The present invention is related to band tightening devices for use in banding objects, and in particular, for banding objects wherein the banding material has a reduced likelihood of buckling within such a band tightening device.
Various embodiments of band tightening tools are known, wherein such tools are used for fixedly securing bands about objects. In particular, such bands may be composed of, e.g., a plastic or metal, and the objects may be, e.g., sensors, heat shields, cables, poles and pipes. In some known band tightening tools, such as the band tightening tool disclosed in U.S. Pat. No. 5,566,726, filed Jun. 2, 1994 fully incorporated herein by reference, there is a band gripping mechanism (also denoted a “tension block”) that repeatedly grips a banding material, and pulls portions of the banding material from about an object(s) being banded, thereby tensioning the banding material about the object(s). More particularly, during tightening of a band, such a band gripping mechanism is alternately:
Such a gripper may be biased by a spring or other biasing devices to contact the banding material, at least at the commencement of the pulling of the gripping mechanism in the second direction. Moreover, such biasing must be of sufficient force to cause the gripper to securely grip the banding material. Additionally, as the gripper mechanism is pulled in the second direction, the gripping pin must apply a banding material gripping force that is sufficient to overcome any counterforce, from the band being tensioned, that the banding tool is capable of producing in the band. Accordingly, the gripper can deform the banding material in an area extending around where the gripper contacts the banding material during the band tensioning step (b) above. In particular, the banding material deformations can include depressions (and/or protrusions or raised portions) in the banding material immediately adjacent to the gripper. Moreover, when the gripping mechanism has moved its full extent in step (b) above (i.e., in the second direction) and reverses direction for moving in the first direction (i.e., step (a) above), the gripper must release its grip from the banding material. Thus, the gripping force on the banding material must be reduced at least enough so that the gripper slides over, or moves relative to, an additional length of the banding material as the gripper mechanism moves in the first direction. However, for the gripper to appropriately slide or move relative to the banding material requires that such deformed or raised portions of the banding material must not inhibit the relative movement of the gripper mechanism. In at least some circumstances, when the gripper attempts to move past such raised portions, the gripper contacts these portions with sufficient impact causing buckling of the banding material in the band tightening tool (i.e., between the gripping mechanism and the band being formed). Moreover, such buckling of the banding material within the band tightening tool can jam the tool thereby causing an operator to start the band tightening process over, and/or entirely replace the banding material being used to form the band.
The gripping assembly 24 includes an inclined opening 76 and a gripping pin 80 that is moveable therein, wherein the pin 80 is biased toward the proximal end 84 of the opening 76. Thus during operation, in step (a), the pin 80 of the gripping assembly 24 frictionally binds between the banding material 28 and an opposed portion of the proximal end 84, thereby gripping the banding material 28 so that a band tension counterforce in the direction of arrow 88 does not pull the banding material 28 from the band tightening tool 18 (which includes both the gripping mechanism 20 and the gripping assembly 24) as the gripping mechanism 20 moves in the direction of arrow 64. Once the gripping mechanism 20 has completed its movement toward the gripping assembly 24, in step (b) above, the mechanism reverses direction thereby causing the gripping mechanism to securely grip the banding material 20 and pull it in the direction of arrow 68 (as long as the force for moving the gripping mechanism 20 in the direction 68 overcomes any band tension counterforce in the direction of arrow 88). Since movement of the banding material 28 in the direction 68 causes the gripping pin 80 to release its grip on the banding material, additional banding material is pulled into the band tightening tool 18 thereby further tightening the band 36 about the object(s) 40.
However, since the gripping pin 56 can cause the banding material 28 to deform producing depressions 92 and/or raised portions 96, when the gripping mechanism 20 commences to move in the direction of arrow 64, such deformed portions of the banding material can prevent the gripping pin 56 from properly unbinding from the proximal end 72 of the opening 52. Thus, as the gripping mechanism 20 moves toward the gripping assembly 24, the banding material 20 may form a buckle 100 and jam the band tightening tool.
Accordingly, it is desirable to enhance such a band tightening tool so that the above described buckling of the banding material does not cause the tool to jam. More particularly, it is desirable to substantially prevent such banding material buckling in the tool. The invention as described hereinbelow provides such an enhancement to a band tightening tool.
The present invention is a banding material gripping mechanism and band tightening tool or apparatus for using the same, wherein there is a reduced likelihood of the banding material buckling in the tool. In particular, the present invention performs the operations of steps (a) and (b) described in the Background section hereinabove, but performs these steps with novel configurations of the gripping body and the gripper that reduce banding material buckling. In particular, the gripping body includes a central recess, and two extended portions (also denoted “wings” herein) on parallel sides of the central recess and defining the walls of the recess. More specifically, the central recess is bounded by: (i) a platform surface for supporting or guiding the banding material as the steps (a) and (b) described in the Background section above are performed, and (ii) the two walls provided by the wings of the gripping body, wherein the platform surface is therebetween. Provided within the platform surface is a novel slot whose width and length are aligned, respectively, with the width and length of the banding material traversing the platform surface when the steps (a) and (b) are iteratively performed. The slot operably cooperates with a gripper having a novel configuration, wherein the gripper includes a banding material gripping portion shaped for deforming the banding material into the slot when a banding material deforming force is applied to the gripper. The banding material gripping portion has a shape that protrudes into the banding material a furthest extent substantially at banding material locations both in line with a length of the slot, and substantially at a proximal end of the slot (i.e., the slot end where the banding material first comes in proximity to the slot). Thus, when the banding material deforms into the slot, the energy that could otherwise result in a banding material raised portion in front of (i.e., proximally) of the gripper (as described in the Background section hereinabove) is now substantially directed into deforming the banding material into the slot. Moreover, in at least some embodiments, the shape of the gripping portion may be convex relative to a width of the banding material thus causing the banding material surface being contacted by the gripping portion to become concave, and such concavity further reduces the formation of such raised portions proximal of the gripper band material deforming area.
