Lock between band and buckle of band clamp

Abstract: A band clamp has an improved lock between a band (304) and a buckle (302) of the band clamp. The improved lock is of the type of lock where the band (304) is passed through the buckle (302) and then shaped to form a locking surface (332) that engages the exterior of the buckle (302) to prevent the band (304) from being pulled back through the buckle. Characteristic of the improved lock is that the lateral cross-section of the locking surface (332) is, in one embodiment substantially V-shaped. In other embodiments, the lateral cross-section is substantially U-shaped and substantially Ω-shaped.

Description: The invention of this application relates generally to securing a band to a buckle of a band clamp and is related to the invention of our co-pending application EP-A-479602 (91309104.7), the disclosure of which corresponds to the description of this application related to Figures 1 to 8 hereof and on which co-pending application the pre-characterising portions of claims 1 and 7 of this application are based. It is particularly concerned with a lock between a band and a buckle as well as an apparatus and method for forming the lock. The use of a hand tool to tighten a band clamp has long been known. Band clamps are typically used to secure bundles of materials together and to secure pipes, wiring, etc. In one such application, a band clamp is applied to secure a protective metal braiding around a bundle of wiring which is connected to a plug or coupler known as a back shell. Back shells are frequently used in military and aerospace applications where wiring carrying low voltage signals are conducted. Both the cables and the connectors must be protectively covered with a metallic substance to limit the harmful effects of radiation thereon. This metallic shielding must be without any "windows" (openings) and must in all parts have a ground connection with only low resistance to effectively minimize any electrical potential this "shielding" system may receive due to external or internal electromagnetic radiation (such as radio emission, cosmic rays, lightning strike, explosion of an atomic device, etc.). The diameter of the back shell body is typically larger than the diameter of the cable entering thereinto, and in order to have a satisfactory interconnection, a banding tool must be capable of applying a band clamp proximate the intersection of the back shell body and the cable entry stem. Thus the banding tool should be approximately the same width as the band clamp to be applied and should be capable of applying the band clamp from any direction. One tool for tightening band clamps to a back shell is disclosed in U.S. Patent No. 4,726,403, to Young et al., February 23, 1988. The Young et al. device uses a toggle arrangement to tension the band clamp in place. Upon reaching the appropriate tension in the band clamp, the tool locks in a closed condition. To sever the tail from the tightened band clamp, a cutting arm must be rotated outwardly and upwardly from the side of the banding tool. Due to the externally attached cutting device, the Young et al. banding tool is capable of applying a band clamp close to the back shell from only one direction. If a band is attempted to be connected from the opposite direction, the cutting device may prevent proper installation. The Young et al. tool is therefore limited in its application and becomes difficult to operate in confined spaces such as are found in aircraft fuselages. Additionally, Young's tool uses toggles to transfer tension and toggles generally have a short power stroke in order to make the tool usable by an average person. Therefore, a larger size tool is required to sufficiently tension the band. Another banding tool is disclosed in U.S. Patent No. 4,928,738 to Marelin et al., May 29, 1990, assigned to the same assignee as the present invention. The '738 tool uses toggles to provide the power stroke and counteracting springs to achieve the desired tension in a band. It is necessary to force the band to bend around internal portions of the tool during tensioning. Additionally, the tool is not designed with overall width as a primary consideration. Still another banding tool is disclosed in U.S. Patent No. 2,087,655 to Prestwich, July 20, 1937, the '655 device has a gripper section which holds one end of the band to be tensioned while a tensioning section grips and pull the other end of the band. The tensioning section comprises a double set of knurled wheels with a first set fixed and a second set movable. While the first set prevents slippage of the band, the second set tensions the band. While there is an angle between the tensioning section and the gripper section, this angular relationship does not provide the advantages of the present invention. Thus there is a need for a method and apparatus to allow tensioning of a band clamp to a back shell from either direction. An additional concern is the lock established between the band and the buckle of a band clamp. Particularly, the type of lock that is of concern is one in which the free end of a band, whose other end is operatively attached to a buckle, is wrapped about an object and inserted through a passageway extending through the buckle and then bent to create a surface which engages the exterior of the buckle preventing the band from pulling back through. The lock itself is defined by the engagement of the band to the exterior of the buckle. For example, in one lock of this type known to those skilled in the art, the lock is formed by bending the band transverse to the length of the band and away from the object about which the band clamp is wrapped to create the surface, a lip, which engages the upper exterior surface of the buckle to lock the band in place. The known locks of the type that are formed by bending the band to create a surface that engages the exterior surface of the buckle suffer from many deficiencies and inadequacies. Particularly, a problem prevalent among known locks of this type is their lack of holding power in certain circumstances. One such circumstance is when the lock is used to secure a band clamp about an object which is capable of expansion and contraction. In this situation, the known locks of the aforementioned type are susceptible to failure upon expansion of the object. Consequently, there is a need for a lock of the aforementioned type that exhibits improved strength in these and like circumstances. A further problem of known locks of the stated type is the force required