Abstract:
A crimping device for securing a seal member onto overlapped end portions of a strap material includes at least a tool head, operating and stationary handles, two rows of crimping elements having at least a pair of shears and oppositely situated pair of jaws extended between the pair of shears. The crimping elements may be disposed in the tool head and connected with the handles so that at least one row of crimping elements crimps a seal while at least one row is idle when the handles move away from each other. In an embodiment, the handles can make an inward stroke only when a full jaw-closing outward crimping stroke is completed. At least one row of crimping elements crimps the seal with an inward movement of the handles while at least one previously actuated row of crimping elements is not involved in closing the seal.

Description:
FIELD 
     The present invention relates generally to banding equipment, and more particularly to crimping devices. 
     BACKGROUND 
     The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions. 
     Banding tools are used to secure articles in a bundle, or to bind packages. After a band is tightened, the band is held in position by a metal seal that is crimped on the band. The band or strap material is typically metal or plastic. While metallic strapping has been used for banding all kinds of packages for a number of years, only recently has interest been shown in wide—more than ¾″ (19 mm)—and thick—more than 3/64″ (1.2 mm)—extruded non-metallic strapping. These straps that are more than ¾″ (19 mm) wide and more than 3/64″ (1.2 mm) thick have a very high tensile strength and resist dimensional change when placed around an object and tensioned. 
     Crimping of a metal seal on straps that are more than ¾″ (19 mm) wide and more than 3/64″ (1.2 mm) thick requires a substantial amount of force, and the current specification recognizes that it is highly desirable to reduce the amount of force necessary to crimp straps, thereby easing the effort necessary to operate the banding tool. 
     Some prior art devices may employ a two phase operation with one idle stroke and one working stroke that completes crimping action with an inward movement of the handles. There are also prior art two stroke operation devices that close the seal on both outward and inward crimping strokes but all rows of jaws are simultaneously involved in closing the seal and require energy for actuation. The prior art devices also have an action such that the operator can remove the tool from the strap even if the sealing action has not been completed so that there is a possibility that the incomplete seal may be weaker than specified or be otherwise imperfect. 
     SUMMARY OF THE INVENTION 
     A two stroke crimping device for securing a seal member onto overlapped end portions of strap material that requires less effort by the operator than a single stroke device is provided. 
     In an embodiment, the crimping device may include a tool head, pair of handles, at least two rows of crimping elements, which include at least a pair of shears and an oppositely situated pair of jaws extended between the pair of shear elements. In this specification, the terms jaws and crimping elements may be substituted for one another wherever they appear and wherever the substitution results in a sentence that makes sense to obtain different embodiments and/or statements of different scopes. 
     In an embodiment, the crimping tool includes at least two pairs of jaws. At least one pair of jaws opens and closes with the movement of one of the handles, while the other handle may remain stationary. As one handle moves away from the other handle, the first pair of jaws opens and as the handle moves towards the other handle the first pair of jaws closes. The other pair of jaws has two mechanical biases. One mechanical bias is so that when one of the two handles is moved in one direction, one pair of jaws closes, and when the same handle is moved in the opposite direction the other pair of jaws closes. 
     In an embodiment, the crimping tool includes at least a stationery handle mounted on the tool head and the operating handle is connected to at least two pairs of jaws (having crimping elements). One row of jaws is connected through a pair of linkages to the operating handle, and another row of jaws (having crimping elements) is connected to the operating handle through a pair of lock arms, the lever, and the second pair of linkages. These two connections of the jaws to the handle allow the handle to actuate each row of crimping elements independently. 
     One of the rows of crimping elements (a first pair of jaws is a part of the first row of crimping elements) crimps a seal during an outward stroke of the handles, as the handles move away from each other, and while the handles move away from each other, the second row of jaws does not move. At the end of outward stroke a pair of lock arms locks the lever. In an embodiment, the handles can make an inward stroke only after a full jaw-closing outward crimping stroke is completed. The first row of crimping elements move oppositely in a reverse direction during the inward movement of the handles, i.e. while the second row of jaws (crimping elements) crimps the seal the first row of jaws (crimping elements) releases the seal. 
     In an embodiment, a spring reopens the second row of jaws so as to free the seal and to ready jaws for the next operation only if the inward stroke has been completed. In this embodiment, the handle of the crimping device can make an inward stroke only when a full jaw-closing outward crimping stroke is completed. Not allowing the next operation until the inward stroke is complete is facilitated by a shaft being connected to a pair of lock arms, which unlocks the lever at the end of the inward stroke, and allows a spring to return the lever to an initial position in which the jaws are again open. 
