Tools – Wire stripper – Bench tools
Reexamination Certificate
1999-10-14
2001-09-11
Banks, Derris H. (Department: 3723)
Tools
Wire stripper
Bench tools
C081S009410
Reexamination Certificate
active
06286393
ABSTRACT:
CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method and a device for stripping cable and wire end sections, in particular electrical or fiberoptic cables having a coaxial structure.
2. Discussion of Relevant Art
Such methods and devices have long been known. EP-B-195932 describes a type of stripping device frequently used world-wide. This structure comprises—in contrast to stripping devices for stripping continuous cables—essentially clamping jaws, centering jaws, knife jaws and a stop for the manually fed cable end section which is to be cut into and stripped—in particular in a plurality of stages. The stop performs the function of a length adjustment for the cable end section and the function of detecting that the cable end section has passed through the pre-set length and thus rests with its end against the stop, a specific distance from the clamping jaws. The stop is accordingly connected to a stop sensor.
In a further development of this structure, the stop sensor was dispensed with and instead a step was offered in which the knives or centering jaws were closed in a predetermined axial position before the insertion of the cable end section, and the cable end section could thus abut the closed knife jaws or centering jaws. Since the knife jaws or centering jaws were moved beforehand to the corresponding longitudinal position, comparably to the stop according to the EP-B, the knives and centering jaws thus fully performed the length adjusting function for the cable end section. In these two known methods and devices, no length measurement was carried out but an active pre-setting of the length with the aid of a stop or with the aid of the centering and/or knife jaws acting as a stop.
Another structure for processing continuous cables is disclosed in U.S. Pat. No. 5,522,130. A combination of light barriers and controlled drive (measuring) wheels permits positioning of the cable length relative to stationary knives.
Another method for determining the length of cable end sections or another device is described in EP-A-673099. In the case of this structure, the cable end section to be processed is introduced into the stripping device and is held there in its current axial position, which is not exactly predetermined. The actual length is then scanned by means of a scanning arrangement which is displaceable—in the longitudinal direction of this cable end section and relative to said end section—toward the free end thereof and is formed by the closed centering jaws sliding on the cable surface, and the length of the clamped cable end section is thus measured.
Whereas in the first method a length adjustment but no true length measurement is performed, in the second method a length measurement is carried out on the randomly inserted cable end section fixed in the axial position.
Both known methods have characteristics in need of improvement. The method first described is difficult to use in the case of relatively soft cable end sections. Although the method described secondly attempts to overcome this disadvantage, it is difficult to use precisely in the case of soft and thin cables. In particular, soft insulations on cable can be displaced axially relative to the conductor so that the measurement may be erroneous.
Moreover, the additional step of the length measurement in the second method delays the stripping process in comparison with the method first described.
Although a further development of the second method by the Applicant (CH-2053/96, not yet published, and WO-98/08283) improved the measuring problem in the case of soft cables having soft cable sheaths, it did not lead to accelerated stripping compared with the first method.
SUMMARY OF THE INVENTION
It is thus the object of the invention to provide a novel method and an improved device, in which thin and relatively soft cable end sections, too, can be determined with respect to length without additional loss of time.
This object of the present invention is achieved for the first time by a completely novel measurement philosophy: the length of the cable end section is neither to be actively determined by pre-setting nor to be measured after axial clamping, but, according to the invention, during the insertion into the stripping device. This novel measuring concept according to the invention has surprising advantages compared with the known one:
The time required for the length measurement is reduced virtually to zero since the measurement is performed simultaneously with the insertion of the cable. The consistency of the cable therefore does not in principle play a major role since, with appropriate design of the measuring means, a soft or curved cable, too, can be sufficiently accurately measured. The length measurement in the context of the invention relates to measuring processes with a continuously acting—in particular non-contact—measuring device which also comprises incremental or digital or stepped methods of measurement. In the simplified extreme case, the method of measurement may even comprise measurement by means of the operator's eye, for example along a built-in ruler or along a ruler printed on the cables.
In principle, the device according to the invention serves for stripping conventional cables, which however may optionally also be pre-treated. Thus, for example, it is possible to apply markings compatible with the length measurement on the surface of a cable or to print on other information which supports a measuring process—in particular an optical one.
A clamping means in the context of the invention is a device which holds the inserted cable in a specific axial position. If required, it can itself also be displaceable relative to the frame of the stripping device. Clamping means are not limited to clamping jaws alone. They might also have rotatable clamping rollers or the like. Clamping rollers in the widest sense are also not limited to individual rollers; a plurality of rollers or rollers having conveyor belts or the like might also be used. Finally, it is known that a movement of the knife device relative to the clamping means is important for stripping. The present invention comprises all possibilities for the production of such a relative movement, but expressly not continuous feeding of a continuous cable in a continuous-cable processing machine having drive rollers or drive belts, as, for example, the “Powerstrip 9500” structure of the Applicant.
The object is achieved by the features of the independent patent claims and by the independent clauses of claims
1
,
2
and
7
. Preferred embodiments and further developments and variants of the method according to the invention and of the device according to the invention are described and protected in the claims dependent thereon.
Regarding the achievement of the above-mentioned object, claim
1
goes even further in that it additionally protects stripping devices in which, not only—or instead of—the length of the inserted cable, other dimensions are measured virtually without contact. According to the invention, these may be, for example, thickness or type information which is applied to the cable either in code form and is virtually only read, or which is genuinely measured by measuring means. Industry is familiar with a very wide range of measuring devices which could be used for this purpose, for example parallel-light projectors with optical scanning, video cameras with computational image evaluation, etc.
REFERENCES:
patent: 4584912 (1986-04-01), Gudmestad et al.
patent: 4713880 (1987-12-01), Dusel et al.
patent: 4916811 (1990-04-01), Uehara et al.
patent: 5522130 (1996-06-01), Wollermann
patent: 5950505 (1999-09-01), Locher
Locher Beat
Messer Jürg
Strehl Martin
Banks Derris H.
Schleuniger Holding AG
Thomas David B.
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