Abstract:
The present invention relates to a handheld electrical binding apparatus, primarily comprising an improved tensioning unit and a melting and cutting unit that cooperates with a control unit to provide maximum convenience in use. The apparatus of the invention can efficiently stretch binding straps and then melt and cut it, achieving the purpose of securing a package with bands.

Description:
SUMMARY OF THE INVENTION 
     A small conventional electrical binding apparatus generally comprises a motor to drive a transmission mechanism and to govern a tensioning and a melting device to proceed the operations of stretching, and melting. With such an apparatus, a package can be held with thermoplastic straps for handling or transportation purposes. One of such apparatuses is disclosed in the U.S. patent application Ser. No. 09/071,882 U.S. Pat. No. 6,003,578 filed by the same applicant of this present invention. The invention improves the binding apparatus to enable the routing of binding straps and the adjustment of tension to be done in an easy way. Further, the binding apparatus can automatically conduct the stretching, wrapping, melting, and sealing operations. The apparatus according to the invention has better performance as well as the enhancement of wrapping efficiency in comparison with a conventional one. 
     Now the structure and features of the invention will be described in detail with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective assembly view of a handheld binding apparatus according to the invention. 
     FIG. 2 is a plan front view of the apparatus of the invention. 
     FIG. 3 is a plan top view of the apparatus of the invention. 
     FIG. 4 is a plan right view of the apparatus of the invention. 
     FIG. 5 is a plan rear view of the apparatus of the invention. 
     FIG. 6 is a plan view schematically showing the movement of the tensioning unit of FIG. 2 when it is lifted. 
     FIG. 7 is a plan view schematically showing the movement of the tensioning unit of FIG. 5 when it rises. 
     FIG. 8 is a plan view schematically illustrating the movement of the melting unit of FIG. 2 when it descends. 
     FIG. 9 is a right-side partial sectional view of the apparatus of FIG. 8. 
     FIG. 10 is an exploded view partially showing the structure of the tensioning unit according to the invention. 
     FIG. 11 is an assembly perspective view of the apparatus shown in FIG. 10. 
     FIG. 12 is a schematic view illustrating the planar movement of the left-side structure of the apparatus according to the invention. 
     FIG. 13 is a partial cross sectional plan view of the apparatus of the invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     For a better understanding, the apparatus of the invention is shown in the accompanying drawings with the housing detached to expose the internal structure of the apparatus. Referring to FIGS. 1 through 5, the invention comprises a motor (1) disposed on the lower portion of the binding apparatus as a driving unit. The motor drives a transmission axle (11) and a worm gear (12) to govern a tensioning unit (2) and a melting unit (4), in cooperation with bearings on the transmission axle. The main part of the apparatus is enclosed in a housing (14) with a handle (13) extending to the outside, a switch (15) disposed on the top, and a manual melting lever (16) pivotally attached to the housing. A base (17) extends beneath the tensioning unit (2) and the melting unit (4). Arranged under the tensioning unit (2) is a slant frictional board (18) on the inner and upper side of which a micro switch (19) is attached. 
     The tensioning unit (2) includes a driving board (21) and a driven board (24). As shown in FIGS. 10 and 11, the driving board (21) is provided on one side with gears (22) engaged with the transmission mechanism. The driving board (21) is coupled with the driven board (24) by extending a shaft (23) of the former into a sleeve (25) of the latter. The cross-shaped shaft (221) of the gear (22) is inserted with clearance fit into the openings (261) formed on the large and the small friction wheel (26) and (26&#39;) of the driven board (24). The driving board (21) is connected at the upper and side corner with a link (27), which further is coupled at the other end with a driven plate (28). The driven plate (28) is pivotally attached at the middle to a base and abuts against the inner end of the handle (13) at the free end. When handle (13) is urged, the driven plate (28) is moved downwardly. The driven plate (28) is provided with a notch (281) disposed on the upper corner near the end thereof connected to the link (27), which notch is configured to be locked by a stop block (80). As shown in FIG. 13, the stop block (80) is connected at one end to the base of the apparatus and a spring (81) that biases the stop block (80) outwardly. The stop block (80) is equipped on the upper portion with a L-shaped seat (82) that has an elongated opening (83) formed on the top to receive a post (131) disposed on the lower portion of the handle (13). When the handle is lifted at the end, the post (131) urges the stop block (80) to escape from the notch (281) of the driven plate (28) and to move sideways into the base by the L-shaped seat (82). As a result, the driven plate (28) can be activated by a force exerted on the outer end thereof to urge the tensioning unit to rotate. 