It is also an aspect of the invention that such in slot banding material deformations are substantially adjacent to the proximal terminating end of the slot. Thus, such deformations can also serve as locks for further preventing the banding material from retracting from the band tightening tool to thereby relieve the band tightening tension.
It is also an aspect of the present invention that the gripping mechanism of the present invention may be used in prior art band tightening tools as a replacement for prior art gripping mechanisms.
Other features and benefits of the present invention will become evident from the accompanying figures, and their description including the Detailed Description hereinbelow.
Referring to
Referring to
The surface 196 extends from the ramp 194 to the distal end 192 of the platform 48m. The surface 196 includes a gripping area 208 generally identified by the shaded area of
The gripping body 30m also includes a bore 212 (
The gripping body 30m further includes at least one (and preferably two mirror image) openings 52m in the wings 184 and 188, wherein each of these openings inclines toward the platform 48m (i.e., the surface 196) as the opening extends toward the proximal end 32m of the gripping body. Note that the angular range of this inclination may be in a range of 25 to 45 degrees relative to, e.g., the surface 196, and more preferably 30 to 40 degrees, and most preferably about 35 degrees. Each of the openings 52m has a profile of an elongated circle having a circular proximal end 72m, and a distal end 214, each with a same diameter. The proximal end 72m of each opening 52m may extend to or traverse into the surface 196, and the proximal end 72m may be closer to the proximal end 32m of the gripping block than is the slot proximal end 202.
As mentioned above, the gripping mechanism 20m also includes a gripper 56m. An embodiment of the gripper 56m is shown in
When the gripper 56m is provided within the gripper block 30m, each of the cylindrical end portions 220 and 224 resides within one of the openings 52m such that the spherical portion 228 is positioned substantially midway between the wings 184 and 188. Note that the diameter of the end portions 220 and 224 is only slightly smaller than the diameter of the proximal and distal ends 72m and 218 of the openings 52m. However, the diameter difference is effective for allowing each of the cylindrical end portions 220 and 224 to substantially freely slide within its opening 52m.
The gripping body 30m further includes a pair of gripper biasing recesses 216, one in each of the wings 184 and 188. Within each wing, its biasing recess 216 is generally cylindrical in shape, closed to the central recess 180, and open on the side of the wing that is opposite the wing side facing the central recess. Moreover, the proximal end 218 of each biasing recess 216 opens into the distal end 214 of the adjacent opening 52m in the same wing. Additionally, each biasing recess 216 may be of sufficient length (between its proximal end 218 and its distal end 222) for effectively seating a biasing component such as compression spring 240 (
Thus in operation, each of the cylindrical end portions 220 and 224 of the gripper 56m is provided in one of the openings 52m so that these end portions can slidably move within their corresponding openings 52m. In particular, the gripper 56m is able to at least move (relative to the gripping block 30m) between: (1) a “released state”, wherein the truncated spherical portion 228 slides on the surface of the (any) banding material 28 (when the gripping block 30m moves the direction of arrow 64), and (2) a “gripping state”, wherein the cylindrical end portions 220 and 224 move synchronously toward the proximal ends 72m of the openings 52m and the spherical portion 228 grips the (any) banding material 28 provided on the gripping area 208. More precisely, in the released state, the gripper 56m is positioned generally at location 244 (
In one preferred embodiment, the slot 198 has depth 256 (
Various modifications of the above-described gripper mechanism 20m are also within the scope of the invention. For example, the spherical portion 228 may have a larger diameter. That is, a diameter substantially equal to the width “w” of the banding material 28, and large diameters are also within the scope of the invention. It is also contemplated that the spherical portion 228 may be replaced with a portion having a different shape than a sphere. For example, an ellipsoid (e.g., with its major axis aligned with the central axis 234) may be used. Alternatively, a cylinder may be used, wherein the cylinder is oriented (relative to the central axis 234) in the same manner as the end portions 220 and 224, and, wherein this cylinder has a thickness (along the central axis 234) of less than the width 260 of the slot 198. Furthermore, the slot 198 need not have a rectangular cross section as shown in
Regardless, of the shape of the band deforming portion 228 and the cross section of the slot 198, it is within the scope of the present invention that the gripper 56m deforms the banding material 28 in a manner that such any raised portion of the banding material 28 is substantially reduced over such raised portions that are produced by, e.g., the prior art embodiments discussed in the background section hereinabove. For instance, the present invention precludes upstream (i.e., more toward a band being created) creation of a buckle 100 (
Additionally, it is also within the scope of the present invention to provide two or more slots 198 together with a corresponding deforming portion 228 of the gripper 56m, wherein the deforming portion 228 has a shape effective for providing at least one of (1) and (2) above for a plurality banding material 28 width extents. Thus, e.g., there may be two slots 198 spaced apart so that they are near the edges of the banding material 28, and the deforming portion 228 may be shaped so as to have a profile substantially similar to a FIG. “8”.
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain the best mode(s) known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by their particular applications or uses of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.