US2088350A

US2088350A - Electric power-unit for fastenerapplying devices

Info

Publication number: US2088350A
Application number: US54860A
Authority: US
Inventors: Charles E Shanks; Nathan R Smith
Original assignee: Boston Wire Stitcher Co
Current assignee: Bostitch Inc
Priority date: 1935-12-17
Filing date: 1935-12-17
Publication date: 1937-07-27
Anticipated expiration: 1954-07-27

Description

July 27, 1937. c. E. SHANKS YE! AL 2,088,350

ELECTRIC POWER UNIT FOR FASTENER APPLYING DEVICES Filed Dec. 17, 1935 s Sheets-Sheet 1 July 27, 19370 C. E SHANKS ET AL ELECTRIC POWER UNIT FOR FASTENER APPLYING DEVICES Filed Dec.

3 Sheets-$heet 2 3 Sheets-Sheet 3 Filed Dec.

C. E. SHANKS ET AL ELECTRIC POWER UNIT FOR FASTENER APPLYING DEVICES juiy 27, 1937.

Patented July 27, 1937 PATENT OFFICE ELECTRIC POWER-UNIT FOB FASTENER- APPLYING DEVICES Charles E. Shan s and Nathan 3.. Smith. Los

Angeles, Calif assignors to Boston Wire Stitcher Company, Portland, Maine, a corporation of Mil-inc Application December 17, 1935, Serial No. 54.8 60

12 Claims.

This invention relates to an electric powerunit for operating fastener-applying devices such as stapling implements for attaching papers and other sheets, for securing tags and labels to articles of commerce, and for use generally in fastening or stapling together various objects and articles.

One of the objects of the invention is to provide a power-unit of the type indicated including an arm or lever actuated by an electromagnet to operate a movable element of the fastener-applying implement.

Another object of the invention is to provide an apparatus of the type indicated which is adapted to detachably mount seli-contained and interchangeable fastener-applying implements to be actuated by the power-unit to apply the fasteners.

Another object of the invention is to provide an apparatus of the type indicated in which themotion imparted to the actuator by the magnet is multiplied to operate the staple-applying mechanism through a relatively extended stroke.

Another object of the invention is to provide a compact, light-weight power-unit which is conveniently portable and adapted to be connected to any usual outlet for supplying current for its operation.

Another object of the invention is to provide an apparatus of the type indicated which is of simple structure, positive and efllcient in its operation and adapted for use over long periods of time without repair or replacement of its parts.

Further objects of the invention are set forth in the following specification which describes a preferred form of construction ofthe device, by way of example, as illustrated by the accompanying drawings. In the drawings:

Fig. l is a perspective view of the present improved apparatus showing it mounted in operative position on a table and illustrating the relationship of a conventional stapling implement thereto;

Fig. 2 is a longitudinal sectional view of the apparatus shown in Fig. l with a part of the enclosing housing removed and showing the power-operated arm in its raised or inoperative position;

Fig. 3 is a view similar to Fig. 2 showing the arm operated by the energized magnet to actuate the depressible element or the fastener-applying implement;

Fig. 4 is a transverse sectional view or the device taken on line 4--4 of Fig. 3 and showing -the pivotal mounting of the actuating arm between the stanchions on the supporting base;

rounding its edge.

Fig. 5 is a transverse sectional view taken on line 5-5 of Fig. 3 and showing the manner of attaching the electromagnet and enclosing nousing to the supporting base;

Fig. 6 is a transverse sectional view taken on line H of Fig. 3 and showing the relationship of the elements of the electromagnet and the actuating arm;

Fig. 7 is a transverse sectional view taken on line '|l of Fig. 3 and showing the manner of clamping a self-contained fastener-applying implement in adjusted position on the supporting base of the apparatus; and

Fig. 8 is a diagrammatical view of an electrical circuit for controlling the electromagnet.

The present invention consists in general in providing a power-unit to which a standard type of desk stapler or other self-contained fastenerapplying implement may be applied for operation therefrom. The fastener-applying unit is adapted to automatically feed the fasteners which are driven into engagement with the work by the actuation of a depressible element thereon. The depressible element is actuated by an arm on the power-unit mounted for swinging movement about a fixed pivot and extending longitudinally of the unit. The arm carries an armature adjacent its pivot which is operated through a relatively short stroke by an electromagnet. The opposite end of the arm moves through a considerably longer stroke to actuate the depressible element of the fastener-applying unit. The energization of the magnet is controlled by an electric circuit including a circuit-breaker of the push-bottom type adapted to be operated by an attendant.

In the preferred form of the invention as ilillust-rated in the present drawings the apparatus includes a relatively long and narrow supporting frame or base 9 preferably constructed as an aluminum casting having a horizontal platform l0 and a depending marginahflange II sur- An upstanding marginal rib 82 extends around the edge of the platform l0, terminating on either side at a point spaced from one end. A cross-rib I3 extends between the opposite sides of the marginal rib ii to form a forwardly located recess ll and a rearwardly-positioned recess 15. A plurality of bosses i6 formed on the bottom of the platform Ill carry rubber feet I! to adapt the base to be positioned on a table, desk, bench or the like without marring its finish. On opposite sides of the base 9 adjacent the ends of the marginal rib i! are bosses l8 into which threaded studs 19 are screwed or otherwise secured to project upwardly from the ed to be screwed toward or away from the platform I! of the base member for a purpose as will later be explained. In the rearward recess I5 are pairs of laterally-spaced vertical stanchions 2| and a pair of laterally-spaced longer stanchions 22 for carrying the parts of the power-operated mechanism to be later described. Suitable holes 23 areprovided in the cross-rib l3 through which screws may be passed to permanently attach the base 9 to a table, bench or other support if desired.