of the banding tool to create the lock. In many instances, the force necessary to create the locks necessitates the use of a power tool or if a hand tool is employed, considerable force must typically be applied by the operator. For example, in the lock in which the band is bent transverse to its longitudinal axis and away from the object about which the band clamp is wrapped, the devices presently used to shear off the excess band make the entire cut at one time. Further, the force necessary to make the entire cut at once increases as the width of the band increases and as the thickness of the band increases. However, the use of a power tool is not practical in many applications. Similarly, in many situations it is not possible for an operator to apply the requisite force to a hand tool. Consequently, there is a further need for a lock that can be readily formed with hand banding tools. An additional problem in the aforementioned type of lock is its susceptibility to snagging. Specifically, the known locks of this type are formed in a manner in which they are susceptible to failure due to edges of the lock snagging on articles that can destroy the lock between the band and the buckle by "unbending" the band. For example, the lock formed by bending the band transverse to its longitudinal axis typically has an exposed edge where the excess band has been sheared that is readily snagged. Further, the snagged edge of the lock may damage the material or object that has been snagged. As is apparent, there is a further need for a lock of the defined type that is less susceptible to snagging. A further problem in the known locks of the aforementioned type is their susceptibility to tampering. For example, the known lock in which the edge of the band is bent away from the object about which the band is wrapped can be defeated with simple tools, such as a pair of pliers, and by hand in some instances. Therefore, there is an additional need for a lock of the defined type that is less susceptible to tampering. A further problem for locks of the aforementioned type, and especially those in which the band is bent transverse to the length of the band to create a lip that engages the upper exterior surface of the buckle, is that the tool which is used to create the lock and the clamped object must be rotated relative to one another to form the lip. During this rotation process, it is necessary to release some of the tension in the band to prevent the portion where the lock is to be established from thinning or breaking. Hence there is a need for a lock that can be formed while substantially avoiding having to release tension in the band, relative rotation between the band and the clamped object, or thinning of the band in the lock area due to rotation. A further problem of the known locks of the aforementioned type is the inability of one banding tool to create the locks with various widths of the band. Consequently, a separate banding tool must be acquired for each width of band and associated buckle that is employed. Hence, there is a need for a lock that can be formed in band clamps of varying widths by one banding tool. An additional problem of the known locks is their relative short life. Band clamps are often used in circumstances where they are unprotected from various elements, including the weather, and under great force. In these circumstances, the formation of known locks do not provide the long-life characteristics desired. A further problem of the known locks is the difficulty in forming a proper lock in circumstances wherein the bundle or object sought to be secured is, for example, at a remote location. The known locks are inadequately designed to be formed by hand-held tools as opposed to machine tools, due to the forces required to form the lock. According to one aspect of the invention there is provided a band clamp, comprising: a buckle having a longitudinally extending passageway for receiving a band, said passageway having an entrance and an exit, said exit being defined by an edge of said buckle; said band having a first lateral edge, a second lateral edge, a first end operatively attached to said buckle and a second end for wrapping about an object and for inserting into said passageway; wherein at least a portion of said second end of said band extends through said passageway and beyond said exit and said second end of said band is cut for forming a lock between said band and said buckle, said band clamp being characterized in that: said cut begins at a first point that is located between said first lateral edge and said second lateral edge and terminates at a second point that is different from said first point and is located in between said first lateral edge and said second lateral edge. According to another aspect of the invention there is provided a method for establishing a lock between a band and a buckle, comprising: providing a buckle having a longitudinally extending passageway for receiving a band, said passageway having an entrance and an exit, said exit being defined by an edge of said buckle; providing a band having a first lateral edge, a second lateral edge, a first end operatively attached to said buckle, and a second end for wrapping about an object and inserting into said passageway; wrapping said second end of said band about said object; inserting said second end of said band through said passageway so that at least a portion of said second end extends beyond said exit; and cutting said second end of said band so that a lock can be formed between said band and said buckle, characterised in that: said cutting begins at a first point that is located in between said first lateral edge and said second lateral edge and terminates at a second point that is different to said first point and is located in between said first lateral edge and said second lateral edge. In accordance with one embodiment of the invention, a portion of the band located intermediate to the lateral edges of the band is bent substantially parallel to the passageway of the buckle to create the surface that engages the exterior of the buckle to form a lock. Stated another way, the band is bent in a manner that produces a substantially Ω-shaped transverse cross-section. Formed in this way, the exposed edges are reduced thereby reducing the chances that the integrity of the lock will be compromised. A lock cover provided on the upper portion of the buckle can protect the aforementioned Ω-shaped lock against tampering. Further, the lock cover and lock permit a banding