Patent Application
20120124841
1. Filed of the Disclosure
The disclosure relates to motorized tool operative control displacement of a blade into the armor so as to prevent damage to the core of the cable.
2. Known Prior Art
Numerous tools configured to produce a cut across the armor are known. Besides effectively cutting the armor, the known tools are configured with a depth penetration control mechanism operative to prevent a blade from cutting into the core of the cable. Each of the known tools has its advantages and disadvantages the latter of which are dealt with by the disclosed tool.
The disclosed tool for producing a cut in armored cable is operative to allow the operator to set a desired depth penetration of saw blade and further control the penetration of the saw blade while cutting the armor so that it stops at the desired depth.
In accordance with one aspect, the portable tool includes a stop unit mounted on one of two clamping units which are hinged to one another. The stop unit is configured with multiple components displaceable relative to one another so that initially the desired depth is set and is further controlled.
In accordance with another aspect of the disclosure, the tool has a friction adjustment unit configured to tighten the clamping units relative to one another when the units are swung to a closed position in which they engage the cable to be cut. The friction adjustment unit is pivotally mounted on one of the clamping units and is operative to engage the other clamping unit in the closed positions of the units so that the cable is displaceably fixed during the cut.
In accordance with a further aspect of the disclosure, one of the clamping units is configured with resilient components facing the other clamping unit when the units are swung to one another to the closed position. The resilient components urge against the cable minimizing the possibility of damage to the cable when the friction adjustment unit is actuated.
The above and other features are discussed hereinbelow in conjunction with the accompanying drawings, in which:
Reference will now be made in detail to the disclosed device. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are far from precise scale. The directional terms “up, down, top, lower” and the like should be considered only relative to the plane of the drawing sheet. The terms “couple, connect” and the like do not necessarily indicate a direct engagement between components.
In operation, the user first brings a blade to a position in which it rests on armor 14 of the clamped cable, and further actuates a motor driving a saw blade unit 19 by depressing a switch 17 on a motor housing 20. As entire tool 10 rotates about cable 12, a blade of blade unit 19 penetrates the armor of cable 12 progressively at the desired depth, as explained immediately below.
To set the desired blade penetration depth, upper and lower clamping units 15 and 25, respectively, are swung away from one another. Then, the operator removably mounts one of a plurality of gages 98, which have respective differently dimensioned recesses the depth of which correspond to respective specified thicknesses of armor 14, to the bottom of platen 92. To displace the blade towards mounted gage 98, the operator actuates a nut 81 which is fixed to a screw 95 having a top sandwiched between the free end of platen 92 and a support plate 96 which are coupled together by screws 97. The manipulation of nut 81 translates to the angular displacement of entire upper clamping unit 15 relative to platen 92 and thus causes the blade to move towards the bottom of the recess provided in gage 98. Once the blade rests on the bottom of the gage's recess, the desired penetration depth corresponding to the thickness of armor 14 of cable 12 is set.
The established position of the saw blade is not fixed yet for actual cutting of armor 14 (
The stop unit 22 includes a depth indicator which, for example, may have a C- or U-shaped bracket 86, traversed by screw 95, and a pin 87 whose pin axis extends parallel to the axis of blade rotation and transversely to the longitudinal axis of screw 95. The pin 87 is mounted on and displaceably fixed to arm 91 and has a central passage threadedly engaged by screw 95. The mounting system of pin 87 includes a pair of spaced flanges 88 which are coupled to the distal end of the arm 91 by fasteners 89. The flanges 88 are mounted so that respective bores 26 are in a concentric position which allows pin 87 to be journaled in these bores.
As disclosed above, the actuation of knob 81 causes the upper clamping unit 15 to lower to the desired blade penetrating position in which the blade is rested on the bottom of the recess provided in gage 98 that may or may not be detached from platen 92 upon establishing this position. The stop position of the blade is set when pin 87 and a bottom shelf 28 of bracket 86 come into contact. Accordingly, to fix the desired penetration depth, the operator first loosens a screw 83, actuates a nut 82 threaded on screw 95 and fixed to bracket 86 which moves upwards relative to pin 87. The synchronous displacement of nut 82 and bracket 86 is realized by a stop plate 85 which is inserted into a recess on bracket 86 so as to engage nut 82. However, plate 85, which is fixed to bracket 86 by screws 84, does not preclude rotation of nut 82 relative to screw 95 which continues until bracket 86 moves along screw 95 to a position in which bottom shelf 28 of bracket 86 urges against pin 87. To ensure that nut 82 does not rotate accidentally, a biasing mechanism, including ball 99, spring 100 and set screw 101, is mounted to bracket 86 and operative to exert a dragging force upon nut 82. At this point, the position of nut 82 and bracket 86 on screw 95 is secured by set screw 83. The knob 81 is actuated again causing pin 87 and the components coupled to arm 91 to move in the opposite direction until the upper shelf of bracket 86 thereof comes into contact with pin 87. In response to the applied torque, knob 81 causes the blade to retract. The clamping units are ready now to move to the closed position thereof and engage the cable so as to commence the cutting operation. During cutting, a spring 90, penetrating an opening in low shelf 28 of C-shaped bracket 86 so as to be in contact with pin 87, biases the latter away from the flat top of screw 95 which substantially neutralizes a backlash.
To summarize the sequence of steps leading to setting the desired depth penetration of the blade, the operator rotates knob 81, for example, clockwise along with screw 95. The torque applied to screw 95 which has, for example a left-hand thread, causes pin 87 and, therefore, arm 91 and blade unit 19 to move downwards until the saw blade rests on the recess's bottom of gage 98. After that, set screw 83 is backed up, nut 82 is actuated to rotate clockwise causing C-shaped bracket 86 to move upwards relatively to pin 87 until the contact between the lower segment of pin 87 and lower shelf 28 is established. This position is registered with set screw 83 being tightened up. Afterwards knob 81 rotates in the direction opposite to the initial one displacing arm 91, pin 87 and saw unit 19 upwards, but the position of nut 82 and bracket 86 on screw 95 is fixed. Finally, cable 12 is received and tightened by friction unit 16 between clamping units 15 and 25 which are coupled to one another by the same friction adjustment unit 16, as explained below.
The operator, then, applies a torque to nut 81 so that the latter rotates in the initial clockwise direction. The saw unit 19 is displaced towards platen 92 causing the saw blade to penetrate armor 14 of cable 12. As low shelf 28 of bracket 86 comes in contact with pin 87, the displacement of the saw blade is arrested at the set depth. To remove the blade from cable 12, the operator again changes the rotational direction of knob 81 causing arm 91 and pin 87 to move upwards. Once pin 87 is in contact with the upper shelf of bracket 86, the blade is retracted from armor 14.
The support unit further has friction adjustment unit 16 configured to couple clamping units 15 and 25, respectively. The unit 16 includes a stud 105 slidably received in a recess which is provided in a free end of middle V-shaped frame 106 opposing platen 92 of
In the open position of clamping units 15, 25, respectively, friction unit 16 is swung upwards to displace stud 105 out of the recessed end of V-shaped middle frame 106. The operator then displaces clamping units 15 and 25, respectively to receive cable 12 and pivots stud 105 downwards into the recessed end of V-shaped frame 106 coupling, thus, both clamping units together. The operator further tightens nut 109 until sufficient friction is generated between cable 12 and the seat of V-shaped frames 106.
While this disclosure has described various aspects of the present invention, the latter is not limited thereto, and is susceptible to numerous changes and modifications as known to those skilled in the art. Therefore, the invention is not limited to the details shown and described herein, and includes all such changes and modifications as are encompassed by the scope of the appended claims.
