or a first-stage shear presser 15. By way of example only, the first-stage shear presser 15 may be in the form of a rigid cylinder. In an exemplary embodiment, the primary shear presser 15 is fixedly attached to a movable end of the applicator head 18. As described above, the first-stage shear presser 15 is operable to engage with the terminal cutter 14 and apply a downward force to the terminal cutter 14 to perform a shearing operation as the crimping die 12 moves downward toward the terminal 16.

[0019] As described above, and as those skilled in the art will understand, during the crimping process, terminal 16 can be elongated or extruded via plastic deformation. This may cause terminal 16 to come into contact with terminal cutter 14, which is arranged adjacent to terminal 16 after a cutting operation. Embodiments of this disclosure provide a means to ensure that terminal cutter 14 does not interfere with or contact terminal 16 due to extrusion of terminal 16 during crimping.

[0020] Specifically, a second-stage pressure cutter or passive shear cutter 20 according to this disclosure is provided, which includes a movable plunger or piston disposed on and / or within an end of the first-stage shear cutter 15. In an exemplary embodiment, the second-stage shear cutter 20 may be in the form of a cylindrical element. Of course, other shapes of the first-stage pressure cutter 15 and the second-stage pressure cutter 20 are contemplated without departing from the scope of this disclosure.

[0021] The second-stage pressure reducer 20 can be used as follows: Figures 1 to 3 and Figure 6 The extended position shown is similar to... Figure 4 and Figure 5 The device moves between the indicated contraction positions. As described herein, the second-stage presser 20 operably engages with the terminal cutter 14 and biases the terminal cutter 14 from an intermediate, post-cut position after the terminal 16 has been cut from the terminal strip 17 to a final position outside the extrusion area of ​​the terminal. In an exemplary embodiment, the base 22 defines a recess or opening 24 for receiving the terminal cutter 14 when it is further biased downward during this second-stage movement.

[0022] The second-stage presser 20 can be passively and elastically biased to the extended position via an internal spring arranged within the first-stage shear presser 15. For example... Figure 7As shown, the second-stage shear reducer 20 can be coaxially aligned with the first-stage shear reducer 15 and is slidably arranged together with an elastic element 32 (e.g., a helical spring) within a corresponding cylindrical opening 30 formed in the free end of the first-stage shear reducer. While the spring-loaded second-stage shear reducer 20 is shown and described, other means can be used to passively bias the second-stage shear reducer to an extended position, such as with a fluid (e.g., air or hydraulic fluid). In other embodiments, as those skilled in the art will understand, the second-stage reducer 20 can be actively controlled via, for example, one or more actuators combined with a solenoid and associated control / processing hardware and software.

[0023] The operation of the two-stage shear press is as follows Figure 4-6 As shown. Reference Figure 4 The moving end of the applicator head 18 has lowered the first-stage shear presser 15 into contact with the terminal cutter 14. The terminal cutter 14 is then biased into initial contact with the terminal 16 of the terminal strip 17. Simultaneously, the second-stage presser 20 is biased into a retracted position within an opening formed in the end of the first-stage shear presser 15. More specifically, the elastic force biasing the second-stage presser 20 into the extended position is selected to be less than the force required to cut the terminal 16 from the terminal strip 17. In this way, the second-stage presser 20 is adapted to be passively biased into the retracted position before the terminal cutter 14 cuts the terminal 16.

[0024] like Figure 5 and Figure 6 As shown, the shearing step is accomplished by a continuous downward force acting on the terminal shearer 14 via the first-stage shear presser 15. After the terminal 16 is sheared, the closing of the crimping dies 12, 13 may cause the terminal 16 to be extruded. More specifically, according to embodiments of the prior art, the terminal shearer 14 may remain in the extrusion path of the terminal 16 until the crimping operation is completed, after which the terminal shearer 14 is allowed to return to its initial position.

[0025] However, according to embodiments of this disclosure, at the point when the terminal cutter 14 has just passed through the strip 17 and disconnected the terminal 16 from it, the force resisting the extension of the second-stage presser 20 is released. As an example, the second-stage presser 20 is now able to extend freely from the end of the first-stage shear presser 15 under the biasing force of the spring. As it extends, the second-stage presser 20 is operable to further push or bias the terminal cutter 14 vertically downward from its intermediate position, and push or bias it away from the extrusion area of ​​the terminal 16. Figure 6As shown, in the lower or final position, the terminal cutter 14 is positioned completely below the terminal 16 and / or terminal strip 17 to prevent it from interfering with the extrusion or elongation of the terminal 16 during subsequent crimping. It should be understood that the spring force or biasing force acting on the second-stage presser 20 is selected to be greater than the return force that biases the terminal cutter 14 to its initial position, but less than the force required to cut the terminal 16.