tool to be designed that can be used to form the lock with bands and buckles of various widths. Based on the foregoing, the present invention can provide a lock which is able to withstand greater forces, and in various embodiments is long lasting, less susceptible to snagging or tampering, able to be easily formed, and can be formed while substantially avoiding the release of tension in the band, relative rotation between the band and the clamped object, or thinning of the band in the regions of the lock due to this rotation. The present invention, in at least one embodiment, provides a lock so that a banding tool can be designed to accommodate band clamps of various widths. Furthermore, the present invention provides a tool and a method for forming such a lock. The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which:- Figure 1 is a perspective view of a tool constructed in accordance with our co-pending application EP-A-479602 in use; Figures 2a, b, and c are exploded perspective views of the tool of Figure 1; Figures 3a and b are cross-sectional views of the tool with a band clamp to be tensioned being inserted therein; Figures 4a, b and c are cross-sectional views of the tool in an upstroke position; Figures 5a and b are cross-sectional views of the tool in the signal position; Figures 6a, b and c are side cross-sectional views of the cutting operation; Figures 7a and b are isometric views of one embodiment of a locking tab and the hardware required for formation thereof; and Figures 8a and b are isometric views of another embodiment of a locking tab and the hardware required for formation thereof. Figures 9a-9d are, respectively, top, cross-sectional end, side, and perspective views of one embodiment of a lock of a tool according to the invention; Figures 10a-10d are, respectively, top, cross-sectional end, side, and perspective views of another embodiment of a lock of a tool according to the invention; Figures 11a-11d are, respectively, side, bottom, front, and perspective views of a cut-off knife and cut-off blade used to form the lock illustrated in Figs. 9a-9d and 10a-10d. Referring first to Figure 1, a tool is generally identified by the reference numeral 10. The banding tool 10 is used to attach a band clamp 12 comprising a band 13 and a buckle 15 to a coupler 14 such as, for example, a back shell. The band clamp 12 is used to secure a protective shield 17 covering a cable 16 which is in turn attached to the coupler 14. Optional protective cover 16a such as heat shrink tubing can be installed to cover the shield 17 and the buckle 15. Due to a larger diameter D of the coupler 14 in comparison to a diameter d of the shield 17, a flange 18 is formed proximate the connection therebetween. As a result of the banding tool 10, the band clamp 12 may be positioned proximate the flange 18 as required for the preferred connection configuration. Also, due to the symmetrical design of the tool 10, the band clamp 12 may be positioned proximate the flange 18 from either direction (i.e. the tool 10 may also be used to apply the clamp 12 from a direction indicated by an arrow 19, directly opposite the direction as shown in Fig. 1) with equal success. It should be noted that the tool 10 may be provided with handle locks 21 that allow the tool 10 to be stored in a more compact and space efficient manner. Referring simultaneously to Figures 2a, 2b and 2c, an exploded perspective view of the tool 10 is shown. A housing 20 receives and interconnects the various parts of the tool 10. Within a hollow handle 22 (the handle 22 may be provided with a protective covering 23 of a pliant material for comfort during use) of the housing 20 is a tensioning assembly 24. The tensioning assembly 24 comprises a force storing device 26, a tension adjustment plunger 28, a tension adjustment screw 30 and a connecting rod 32. The device 26 may comprise, for example, a compression spring, a rubber block or any other device capable of storing energy. Alternatively, the device 26 may comprise a power unit such as a hydraulic or pneumatic cylinder for powered actuation of the tool 10. The screw 30 is threadably received into a tubular portion 33 of the rod 32. The plunger 28, upon assembly, is secured to the adjustment screw 30 to precompress the device 26 by threading into or out of the tubular portion 33 of the rod 32. A special tool (not shown) is preferably required to turn the plunger 28 and thus the screw 30 to prevent unauthorized changing of the setting of the desired recompression of the device 26. As will be subsequently described in greater detail, the device 26 is precompressed to allow a desired tension to be applied to the band clamp 12 around an object to be clamped. The housing 20 also comprises a head receptacle 34 in which a head 36 (See Fig. 2b) is operably interconnected to the tensioning assembly 24. It is an important aspect of the present invention to note that upon assembly, a linear axis 38 passing through the tensioning assembly 24 intersects a linear axis 40 through the head 36 at an angle A (see Fig. 3a). The angle A may vary so long as the axis 38 and the axis 40 are not parallel to each other. The angular relationship between the assembly 24 and the head 36 allows the band 13 to be inserted into and through the tool 10 without the necessity of bending around an obstruction in the tool 10. Therefore, in comparison to prior devices the tool 10 is easy to load and most of the force in the tool 10 is used to tension the band 13 rather than to bend the band 13 around an obstruction. The head 36 is interconnected to the assembly 24 by push links 42, tension transfer lever 44 and tension block 46. The tension block 46 is slidably inserted into a cavity 48 in the head 36 and connected to a first end 50 of the lever 44 by a pin 52. The lever 44 is also pivotally connected through a center hole 60 to the head 36 by a pin 62. A second end 54 of the lever 44 is pivotally connected to a first end 56 of the links 42 by a pin 58. The links 42 are connected at a second end 64 to the connecting rod 32 by a pin 66. A support plunger 68 is secured to the rod 32 forcing pin 66 against forward end of elongated slot 72 on the rod 32 through which the pin 66 is positioned. Due to the slot 72, the pin 66 has a predetermined travel distance along the linear axis 38, as will be subsequently described in greater detail. The cavity 48 in the head 36 is dimensioned to allow the tension block 46 to slide in a back-and-forth direction as indicated by a double-headed arrow 74. Received within an