     A swivel rod (30) is pivotally arranged between the tensioning unit (2) and the melting unit (4). The lower end of the swivel rod (30) is situated by the rear end of the frictional board (18) and the upper end is in touch with a push rod (31) inwardly extending from an adjustment block (32). The adjustment block (32) is connected at the outer end with a spring adjustment knob (321). Adjusting the spring force can change the contact pressure on the swivel rod (30) exerted by the push rod (31). The swivel rod (30) is further provided on one side with an extension rod (33). The extension rod (33) is coupled at the rear end with a strut (36) that extends into an opening (161) on the lower end of the manual melting lever (16). The extension rod (33) is furnished with a stationary block (34), and a ring (35), and a spring (37) disposed between the stationary block (34) and the adjustment block (32). A pin (341) extends from the stationary block (34) and stops on a recessed portion of the swivel rod (30). 
     The melting unit (4) includes a melting base (41). The melting base (41) is connected at the inner end to the transmission mechanism to be driven to move to-and-fro. The melting base (41) is further pivotally joined at the upper end with a connection block (42) so that when it is driven to move it acts like a suspender. The connection block (42) is pivotally linked at the upper end with a connection bar (43), which is further pivotally coupled with a stationary base (48). The connection bar (43) has a flat surface (431) on the top and a slant surface (432) under the ring (35) of the extension rod (33). The connection bar (43) is provided at the other end with an inverted U-shaped stop block (433), which extends to the top of a spring (61). The connection base (42) is furnished on one side with a U-shaped plate (44). The U-shaped plate (44) has a protrusion (441) on two sides, each protrusion (441) extending into the upper end of a spring (45). A guide block (46) is seated below the U-shaped plate (44) and receives a square column (47). The square column (47) is affixed at the inner end to the stationary base (48) of the apparatus and provided at the upper end with two cylindrical columns (471). Cylindrical columns pass through the guide block (46) and extend into the lower ends of two springs (45). A cutter (49) is fixedly arranged below the guide block (46). 
     Referring to FIG. 5, a spring (61) mounting over an upright column (60) is disposed under the middle segment of the handle (13). The spring (61) abuts at the top end against the stop block (433) disposed near the end of the connection bar (43) and is adjacent to a tact switch (63) on one side. A spring (70) is hooked at the upper end to a round hole of the driven plate (28) and connected at the lower end to the base so that the free end of the driven plate is urged upwardly. 
     In operation, the handle (13) is lifted first. As shown in FIGS. 6 and 7, the handle (13) brings the stop block (80) by means of the post (131) to escape from the notch (281) of the driven plate (28). As a result, the front end of the handle (13) urges the free end of the driven plate (28) downwardly and the inner end of the driven plate (28) upwardly. By means of the link (27), the driving plate (21) swings a certain angle degree, together with the driven board (24) and the frictional wheels (26) and (26&#39;). Then users can insert binding straps (9) into the space between the tensioning unit (2) and the frictional board (18) and extend it between the melting unit (4) and the base (17). When the binding straps is seated in position, the micro switch (19) is activated and then depressing the switch (15) can start the motor (1) to drive various units. This arrangement can ensure two frictional wheels (26) and (26&#39;) and the frictional board (18) will not malfunction or be even damaged due to incidental actuation. 
