Abstract:
A powered stapler mechanism with a pivotal head mounted in a housing comprised of an upper portion and a lower portion including a lower floor and upstand structure to which the mechanism is anchored. The pivotal head is raised by cam means during the stapler cycle and the housing portions are lockable together using an axle and a slide lock.

Description:
BACKGROUND OF THE INVENTION 
     Prior housed power staplers have included those shown in U.S. Pat. No. 4,720,033 in which a drive-control unit powers the stapler blade down to staple and then back up again. Other powered staplers are disclosed in U.S. Pat. No. 4,542,844 and an unjamming arrangement is shown in U.S. Pat. No. 4,913,332. 
     Housed staplers for selectively stapling multiple sheets heretofore have failed to achieve full success in stapling stacks employed in heavy duty applications. 
     SUMMARY OF THE INVENTION 
     Broadly, the present invention is a housed stapler which comprises (1) a stationary base plate supported on a lower housing portion (2) a lockable, removable upper housing portion for locking to the lower housing (3) a clinching anvil unit (4) control means for lifting the stapler head above the anvil unit to accommodate for variable stacks of paper from thin to thick stacks (5) a rotatable eccentric to limit raising of the stapler head and (6) pivotal eccentric-pin actuating means for moving the actuator for rotating clinching wings of the clinching anvil unit. 
     It is a feature of the invention that long legged staples are provided seriatim which staples are useful in stapling thin (2 or more sheets) and thick stacks (70 or more sheets) since offset leg bending is accomplished after, rather than during, leg penetration of the stack. 
    
    
     BRIEF DESCRIPTION OF THE INVENTION 
     FIG. 1 is a perspective view of the base portion of the housing supporting the stapler mechanism base frame and axle; 
     FIG. 1a is a sectional view along line 1a--1a of FIG. 1; 
     FIG. 2 is a side elevational perspective view of the base portion and upper housing portions of the stapler housing in its locked position; 
     FIG. 2a is a partial enlarged detail of the rear lock in an unlocked position; 
     FIG. 2b is a sectional view along line 26--26 of FIG. 2; 
     FIG. 2c is a detail of the axle arrangement for locking with the upper housing; 
     FIG. 3 is a plan view of the mechanism frame including its base plate and staple leg clincher; 
     FIG. 3a is an elevational view along line 3a--3a of FIG. 3; 
     FIG. 4 is a side elevational view of the mechanism frame; 
     FIG. 5 is a side elevational view of the stapler mechanism in the down, staple-penetrating position; 
     FIG. 5a is a side elevational view of the stapler mechanism in its up position; 
     FIG. 5b is an end elevational view of the stapler mechanism with arms omitted; 
     FIG. 5c is a perspective view of the stapler mechanism power eccentric arrangement; 
     FIG. 5d is an exploded elevational view of a portion of the stapler mechanism; 
     FIG. 6 is a side elevational view of the stapler head, sheath and cartridge; 
     FIG. 7 is a plan view of the variable head lifter mechanism; and 
     FIG. 8 is a sectional view along line 8--8 of FIG. 7. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Viewing first FIGS. 1-5, the powered stapler 10 includes housing 10a consisting of a lower housing portion 11 and upper housing portion 12. The housing 10a is preferably made of molded plastic but may be of any suitable material. Stapler mechanism base frame 13 (FIGS. 3 and 4) is secured to the structure of the lower housing portion 11 and upper housing 12 is removably secured to lower portion 11 as further described. Lower housing 11 includes floor 11a which normally rests on a desk, table or similar surface. Housing portion 11 also has decorative horizontal ridge 11b. 
     Stapler mechanism base frame 13 includes anchor plate 14 (FIG. 1), anchor prong 14a (FIG. 4) and side pieces 16a, 16b with holes 17a, 17b for receiving mechanism mounting axle 18. Plate 14 rests in upstanding lower housing journal mounts 19a, 19b and upstanding forward support 21 which mounts 19a, 19b and support 21 rise from lower housing floor 11a (FIG. 1a). Axle 18 is held on mounts 19a, 19b by round clinch washers 15 which are located in round mount recesses 20a, 20b. Recesses 20a, 20b are shaped so that once washers 15 are secured to axle 18 and positioned in recesses 20a, 20b washers 15 cannot be moved upwardly by lifting or pulling upwardly axle 18 (FIG. 2b). Anchor plate 14 prong 14a fits into slot 22 of forward upstanding support 21. Hold-down lip 23 arising out of floor 11a prevents plate 14 from moving upwardly once assembled (FIG. 1a). Plate 14 is thus anchored structurally directly to floor 11a for greater stability and rigidity. 
     Upper housing 12 carries lock configurations 24a, 24b on each side of housing 12. During assembly housing 12 is manipulated onto and around the ends of axle 18 and is held by axle 18 against lifting off of upper housing 12 when the housing is translated forward and thereafter held forward by latch 25 (FIGS. 2, 2a and 2b). Axle 18 enters left hand configurations 24a, 24b between throat sides 24r, 24l and is captured in configuration offset lobe 24c when housing 12 is translated forward (FIGS. 2b and 2c). Right hand configuration 24b is similarly constructed to receive the other end of axle 18. 
     Turning to FIG. 2a, latch 25 includes housing recess 25a in lower housing portion 11 which recess 25a includes a catch cam lip 25b on its rear wall 11w. Upper housing portion 12 has angled projection 12c on its rear wall 12d. Adjacent on rear wall 12d is mounted slide 25c with thumb pusher 25d which upon insertion of projection 12c against complementary stationary lip 25b is lowered into recess 25a by pushing on pusher 25d. When both projection 12c and slide 25c occupy recess 25a projection 12b cannot be withdrawn from recess 25a thus providing a lock function. 