elongated slot 76 (see Fig. 2c) in the tension block 46 is a tension pin 78. The slot 76 is formed at an angle B (which may comprise, for example 10°-17°) relative to a top surface 80 of the block 46 to allow pressure to be applied and released by the tension pin 78 to the band 13 of the band clamp 12, as will be subsequently described in greater detail. A pair of springs 82 are inserted into holes 84 in the block 46 to bias the pin 78 toward an edge 210 (see Fig. 2c) of the slot 76 and into contact with the band 13 of the band clamp 12 which passes therebetween and a bottom surface 85 of the block 46. A tension holding pin 92 is slidably received within an elongated slot 94 in the head 36. The pin 92 is held within the slot 94 by engagement of a groove 93 therein by a tension hold/release link 106. Thus the width of the tool 10 at the head 36 is kept to approximately the same width as the buckle 15. The slot 94 is formed at an angle C (which may comprise, for example, 10°-17°) relative to a top surface 96 of the head 36 (see Fig. 2b). The pin 92 is biased away from an edge 212 of the slot 94 by a spring 98 which fits through the head 36 in opening 100. The spring 98 is held in place by a recess 102 in a tension holding hook 104. The band 13 of the band clamp 12 is gripped between the tension holding pin 92 and a cut-off blade 86. Thus the tension holding pin 92 is biased.to hold the band 13 from slipping or being pulled from the tool 10. The cut-off blade 86 may be reversibly fixed within the head 36 by a pin 88. A jam screw 90 is threadable into the blade 86 to hold pin 88 in place and to provide convenient means to remove cut-off blade 86. The tension hold/release link 106 fits within the head 36 through an opening 108 for cooperation with a tension hold/release hook 110. The link 106 and hook 110 are interconnected by the mating of a male portion 112 on the hook 110 with a slot 114 on the link 106. The hook 110 is pivotally connected to a pull-up handle 116 by a pin 118. The hook 110 may be provided with a pliant cover 120 for comfort of use. The link 106 has a first cut-out 122 and a second cut-out 124. When the link 106 is installed within the head 36, the first cut-out 122 interacts with the tension pin 78 of the tension block 46 while the second cut-out 124 interacts with the tension holding pin 92 within the elongated slot 94 of the head 36. By actuating the hook 110 in a direction indicted by an arrow 126 the hook 110 pivots about the pin 118 to pull the link 106 in a direction indicated by an arrow 128. The first cut-out 122 and the second cut-out 124 thus contact the tension pin 78 and the tension holding pin 92, respectively, and pull the pins against their spring bias. Thus, an operator is able to insert a band 13 of the band clamp 12 without interference from the tool 10. The link 106 also provides an automatic self adjustment when clamping various materials such as steel versus rubber. For example, if the band clamp 12 encircles a rubber tube, there will be a greater tendency (than with steel) for the rubber to try to re-expand and to pull the tension holding pin 92 into the elongated slot 94 away from the edge 212 (thus gripping the band 13 tighter). This forward motion of pin 92 would reduce the total stroke tool 10 could apply to band 13, resulting in lower tensioning force. Due to the interconnection with the tension pin 78 through the link 106, the tension pin 78 will be similarly allowed to move farther into its elongated slot 76 toward the edge 210 for greater gripping strength, thus adjusting automatically for a longer stroke. The pull up handle 116 is pivotally connected to the connection rod 32 by a pin 130 passing through holes 132 and 133. The pull up handle 116 is pivotally connected to the head receptacle 34 by a pin 134 through a hole 136 in the head 34 and a hole 138 in the handle 116 and is held in position by snap rings 135. The handle 116 may be provided with a pliant cover 140 for comfort of operation. A spring 142 is inserted into a receptacle 144 in the handle 116 and into the head receptacle 34 to bias the handle 116 in a direction indicated by an arrow 146. A plurality of bolts 148 fit into holes 150 in the head receptacle 34 and are threadably received by the head 36 within holes 152 therein. Thus, the head 36 is secured within the head receptacle 34 by the bolts 148. A cutoff handle 154 is pivotally attached to the head receptacle 34 by a pin 156, secured in place by a pair of snap rings 162, passing through holes 158 in the receptacle 34 and a hole 160 in the handle 154. A spring 164 is positioned between the handle 154 and the head receptacle 34 to bias the handle 154 in a direction indicated by an arrow 166. The handle 154 may also be provided with a pliant cover 168 for comfort of operation. A pair of cutoff links 170 are pivotally attached to the handle 154 by a pin 172. The cutoff links 170 are pivotally attached at an end opposite the handle 154 to a cutoff arm 174 by a pin 176 which is held in place by snap rings 177. A pin 178 passes through the links 170 for interaction with the tension holding hook 104, as will be subsequently described in greater detail. The cutoff arm 174 is pivotally connected to a cutoff knife 180 by a pin 182 and to the head 36 by a pin 184. The cutoff knife 180 is slidably received within a receptacle 186 in the head 36 for cooperation with the cutoff blade 86 to sever the band 13, as will be subsequently described in greater detail. The tension holding hook 104 has a hook 188 and a cam surface 190. The tension holding hook 104 is pivotally connected to the head 36 by a pin 192. A spring 194 is received by the tension holding hook 104 and a receptacle 196 in the tension transfer lever 44. The spring 194 biases the tension holding link 104 in a counterclockwise direction, as indicated by an arrow 198, about the pin 192. The operation of the tool 10 will now be discussed with reference to Figures 3 through 8. Referring first to Figures 3a and 3b, the insertion of a band clamp 12 into the tool 10 is illustrated. With the pull up handle 116 and the cutoff handle 154 in their spring biased positions, the tension hold/release hook 110 is grasped by an operator and moved in the direction 126. Movement of the hook 110 in the direction 126 causes the tension hold/release link 106 to move in the direction 128. Thus, the tension pin 78 and the tension holding pin 92 are moved in their respective holes against their spring bias to form gaps G therebetween and the bottom surface 85 of the tension block 