     The result of closing each pair of crimping elements on different strokes is that the lever moves only one pair of jaws and the force needed to crimp the seal is divided between inward and outward strokes so that the operator feels as though less effort needs to be applied (by the operator) during the working cycle as a result of the reduction of force that needs to be applied to the handles to operate the two stroke crimping device. The spring of the crimping devices reopens the jaws and frees the seal only after the inward stroke has been completed and the second row of jaws (crimping elements) has finished the crimping operation, so the device is ready for the next cycle. The crimping device keeps all jaws open and the handles next to each other during the loading operation, which facilitates easy placing of the crimping device on the seal. Since all rows of jaws are open and the handles are next to each other when the operation cycle starts, it is easy to place the crimping device on the steel seal of the strap, which is tensioned and placed around the object. 
     Any of the above embodiments may be used alone or together with one another in any combination. Inventions encompassed within this specification may also include embodiments that are only partially mentioned or alluded to or are not mentioned or alluded to at all in this brief summary or in the abstract. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following drawings like reference numbers are used to refer to like elements. Although the following figures depict various examples of the invention, the invention is not limited to the examples depicted in the figures. 
         FIG. 1  is a perspective view of an embodiment of a two stroke crimping device in the initial position; 
         FIG. 2  is an exploded view of an embodiment of the crimping tool of  FIG. 1 ; 
         FIG. 3   a  is a view of an embodiment of the first crimping element in the initial position. For better view, parts of the second crimping element are missing. 
         FIG. 3   b  is a view of an embodiment of the first crimping element in the intermediate position of the operating handle&#39;s outward stroke. 
         FIG. 3   c  is a view of an embodiment of the first crimping element at the end of the operating handle&#39;s outward stroke. 
         FIG. 3   d  is a view of an embodiment of the first crimping element in the intermediate position of the operating handle&#39;s inward stroke. 
         FIG. 3   e  is a view of an embodiment of the first crimping element in the initial position of unlock operation. 
         FIG. 3   f  is a view of an embodiment of the first crimping element at the end of operating handle&#39;s inward stroke—(unlock operation in progress). 
         FIG. 3   g  is a view of an embodiment of the first crimping element at the end of the operating handle&#39;s inward stroke and at the end of unlock operation—initial position for the next cycle. 
         FIG. 4   a  is a cross-sectional view of an embodiment of the second crimping element in the initial position. For better view, parts of the first crimping element are missing. 
         FIG. 4   b  is a cross-sectional view of an embodiment of the second crimping element in the intermediate position of the of the operating handle&#39;s outward stroke. 
         FIG. 4   c  is a cross-sectional view of an embodiment of the second crimping element at the end of the operating handle&#39;s outward stroke. 
         FIG. 4   d  is a cross-sectional view of an embodiment of the second crimping element in the intermediate position of the operating handle&#39;s inward stroke. 
         FIG. 4   e  is a cross-sectional view of an embodiment of the second crimping element in the position of initiation of unlock operation. 
         FIG. 4   f  is a cross-sectional view of an embodiment of the second crimping element at the end of the operating handle&#39;s inward stroke—unlock operation in progress. 
         FIG. 4   g  is a cross-sectional view of an embodiment of the second crimping element at the end of the operating handle&#39;s inward stroke at the end of unlock operation—initial position for the next cycle. 
         FIG. 5   a - g  show an embodiment of collapsible arm for every position of the second crimping element shown on  FIG. 4   a - g  respectively. 
     
    
    
     DETAILED DESCRIPTION 
     Although various embodiments of the invention may have been motivated by various deficiencies with the prior art, which may be discussed or alluded to in one or more places in the specification, the embodiments of the invention do not necessarily address any of these deficiencies. In other words, different embodiments of the invention may address different deficiencies that may be discussed in the specification. Some embodiments may only partially address some deficiencies or just one deficiency that may be discussed in the specification, and some embodiments may not address any of these deficiencies. 
     Referring first to  FIG. 1  and  FIG. 2 , which show a crimping device constructed with a tool head  1  ( FIG. 1 ), stationary handle  2  mounted on the housing  3 , an operating handle  4  pivotally mounted on the housing  3  by a central pin  5 , first crimping element  6  and second crimping element  7 . First crimping element  6  includes at least a first an oppositely situated pair of jaws  62  pivotally held in place and sandwiched between a pair of shears  61 . Second crimping element  7  includes at least a pair of shears  71  and an oppositely situated pair of jaws  72  pivotally held in place and sandwiched between a pair of shears  71 . Both first and second crimping elements are secured in a housing  3  by shafts  8 . Housing  3  has surface  31 , which is discussed below in conjunction with  FIGS. 4   e  and  4   f .  FIGS. 1 and 2  each show two views of the head  41  of operating handle  4 . 