     Turning now to FIGS. 3 and 3a, staple leg receiving and bending unit 26 includes horizontal anvil plate 27, angled slots 28a, 28b, leg-guide funnels 29a, 29b and pivotal leg-bending clinch wings 31a, 31b. Wings 31a, 31b are operated by kicker plate 34 of actuator unit 33. FIG. 4 shows frame 13 including side pieces 16a, 16b and mount projection 14a. 
     With respect to FIG. 5, frame 13 carries pivotal clinch wing actuator unit 33 about axle 18. Actuator unit 33 includes kicker plate 34 and upstanding two side pieces 36 with cam section 81a on side piece 36 to engage exterior cam pins 38 carried on cam 35 to cause, as further explained, partial rotation up and down of actuator unit 33 to accomplish in a timely fashion staple leg binding. 
     Drive control unit 40, also pivotal about axis 18, includes two side frame pieces 42 and top piece 45. Top piece 45 includes angled bend-up center piece 45a to permit wider opening (up to 7/16&#34;) of stapler 10 for stacks up to 70 sheets for stapling. Also shown is driving blade 50, driver blade housing 51, housing cavity 52, button head 53 and head slot 54. Housing 51, its blade 50 and related parts comprise a staple drive unit 56 which rides up and down on post 57 which in turn is mounted on staple head 55 which is pivotal about axis 18. Head 55 has two spaced apart sides 55a, 55b (see FIGS. 5 and 5a). Drive control unit 40 is driven up and down by dumbbell-arm eccentric 39 which in turn is rotated by bull gear 73. 
     Referring to FIGS. 7 and 8, cross pin 58 and its semicircular end cams 59a, 59b serve to lift staple drive unit 56 and housing head 55 back upward after stapling has been completed. Cams 59a, 59b ride on cam tracks 61a, 61b to raise the stapler unit 56 and head 55 to accommodate thick stacks of paper. Stapler head 55 with walls 55a, 55b carries projection 61 which limits head 55 upward travel when engaged by eccentric as described (FIGS. 5b and 6). 
     In FIGS. 5b, 5c and 5d there is shown top piece 45 supporting motor 71, spur gear 72, bull gear 73. Dumbbell unit 39 rotates about shaft 74 with discs 66a, 67a forming with cross tube 70 one integral piece. Disc 66a is interlocked through lock piece 73a and recess 66c to bull gear 73. Cam 35 is shown with inner lock piece having lock projection 35c which locks into recess 67c of disc 67a so that the cam 35 and disc 67a rotate together about axle 74. Two arms (one omitted from the drawings for clarity) 77, with eyelet openings 77a surround discs 66a, 67a. As the arms 77 swing through their arc during a cycle of the stapler mechanism, arms 77 engage portion 61 of staple head 55 to limit the body upward movement during the return portion of the cycle. Also shown is cam 35 with inner lock piece 35c which interlocks with disc 67a, to turn with it. Since arms 77 surround discs 66a, 67a, the arms engage head 55 to limit its upward movement. Arms 77 are omitted from FIG. 5b for clarity. 
     In the operation of the stapler mechanism, the first step is to insert cartridge 90 loaded with a strip of staple blanks of sufficient size for forming staples capable of securing together 70 sheets or more. Then, a stack of papers from 2 to 70 or more sheets is introduced into stapler 10 between the anvil plate 27 and the staple head 55. When trip-switch (not shown) in the vicinity of stapler head 55 is moved, the stapling cycle is started. Motor 71 rotates spur gear 72 which rotates bull gear 73 causing dumbbell unit 39 to turn about shaft 74. As unit 39 rotates it causes eccentric plastic discs 66a, 66b to turn causing drive control unit 40 to swing downwardly about axle 18. 
     As drive control unit 40 moves downwardly, top cross piece 45 including angled center vent piece 45a pushes down on, and slides along the top of, button 53 causing stapler head 55, also pivotal about axle 18, to descend down onto the top of the stack of paper sheets to be stapled. 
     As the stapling cycle continues the driver blade 50 drives the lead staple with its formed legs through the paper stack. Once the staple legs have passed through the stack they are guided by funnels 29a, 29b into slots 28a, 28b until the staple crown engages the top sheet of the stack. At this point in the cycle, clinching wings 31a, 31b are driven upwardly to bend the legs to clinch the stack. Clinching wings 31a, 31b are caused to pivot and clinch by pivotal actuation of cam wheel 35 carrying projecting pin 38 which pin 38 engages portion 81a of side piece 36 of actuator unit 33 to rotate unit 33 clockwise as viewed in FIGS. 5 and 5a. Kicker plate 34 of unit 33 drives wing 31a, 31b upwardly to clinch (FIG. 5). Cam wheel 35 includes raised portion 35a which engages switch 84 to deenergize the stapler at the end of its cycle (FIGS. 5 and 5b). 
     Once stapling is complete, drive control unit 40 commences its upward travel with staple head 55 being lifted by driver blade 50 until the eccentric 39 with arms 77 engage head sides 55a and 55b and limit its upward movement. Driver blade 50 continues to be lifted by cross pin 58 which includes cross pin cams 59a, 59b mounted on the ends of pin 58. Cams 59a, 59b ride on cam follower tracks 61a, 61b to raise the button 53 and blade 50 until the button 53 enters the area above top plate 45 and below the angled piece 45a. At this point, the cycle ends as switch 84 is operated to end the cycle and stop the mechanism.