46 and the cutoff blade 86 which are at least slightly greater than the thickness of the band 13. The gaps G thus formed allow the band 13 to be inserted in the direction 128 into the tool 10. Due to the angle A between the linear axis 38 of the tensioning means 24 and the linear axis 40, the band 13 is maintained straight without the necessity of bending thereof around internal parts of the tool 10. Thus, tensioning of the band 13 and insertion thereof into the tool 10 is relatively easier than in prior art devices. Referring to Figures 4a, 4b and 4c the tool 10 is shown in the tensioning mode. The pull up handle 116 is pulled back-and-forth as indicated by the arrow 126 and an arrow 200 between the position as shown in Figure 4a and the position as shown in Figure 3a. As the handle 116 is moved in the direction 126, the tension hold/release hook 110 is not engaged with the tension hold/release link 106. As the handle 116 pivots about the pin 135, the connecting rod 32 is moved in a direction indicated by an arrow 202 as a result of the interconnection thereto by the pin 130. As can be seen in Figure 4b, movement of the rod 32 similarly causes movement of the push links 42 in the direction 202. Movement of the links 42 in the direction 202 is caused by the pin 66 engaging a front edge 250 of the slot 72 in the connecting rod 32. The pin 66 is held against the edge 250 by the support plunger 68 which is in turn pushed in the direction 202 by the storing device 26. As long as the tension in the band 13 does not overcome the recompression of the device 26 the pin 66 is held against the edge 250. In other words, the assembly 24 acts as a solid rod until the band 13 reaches the predetermined tension. Therefore, as the link 42 moves in the direction 202 the tension transfer lever 44 is forced to pivot in a clockwise direction as indicated by an arrow 206 about the pin 62 as a result of the interconnection therebetween with the link 42 by pin 58. As the pin 58 moves in the direction 202 it slides along the cam surface 190 of the tension holding hook 104 against the bias of the spring 194 and the hook 188 thereof is held out of the slot 204 in the connecting rod 32. Thus, an operator knows that the band 13 has not been tensioned the desired amount and further cycling of the handle 116 is required. Referring to figure 4c, as the link 42 moves in the direction 202, the transfer lever 44 pivots in the clockwise direction 206. Due to the interconnection between the lever 44 and the tension block 46 by the pin 52, the tension block 46 is moved in a direction indicated by an arrow 208. Movement of the tension block 46 in the direction 208 forces the tension pin 78 toward the edge 210 of the elongated slot 76 therein, and the band 13 is gripped between the pin 78 and the bottom surface 85 of the block 46. Thus as the handle 116 moves in the direction 126, the band 13 is moved in the direction 208 to increase the tension therein. As the band 13 is moved in the direction 208 by the pin 78 and the block 46, the pin 92 is moved toward the edge 212 of the elongated slot 94. Thus the band 13 is allowed to pass between the pin 92 and the cut-off blade 86. When the handle 116 is moved in the direction 200, the block 46 is moved in a direction indicated by an arrow 214. As the block 46 moves in the direction 214, tension in the band 13 causes the band 13 to also try to move in the direction 214. The tension in the band 13 and the bias of the spring 98 thus moves the pin 92 away from the edge 212 in the slot 94 and holds the band 13 from movement in the direction 214. Similarly, movement of the block 46 in the direction 214 causes the pin 78 to move against the bias of the spring 82 and away from the edge 210 in the slot 76, allowing the pin 78 to pass freely over the band 13. Therefore, the handle 116 is cycled in the direction 126 and 200 as described to gradually tension the band 13 around the shield 17. It is an advantage of the tool 10 that the handle 116 and lever 44 is used rather than toggles, as are found in the prior art. The handle 116 and the lever 44 provide a mechanical advantage over toggles allowing fewer cycles of the handle 116 to move the band farther than in a corresponding toggle tool. Although not shown, it is to be understood that by varying the length of the lever 44 about the pin 62, various mechanical advantages may be achieved. Additionally, the use of the force storing device 26 such as a precompressed spring allows the tool 10 to be smoother, easier to operate and more accurate than prior devices. Referring to Figures 5a and 5b, the band 13 has been pulled to the desired tension within the tool 10. When the desired tension is reached, the handle 116 is locked in the position as shown in Figure 5a. In the locked condition, the spring 142 (see Fig. 2a) is unable to return the handle 116 to the position shown in Figure 3a, and the operator knows that the desired tension has been reached. As best seen in Figure 5b, when the tension in the band 13, as indicated an arrow 216, exceeds the recompression of the storing device 26, the device 26 further compresses in a direction indicated by an arrow 218. Thus the support plunger 68 and the pin 66 also move in the direction 218 as the connecting rod 32 moves in the direction 202. Since the pin 58 is also connected to the push links 42, the pin 58 does not move in the direction 202 and does not ride along the cam surface 190 of the tension holding hook 104. Thus the hook 188 thereon enters the slot 204 on the connecting rod 32 to lock the handle 116 in the position as shown in Figures 5a and 5b. Referring to Figures 6a, 6b and 6c, the cut-off sequence is illustrated. Referring first to Figures 6a and 6b, the pull up handle 116 is in the uppermost locked position. The cut-off handle 154 pivots in a direction as indicated by an arrow 220 about pin 156 which moves the cut-off links 170 in a direction indicated by an arrow 222. Movement of the links 170 in the direction 222 causes the cut-off arm 174 to pivot clockwise about the pin 184. The clockwise rotation of the cut-off arm 174 moves the cut-off knife 180 in a direction indicated by an arrow 224. The cut-off knife 180 first contacts the buckle 15 and then bends and severs the band 13 therebetween and the cut-off blade 86, as will be subsequently described in greater detail. Simultaneously, the pin 178 contacts the tension holding hook 104 to push the hook 104 in the direction 222 and thus release the hook 188 from the slot 204 ( as shown in Fig. 6c) which will allow the