     Pins  63  connect the head  41  of operating handle  4  to first crimping element  6  by linkages  64  and  65 . Operating handle  4  acts as a lever to directly cause linkages  64  and  65  to move as operating handle  4  moves. Pins  73  connect lever  9  to the second crimping element  7  by linkages  74  and  75 . Moving lever  9  causes linkages  74  and  75  to move. Lever  9  is pivotally mounted on the housing  3  by a central pin  5 . Two lock arms  91  and  92  are situated inside the head  41  of operating handle  4  and are connected to each other with lock pin  93  and also connected to the head  41  of operating handle  4  by pin  95 , via lock arm  91  being pivotally mounted on pin  95 , which is mounted on the head  41  of operating handle  4 . Additionally, lock arms  91  and  92  are connected with lever  9  through pin  97 , such that lock arm  91  is pivotally mounted on pin  97 , which is mounted on lever  9 . At the same time, lever  9  is connected with the head  41  of operating handle  4  through pins  93 ,  95 , and  97  and lock arms  91  and  92 . Lock spring  94  is located inside the lock arm  92  and is mounted on pin  95 . In an embodiment, lock spring  94  is a coil spring. One of two ends of lock spring  94  presses on the head  41  of operating handle  4 . Another end of the lock spring  94  pushes lock arm  92  against one end of lock arm  91  (the end of lock arm  91  that has pin  93  is the end that lock spring  94  pushes lock arm  92  against). Initially (that is in  FIGS. 4   a - e ), as a result of the mechanical bias of lock spring  94  creates clockwise directional torque on lock arm  92  about pin  93 . Main spring  96  is mounted on the central pin  5  and is located inside the lever  9 . Main spring  96  creates counterclockwise directional torque on lever  9  against the head  41  of operating handle  4  as shown on  FIG. 4   a - e.    
     The operation of the crimping device is best understood by referring to  FIGS. 3   a - g  and  FIGS. 4   a - g .  FIGS. 3   a - g  are views of the first crimping element shown in different positions of the operating handle  4 .  FIGS. 4   a - g  is cross-sectional view of the second crimping element shown in different positions of the operating handle  4 . The sequence of events represented by  FIGS. 3   a - g  occur simultaneously with the sequence of events represented by  FIGS. 4   a - g  and are characterized by the same position of the handle. That is, each of the positions of  FIGS. 3   a - g  occurs at the same handle position as the corresponding one of  FIGS. 4   a - g , respectively. It should be noted that due to the fact that jaws  62  and  72  are open and handles  2  and  4  are next to each other in the beginning of the operation cycle, it is easy to position the crimping device on the steel seal after strap is tensioned around the object. 
     The operator begins the operation cycle with the crimping device positioned on the seal, as shown on  FIGS. 3   a  and  4   a . After placing the crimping device on the seal, the operator pivots operating handle  4  about pin  5  upwards while holding the stationary handle  2  (or rotates operating handle  4  away from stationary handle  2 ). The rotating of operating handle  4  away from stationary handle  2  may be referred to as the “outward crimping stroke,” and the rotating of operating handle  4  towards stationary handle  2  may be referred to as the “inward crimping stroke.” 
     During the outward crimping stroke, jaws  62  of the first crimping element  6  cut the seal along with two ends of the tensioned strap inside the seal as jaws  62  are directly connected with the head  41  of operating handle  4  through pins  63  by linkages  64  and  65  as shown on  FIG. 3   b . At the same time, jaws  72  of second crimping element  7  and lever  9  remain stationary while the position of lock arms  91  and  92  changes as shown on  FIGS. 4   a - c  and  FIGS. 5   a - c.    
     During the outward crimping stroke, main spring  96  becomes more and more compressed as the operating handle  4  is moved further from stationary handle  2 . During the outward crimping stroke, main spring  96  pushes the head  41  of operating handle  4  away from linkage  74  with a larger and larger force as main spring  96  is compressed, but the force from main spring  96  is easily overcome by the operator of operating handle  4 , resulting in main spring  96  becoming more compressed at the end of the outward crimping stroke than at any other time during the two stroke crimping process, and main spring  96  remains in this compressed state throughout the remainder of the outward crimping stroke and much of the inward crimping stroke. During the outward crimping, the result of main spring  96  pushing linkage  74  away from operating handle  4  is a downward force on pin  73 , which pulls on the end of lever  9  that has pin  73 , creating a torque in the counterclockwise direction (with respect to pin  5 ) on lever  9 , which holds pair of jaws  72  in an open position. 
     While in the position of  FIGS. 4   a  and  5   a , lock arms  91  and  92  form a collapsible arm  98  that is folded to the greatest extent that the arm formed by lock arms  91  and  92  is folded during the two stroke crimping. In  FIG. 5   a  lock arms  91  and  92  form an acute angle A facing rightwards. As the outward stroke crimping progresses, the angle A between lock arms  91  and  92  increases. Initially the collapsible arm  98  formed by lock arms  91  and  92  straightens until a position somewhere between that shown in  FIGS. 5   b  and  5   c . In  FIGS. 5   c - 5   e , the angle B made by lock arms  91  and  92  is an oblique angle that faces the opposite direction, with respect to operating handle  4 , as the angle A of  FIGS. 5   a  and  5   b . While in the position shown in  FIG. 4   a , lock spring  94  pushes lock arm  92  to rotate clockwise about pin  93 . 