     With the handle (13) released, the driven plate (28) and the tensioning unit (2) under the effect of the spring (70) will restore to their initial states. The frictional wheels (26) and (26&#39;) will stably press the binding straps (9) against the slant frictional board (18). When the switch (15) is depressed, the rotation of two frictional wheels (26) and (26&#39;) will stretch the upper binding straps more and more, which makes the frictional board (18) decline gradually. The frictional board finally reaches a point where the frictional board (18) under the effect of a predetermined tension pushes the lower end of the swivel rod (30) to move. At this moment the upper end of the swivel rod (30) will urge the push rod (31) to move into the adjustment block (32). The frictional wheels also move the pin (341) to drive the stationary block (34) and the extension rod (33) to displace sideways. This will make the ring (35) separate apart from the top flat surface (431) of the connection bar (43). Thus one end of the connection bar (43) rises under the effect of the spring (61), with the other end depressing the melting unit (4). At the same moment, the tact switch (63) is activated to stop the tensioning unit (2) and start the melting unit (4). The upward resilient force of the spring (61) is adjustable through turning the nut (64) on the lower portion of the upright column (60). 
     To control the foregoing tension, turning the knob (321) may change the resilient force of the internal spring, which in turn change the action force of the push rod (31) and achieves the purpose of adjusting spring forces. 
     After the melting unit (4) descends, the friction plate (411) under the melting unit (4) cooperates with another frictional plate (171) at a corresponding position on the base (17) to grip binding bands while a cutter (49) presses against the top surface of the upper strap. The melting unit (41) is pivotally connected to a driving plate (412) that is rotatably attached to a U-shaped block (413). As shown in FIG. 9, the U-shaped block (413) is provided on the lower portion with a plurality of rollers (414). The U-shaped space defined in the upper portion is outside the eccentric wheel (111) of the transmission axle (11) and thus it can be driven to move reciprocally, which makes the melting unit (41) quickly move to-and-fro. Consequently, the binding straps (9) are molten between two frictional plates. After melting is finished, the cutter (49) under the guide block (46) is urged by a resilient force to break the binding straps. Thus the invention can achieve the purpose of binding objects and cutting straps (9). 
     After the binding operation is completed, lifting the handle (13) can bring the binding straps and the binding apparatus to separate from each other. The frictional board (18) will not press against the swivel rod (30) forcefully. Motivating by the resilient forces in the adjustment block (32), the swivel rod (30) returns to its initial position. The extension rod (33) also moves sideways under the effect of the spring (37). Since the ring (35) on the extension rod (33) rests on the slant surface (432) of the connection bar (43) at this moment, it will urge the connection bar (43) to move downwardly gradually until the ring (35) reaches the top flat surface (431) of the connection bar (43). When one end of the connection bar (43) is depressed, the other end will ascend to bring the connection block (42) and the melting base (41) to move upwardly. As a result the melting unit (4) goes away from the base (17) and returns to its initial state. 
     As shown in FIG. 1, the manual melting switch (16) according to the invention has an opening (161) formed on the lower portion thereof, through which opening the strut (36) of the extension rod (33) extends. Therefore, during tensioning the binding straps, users can press down the lower end of the switch (16) to move the extension rod (33) sideways, which makes the ring (35) separate from the slant surface of the connection bar (43). After that, the foregoing tensioning operation is stopped and the melting operation starts. The manual control of the melting operation is achieved. 
     As shown in FIG. 12, the invention has two L-shaped blocks (50) respectively arranged on the front and the back of the main body. The L-shaped block (50) is pivotally connected at the middle position to the body, with the outer end thereof disposed outside the base (17) and the inner end extending upwardly. A tine (51) is formed at the inner end. When the handle (13) is lifted the driven plate (28) presses at its end against the tine (51) to arise the outer end of the L-shaped block (50). Such an arrangement allows placement or detachment of binding straps. When stretching or melting and sealing binding straps, the L-shaped blocks (50) confine the binding straps in its track, avoiding the bands slipping out of the preset route and achieving a guiding effect. 
     To sum up, the invention principally makes use of improved tensioning units and melting units to cooperate with a precisely controlled driving mechanism to complete the binding of objects. The binding apparatus according to the invention has the advantages of elaborate structural arrangement, having less weight, and convenience for hand carrying. It has superior performance than a conventional binding machine and meets the essence of a patent. We hereby file an application for a patent grant.