pull up handle 116 to return to the extended position as shown in Figure 3a. Referring to Figures 7a and 7b, one embodiment of a cut-off arrangement is illustrated. Referring first to Figure 7b, the cut-off blade 86 and the cut-off knife 180 are shown in perspective. The cut-off blade 86 which is reversible within the tool 10, provides a flat surface 225 for cooperation with the tension holding pin 92 to hold the band 13 therebetween. A cutting and bending edge 226 is provided for cooperation with the knife 180a. As the knife 180a is pushed in the direction 224 by movement of the cut-off handle 154, a lower surface 228 thereof first contacts the buckle 15. Interaction between the lower surface 228, the buckle 15 and the upper surface 225 of the blade 86a causes the band 13 to be first bent and then severed. Due to an arcuate cutter 230 on the cut-off knife 180a, an arcuate tab 232 as shown in Figure 8a is formed. The length L of the tab 232 is controlled by the thickness of the buckle 15 and the vertical location of the arcuate cutting edge 230. As the buckle 15 is pushed in the direction 224 by the knife 180a, the band 13 is bent by the buckle 15 before being severed by the arcuate cutter 230. Referring to Figures 8a and 8b, an alternative cutting arrangement is illustrated. Referring first to Figure 8b, a cut-off blade 86b and a cut-off knife 180b are shown. The knife 180b has a flat surface 234 and a bending/cutting edge 236. The blade 86b has a stepped bottom surface 238 having a width W matching a width w of the bending/cutting edge 236. Thus as the knife 180b moves in the direction 224, the lower surface 238 comes into contact with the band 13 beyond the buckle 15. The band 13 is forced into the width w of the blade 86b by the bottom surface 238. When the shoulders 240 of the knife 180b come into contact with the extensions 242 of the blade 86b, the band 13 has been bent and severed into a tab 244 as shown in Fig. 8a. Thus the tab 244 is formed with a straight cut-off edge 246 and a pair of retention ears 248. The retention ears 248 help secure the band 13 to the buckle 15 to prevent loss of tension therein. Since it is important to the convenient use of the tool 10 to be able to tension the clamp 12 proximate the couple 14, the width of the tool 10 has been designed to be as close to the width of the band 13 as possible. Thus it is possible to place the tool 10 against the flange 18 and have the clamp 12 installed with a minimum amount of space therebetween. Similarly, the tool 10 has been designed for ease of operation by using the lever 44 rather than toggles as is found in the prior art. Finally, the angular relationship between the tensioning assembly and the head 36 provides a tool that is easy to load and that applies more of the work force to tensioning the band 13 than in previous devices. Figures 9 and 10 illustrate embodiments of a lock for use with a band clamp in which the lock provides improved strength characteristics relative to known locks in which the lock is formed by bending the band portion of the band clamp to create a locking surface that engages an exterior surface of a buckle portion of the band clamp. In order to describe the lock of the present invention, it is believed to be useful to first describe the band clamp with which the lock is employed. With reference to Figures 9 and 10, the band clamp 300 includes a buckle 302 and a band 304 with a first end 306 that is operatively attached to the buckle 302 and a second end 308 that can be wrapped about an object and then engaged to the buckle 302. The band 304 is further defined by a first lateral edge 310a that is substantially parallel to a second lateral edge 310b. A longitudinal axis 312 extends from the first end 306 to the second end 308 and is substantially perpendicular to a line extending from a first point on the first lateral edge 310a to second point on the second lateral edge 310b that is the same distance from the first end 306 or the second end 308 as the first point. The band 304 further includes a first face 314a that is substantially parallel to a second face 314b. The band 304 is made of a material that can be wrapped about an object and then bent, deformed or otherwise processed to lock the band 304 to the buckle 302. Typically, the band 304 is made from a metal material, such as steel or aluminum. However, other materials, such as plastic, can also be used. The buckle 302 can be generally described as an open-ended sleeve-like structure with a lower member 318 that is positioned substantially adjacent to the object about which the band 304 is wrapped and an upper member 320 that is separated from the object of interest by the lower member 318. The lower member 318 and the upper member 320 define an interior surface 322 that, in turn, defines a passageway 324 for receiving the band 304 after it has been wrapped about an object. The lower member 318 and the upper member 320 also define an exterior surface that includes an exterior side surface 326, a first exterior end surface 328a, and a second exterior end surface 328b. The buckle 302, like the band 304, is typically made of a metal material, such as steel or aluminum, but other materials, such as plastic, can also be employed. Having described the band clamp 300, the lock of the present invention is now described with reference to Figs. 9 and 10, characteristic of each embodiment of the lock is that a lateral cross-section of a locking surface 332 that is established in a portion of the second end 308 of the band 304 that emerges from the buckle 302 after the band 304 has been passed through the passageway 324 is that a first point 336 on the first lateral edge 310a is a different distance from the lower member 318 of the buckle 302 than an intermediate point 338 on the band 304 that is located in between the first point 336 and a second point 340 on the second lateral edge 310b. The locking surface 332 engages the first exterior end surface 328a of the buckle 302 to prevent the band 304 from being pulled back through the passageway 324 of the buckle 302 as well as exhibiting improved strength characteristics relative to known band clamp locks in which the band is bent, deformed, or otherwise processed to create a locking surface that engages the exterior of a buckle. Figures 9a-9d and 10a-10d illustrate two embodiments of the lock of the present invention. In these embodiments of the lock, the lateral cross-section of the locking surface 332 is such that the intermediate point 338 that is located in between the