[0026] Therefore, embodiments of this disclosure add a low-force tool or actuator as a second tool within the primary shear presser, which rapidly actuates the terminal cutter and removes it from the extrusion area or window of the terminal to be crimped. After the terminal cutter has completed cutting the terminal from the strip, there is almost no resistance to further downward movement. Therefore, the low-force stroke, as a second stroke, then accelerates the terminal cutter downward and removes it from the extrusion window before significant extrusion may occur. The second-stage presser may always be active (e.g., by spring or air pressure), but with sufficiently low extension force so that the final shear position is unaffected until shearing is complete. In this way, no actively controlled motor or valve is required, nor is software controlling its operation necessary.

Claims

1. A system for separating terminals (16) from a terminal strip (17) comprising a plurality of interconnected terminals (16), comprising: A movable cutting tool (14); Primary shear presser (15) drives the shearing tool (14) from an initial position to an intermediate position; and Secondary shear presser (20), which is movably mounted to the primary shear presser (15), drives the shearing tool (14) from the intermediate position after the terminal has been cut from the terminal strip to the final position.

2. The system according to claim 1, wherein, The secondary shear presser (15) drives the shearing tool (14) away from the extrusion path of the terminal (16) during the crimping operation.

3. The system according to claim 1, wherein, The secondary shear presser (20) is elastically mounted to the end of the primary shear presser (15), and the elastic force biases the secondary shear presser (20) to an extended position relative to the primary shear presser (15).

4. The system according to claim 3, wherein, The elastic force of the biased secondary shear presser (20) is less than the force required to cut the terminal (16) from the terminal strip (17) with the shearing tool (14).

5. The system according to claim 4, wherein, The shearing tool (14) is elastically biased in a direction opposite to the shearing direction of the shearing tool.

6. The system according to claim 5, wherein, The elastic force that biases the secondary shear presser (20) to the extended position is greater than the elastic biasing force acting on the shearing tool (14) in the direction opposite to the shearing direction.

7. The system according to claim 6, further comprising: A fixed frame (22) supports the cutting tool (14). A crimping actuator (18) having a movable end and a fixed end mounted to the frame (22), wherein the primary shearing presser (15) and the secondary shearing presser (20) are mounted to the movable end of the crimping actuator (18); and A crimping die (12), which is fixed to the movable end of the crimping actuator (18), is used to crimp the terminal (16) after it has been cut from the terminal strip (17).

8. The system according to claim 3, wherein, The secondary shear presser (20) is biased by the shearing tool (14) to a retracted position relative to the primary shear presser (15).

9. The system according to claim 8, wherein, When the primary shear presser (15) contacts the shearing tool (14), the secondary shear presser (20) is biased to the contracted position.

10. The system according to claim 9, wherein, The secondary shear depressor (20) is a spring-biased piston that is received within the primary shear depressor (15) in the contracted position.

11. The system according to claim 1 further includes a spring (32) arranged between the primary shear presser (15) and the secondary shear presser (20).

12. A shearing tool presser (15, 20) for a terminal applicator (10), comprising: A first body (15) is fixedly mounted to a crimping actuator (18) of the terminal applicator (10), and the free end of the first body (15) is adapted to drive a shearing tool (14) of the terminal applicator (10) to separate a single terminal (16) from a terminal strip (17) comprising a plurality of terminals (16). and The second body (20) is movably and elastically mounted to the free end of the first body (15) and is adapted to engage with the cutting tool (14).

13. The shearing tool presser (15, 20) according to claim 12, wherein, The second body (20) is movable along the axial direction of the first body (15), and the second body (20) is elastically biased in a direction away from the first body (15).

14. The shearing tool presser (15, 20) according to claim 13, wherein, The bias force acting on the second body (20) is less than the force required to cut the terminal (16) from the terminal strip (17).

15. The shearing tool presser (15, 20) according to claim 14 further includes a spring (32) disposed between the first body (15) and the second body (20), the second body (20) and the spring (32) being received in an opening (30) formed in the free end of the first body (15).

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