     While in the position of  FIG. 5   c , since lock arm  91  has changed the angle A to angle B that lock arm  91  makes with lock arm  92 , now collapsible arm  98  pushes on lever  9  creating a torque in a clockwise direction, which would tend to close jaws  72 . However, main spring  96  still pushes lever  9  to rotate in a counterclockwise direction working against lock spring  94 , and since main spring  96  is stronger than lock spring  94 , the net result is a force pushing lever  9  in a counter clockwise direction holding jaws  72  open. 
     At the end of the outward crimping stroke, when jaws  62  of the first crimping element  6  finish the strap crimping operation (which may result in cutting the seal), as shown on  FIG. 3   c , the lock spring  94 , via lock arm  92 , moves the pin  93  to lock arm  92 &#39;s end position where lock arm  92  is pressed (by lock spring  94 ) against the surface  411  ( FIG. 4   b ) of the head  41  of the operating handle  4 , as shown on  FIG. 4   c . Lock spring  94  holds the collapsible arm  98  formed by lock arms  91  and  92  in the angle B, mentioned above, that faces the opposite direction as the angle A made by lock arms  91  and  92  shown in  FIGS. 4   a  and  4   b.    
     The inward crimping stroke begins after the outward cycle is finalized and the operator begins moving the operating handle  4  back toward the stationary handle  2 , as shown in  FIG. 3   d  and  FIG. 4   d.    
     During the inward crimping stroke, jaws  72  of the second crimping element  7  make the second cut of the seal while jaws  62  of first crimping element  6  are opening up and releasing the seal ( FIG. 3   d  and  FIG. 3   e ). Lever  9  moves with the head  41  of operating handle  4  without compressing the lock spring  94 . After loading main spring  96 , lock spring  94  remains uncompressed and main spring  96  remains compressed until lock arms  91  and  92  unlock. During the inward crimping stroke, lock arms  91  and  92  remain locked in place as a result of lock spring  94  pushing pin  93  into surface  411  of the head  41  of operating handle  4  until just after the position of  FIG. 4   e . As a result of lock arms  91  and  92  being locked in position, the combination of lock arms  91  and  92  act as one collapsible arm  98 , such that as the inward stroke progresses from the position of  FIG. 4   c  until the position of  FIG. 4   e , and the combination of lock arms  91  and  92  transfers the force exerted by the operator from operating handle  4 , via the combination of lock arms  91  and  92 , to the side of lever  9  having pin  97 , causing lever  9  to rotate clockwise about pin  5 , thereby closing jaws  72 . At the end of the inward stroke ( FIG. 4   e ), although the force from handle  4  would still push lock arm  92  into lock arm  91  (and thereby would push jaws  72  closed), pin  93  engages surface  31  ( FIGS. 2 ,  4   e  and  4   f ) of the housing  3  that is shaped to be sloped downward towards the right in  FIG. 4   d , so that a component of the downward force on pin  93  is perpendicular to surface  31 , but pointing to the right in  FIG. 4   e , which unlocks lock arms  91  and  92  (collapses collapsible arm  98 ). Consequently, since the torque of the lock spring  94  is inferior to the torque of the main spring  96  and, at a certain point, ( FIG. 40  the main spring  96  rotates the lever  9  counterclockwise and opens up jaws  72  of the second crimping element  7 , until main spring  96 , lever  9 , lock arm  91  and lock arm  92  return to essentially the initial position  FIG. 4   g  (it may be necessary to further close operating handle  4 , slightly, to fully return to the initial open position of  FIG. 4   g ). The further closing of the operating handle  4  and stationary handle  2  also returns jaws  62  of first crimping element  6  to the initial open position as well ( FIG. 3   g ). After the crimping device has been returned to its initial position (as shown in  FIGS. 3   g  and  4   g ), the crimping device can be taken away from the secured seal and ready to the next operating cycle and secure another seal in another location. 
     A feature of the crimping device is that it requires less force to be applied by the operator than were both rows of crimping elements closed simultaneously due to presence of an idle row of jaws on each stroke of working cycle. Another feature of the crimping device is all full jaw-closing crimping strokes are ensured to be completed. Another feature of the crimping device is that jaws automatically reopen at the end of the crimping operation. 
     Each embodiment disclosed herein may be used or otherwise combined with any of the other embodiments disclosed. Any element of any embodiment may be used in any embodiment. 
     Although the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the invention. In addition, modifications may be made without departing from the essential teachings of the invention.