first point 336 on the first lateral edge 310a and the second point 340 on the second lateral edge 310b is a greater distance from the lower member 318 of the buckle 302 than the first point 336 on the first lateral edge 310a. Further, the intermediate point 338 on the band 304 is a greater distance from the lower member 318 of the buckle 302 than the second point 340 on the second lateral edge 310b. In addition, the locking surface 332 is further characterized by the distance of the first point 336 on the first lateral edge 310a to the lower member 318 of the buckle 302 and the distance of the second point 340 on the second lateral edge 310b to the lower member 318 of the buckle 302 being substantially equal. Further, the locking surface is established by bending the first and second lateral edges 310a, 310b substantially parallel to the longitudinal axis 312 of the band 304. Further, in these embodiments of the lock, the locking surface 332 comprises an intermediate edge 360 which is formed by cutting an intermediate portion 334 of the band 304 that emerges from the buckle 302 after the band 304 has been passed through the passageway 324. Particularly, the intermediate edge 360 is a surface intermediate to the first face 314a and the second face 314b of the band 304 and is formed by cutting the band 304 traverse to the longitudinal axis 312 from a first internal cutting point 362a to a second internal cutting point 362b, which is substantially opposite to the first internal cutting point 362a relative to the longitudinal axis 312. The locking surface 332 is formed by bending, deforming or otherwise processing the intermediate edge 360. The lock is established by engaging the intermediate edge 360 and the first exterior end surface 328a of the buckle 302. These embodiments of the lock can be further characterized by the lateral cross-section of the locking surface 332 being substantially Ω-shaped. Further, the intermediate edge 360 is substantially even with upper member 320 of the buckle 302. In addition to exhibiting strength characteristics, these embodiments are formed in such a way as to reduce the probability that the integrity of the lock will be compromised. Particularly, in these embodiments of the lock, the exposed edges are reduced to reduce the chances that the lock will defeated because of snagging. An additional advantage of these embodiments of the lock is that, due to the surface in between the first and second lateral edges 310a, 310b being displaced relative to the lower member 318 of the buckle 302 rather than the first and second lateral edges 310a, 310b, it allows a banding tool to be designed which can be used to form the lock for various band and buckle widths. With reference to Figures 10a-10d, in this embodiment of the lock, the exterior surface of the buckle 302 that engages the locking surface 334 further comprises a lock cover 366 to protect the locking surface 334 against tampering. The lock cover 366 comprises a cover exterior surface 368, a cover interior surface 370, a first cover end surface 372 and a second cover end surface 374, a first cover side surface 376, and a second cover side surface 378. Particularly, the lock cover 366 extends from the upper member 320 and over the portion of the band 304 that emerges from the buckle 302 after the band 304 has been passed through the passageway 324. The lateral cross-section of the lock cover 366 is substantially similar to the lateral cross-section of the locking surface 332 being covered. In this embodiment of the lock, the lateral cross-section of the cover exterior surface 368 is substantially Ω-shaped. In addition to providing protection for the lock, the lock cover 366 provides a reference point for the banding tool that is used to form the lock. Particularly, when the locking surface 332 is formed, the intermediate edge 360 of the locking surface 334 conforms with the cover interior surface 370 of the lock cover 366. The lock is established by engaging the intermediate edge 360 of the locking surface 334 and the portion of the first exterior end surface 328a of the buckle 302 which is left exposed by the lock cover 366. Having described embodiments of the lock of the present invention, the method of forming the various embodiments of the lock illustrated in Figures 9 and 10 and the tools for forming these locks will now be described. It is a characteristic of each embodiment of the lock that the locking surface 332 is established by shaping the portion of the second end 308 of the band 304 that emerges from the buckle 302 after being passed through the passageway 324, so that if the locking surface 332 is viewed in a lateral cross-section, the first point 336 on the first lateral edge 310a is a different distance from the lower member 318 of the buckle 302 than the intermediate point 338 located in between the first point 336 and the second point 340 on the second lateral edge 310b. The locking surface 332 can then engage the first exterior end surface 328a of the buckle 302 to prevent the band 304 from being pulled back through the passageway 324 of the buckle 302 as well as exhibits improved strength characteristics relative to known band clamp locks in which the band is shaped to create a locking surface that engages the exterior of the buckle. Figures 9a-9d and 10a-10d illustrate two embodiments of the lock of the present invention. In these embodiments of the lock, the locking surface 332 is formed by shaping the portion of the second end 308 of the band 304 that emerges from the buckle 302 so that if the locking surface 332 is viewed in lateral cross-section, the intermediate point 338 on the band 304 is a greater distance from the lower member 318 of the buckle 302 than the first point 336 and the second point 340. Further, in the lateral cross-section, the distance of the first point 336 on the first lateral edge 310a from the lower member 318 of the buckle 302 and the distance of the second point 340 from the lower member 318 are substantially equal. Stated another way, the lateral cross-section of the locking surface 332 is substantially Omega-shaped. Further, the portion of the band 304 is bent, deformed or otherwise processed to cause the intermediate edge 360 to be substantially even with the upper member 320 of the buckle 302. As before, the lock is created in a manner that largely circumvents any need to release tension in the band and relative rotation between the band and the clamped object and the thinning due to rotation. One way to form the embodiment of the lock referred to in Figures 9a-9d is to use the Ω-knife 404 and Ω-blade 406 shown in Figures 11a-11d with the banding tool previously described. The Ω-knife 404 includes a first leg 408a, a second leg 408b, a buckle contact surface 410, band contact surface 412, and a first cutting edge 414 for cooperating with the Ω-blade 406 to produce the lock and sever excess band. The Ω-blade 406 includes a tongue 416 and a second cutting edge 418 for cooperating with the Ω-knife 404 to form the lock and trim any excess portion of the band 304. With the Ω-knife 404 and Ω-blade 406 installed in the tool and with the band 304 appropriately tensioned by the tool, formation of the locking surface 332 commences with the Ω-knife 404 being displaced towards the Ω-blade 406 by the movement of the cut-off handle 154. As the Ω-knife 404 is displaced, the buckle contact surface comes into contact with the upper member 320 of the buckle 302 and the first and second legs 408a, 408b come into contact with the band 304. Further displacement of the Ω-knife 404 towards the Ω-blade 406 serves to form the locking surface 332 and sever any excess portion of the band 304. Specifically, further displacement of the Ω-knife 404 results in the first and second legs 408a, 408b of the Ω-knife 404 cooperating with the tongue 416 to form the locking surface 332 by displacing the portion of the band 304 located intermediate the first and second lateral edges 310a, 310b to be bent away from the lower member 318 of the buckle 302 in the characteristic Ω-shape. Also as a result of the bending the portion of the band 304 immediately adjacent to the first exterior end surface 328a of the buckle 302 is cut from the first internal cutting point 362a to the second internal cutting point 362b to form the intermediate edge 360. This cut is caused by the bending of this portion of the band 304 forcing the first face 314a of the band 304 to contact the band cutting edge 396. The band cutting edge 396 is the interface of the interior surface 322 and upper member 320 of the buckle 302. The lock is now formed by the engagement of the locking surface 332 to the buckle 302 and more specifically, by the engagement between the intermediate edge 360 of the locking surface 332 and the first exterior end surface 328a of the buckle 302. One way to form the embodiment of the lock referred to in Figures 10a-10d is to use, in the previously described banding tool, the Ω-knife 404 and Ω-blade 406 shown in Figures 11a-11d with the appropriate modifications to accommodate the lock cover 366. Particularly, the Ω-knife 404 is modified so that it substantially corresponds to the cross-sectional shape of the lock cover 366. When in operation the Ω-knife contacts the lock cover 366 as well as the upper member 320 of the buckle 302. In all other respects the use of the Ω-knife 404 and Ω-blade 406 in the banding tool to form the lock illustrated in Figures 10a-10d is identical to that previously described for forming the lock shown in Figures 9a-9d Also, the lock is made in a fashion that largely circumvents the need to release tension in the band and relative rotation between the band and the clamped object and hence the thinning associated with rotation.

Claims: A band clamp (300), comprising: a buckle (302) having a longitudinally extending passageway (324) for receiving a band (304), said passageway (324) having an entrance and an exit, said exit being defined by an edge of said buckle (302); said band (304) having a first lateral edge (310a), a second lateral edge (310b), a first end (306) operatively attached to said buckle (302) and a second end (308) for wrapping about an object and for inserting into said passageway (324); wherein at least a portion of said second end (308) of said band (304) extends through said passageway (324) and beyond said exit and said second end (308) of said band (304) is cut for forming a lock between said band (304) and said buckle (302), said band clamp being characterized in that: said cut begins at a first point (362a) that is located between said first lateral edge (310a) and said second lateral edge (310b) and terminates at a second point (362b) that is different from said first point (362a) and is located in between said first lateral edge (310a) and said second lateral edge (310b). A band clamp (300) according to claim 1, wherein: said buckle (302) has a lower surface for positioning adjacent to an object and an upper surface spaced from the lower surface and in which said upper surface of said buckle (302) includes a cover (366) for protecting a locking surface (332) formed from said band (304). A band clamp (300) according to claim 2, wherein: said locking surface (332) includes a surface (360) that is located between a first face (314a) and a second face (314b) of said band (304) for contacting an exterior surface (328a) of said buckle (302). A band clamp according to claim 2, wherein: said locking surface (332) is defined using a first point (336) and a second point (340) and in which a cross-section of said locking surface (332) that extends from said first point (336) to said second point (340) has a substantially Ω-shape. A method for establishing a lock between a band and a buckle, comprising: providing a buckle (302) having a longitudinally extending passageway (324) for receiving a band, said passageway (324) having an entrance and an exit, said exit being defined by an edge of said buckle (302); providing a band (304) having a first lateral edge (310a), a second lateral edge (310b), a first end (306) operatively attached to said buckle (302), and a second end (308) for wrapping about an object and inserting into said passageway (324); wrapping said second end (308) of said band (304) about said object; inserting said second end (308) of said band (304) through said passageway (324) so that at least a portion of said second end (308) extends beyond said exit; and cutting said second end (308) of said band (304) so that a lock can be formed between said band (304) and said buckle (302), characterised in that: said cutting begins at a first point (362a) that is located in between said first lateral edge (310a) and said second lateral edge (310b) and terminates at a second point (362b) that is different to said first point (362a) and is located in between said first lateral edge (310a) and said second lateral edge (310b).

Inventors: MARELIN MIKLOS B, MARELIN, MIKLOS B.
Applicants: BAND IT IDEX INC, BAND-IT-IDEX, INC.
Application year: 1993
Main classification: B65B13
IPC codes: B25B25, B65B13