The forward portion of the frame or base member 9 is ,adapted to support a fastener-applyingimplement, indicated in the drawings by the reference character 25. As herein illustrated the implement 25 is of a form and construction as illustrated and described in an application for U. S. Letters Patent Serial No. 696,353, filed November 2, 1933, but implements of other types may also be applied to the power-unit. Suilice it to state herein that the fastener-applying implement or stapling device comprises a base 26 having a clinching anvil 24 at its forward end; an arm 21 pivoted to the base and forming a magazine ,for containing a supply of fasteners or staples 28; and a depressible lever 29 on the pivoted arm connected to a driver 30 for applying the fastenerslor staples to the work. To apply the stapling device 25 to the power-unit its base 26 is slid inwardly under the nuts 20 carried by the threaded studs l9, the opposite portions of the marginal rib |2 together with the crossrib |3 acting to guide the base into position on the supporting platform "I. The implement 25 is then clamped in adjusted position by turning down the nuts 28 on the studs I9 which en age the base 26 to clamp it securely to the platform l0 as shown in Fig. 7.

The depressible lever 29 of the fastener-applying implement 25 is operated by an arm 32 actuated by an electromagnet in the power-unit. As herein illustrated the arm 32 is pivotally mounted at one end between the laterally-spaced stanchions 22 on the base H! 'of the unit. As most clearly shown in Fig. 4, the arm 32 has a bore 33 in axial alignment with bores 34 at the upper ends of the stanchions 22. A pivot pin 35 extends through the bores 33 and 34 with nuts 36 screwed onto its threaded ends, a suitable bushing 31 being provided in the bore 33 surrounding the pin. The arm 32 is normally urged to rock about its pivot 35 to raise its forward end by the tension of a hairpin spring 38. The spring 38 is arranged with its crossbar 39 engaging the underside of the arm 32 and its legs 40 extending across the projecting ends of the pin 35 and bent inwardly to engage the forward sides of the stanchions 22. At the opposite free end of the arm 32 is a button 4| of hard rubber or its equivalent which is positioned directly above the knob 42 on the depressible lever 29 of the fastener-applying unit 25. The button 4| is attached to the arm 32 in any suitable manner as by means of a cap-nut 43 screwed onto a suitable threaded fastener extending through the arm 32, see Fig. 2. Intermediate its ends the arm 32 has an encircling rubber buifer ring 44 for limiting its upward movement by engagement with the housing 45 to be later described in detail.

The arm 32 is adapted to be actuated by an electro-magnet 58 carried by the supporting frame 9 and to this end the arm carries an arjoint.

mature 5|. The armature 5| is in the form of a rectangular block of laminated construction with overlying strips of metal rigidly connected by rivets 52. A bore 53 extends through the center of the armature 5| and is countersunk at one end to provide a conical seat 54. A stud 55 extends through the bore 53 in the armature 5| with its conical head 56 engaging the seat-54 and its threaded end screwed through the arm 32 and locked in place by a nut 58. The bore 53 is slightly larger than the shank of the stud 55 to provide a clearance to permit limited rocking movement of the armature 5| longitudinally'of the arm 32.

The electromagnet 50 may be of any suitable form to adapt it to attract the armature 5| and, as herein illustrated, it comprises an E-shaped laminated iron core 60 and coil 6| on the centrally-positioned leg of the core. Preferably, the magnet is of the alternating current type having its coil windings so designed that the current flow at the end of the operating stroke of the arm 32 is only one-tenth of its maximum value whereby arcing at or burning of the switch contacts is avoided. As most clearly shown in Fig. 6, the coil 6| is held in position on the core 68 by means of a U-shaped strap 62 embracing the centrally-positioned leg of the core and with its opposite ends 63 bent outwardly over the top of the coil. The magnet 50 is mounted on the supporting frame or base 9 with the outer legs of the core 60 positioned between the laterallyspaced stanchions 2| of each pair. The core 60 is rigidly attached to the stanchions 2| by means of rivets 64 extending through suitable aligned apertures in the outer legs of the core and stanchions. The upper ends of the outer legs of the core 60 have suitable short-circuiting rings 65 set in slots therein and functioning to give a delayed action to the armature 5| and arm 32.

The electromagnet 50 and rearward portion of the actuating arm 32 are enclosed by the housing 45, previously referred to, which is made in two cooperating parts 69 and I0 suitably shaped to enclose the elements. The edges of the walls of the two parts 69 and 18 of the housing abut in a vertical plane centrally of the base 9 and the part 10 has a projecting bead H to form a lapped The bottom of the housing 45 rests on the platform Ill within the marginal rib l2 and the separable parts 69 and Hi have inwardlydirected feet 12 which are attached to the platform H] by means of screws 13 extending through the platform and screwed into tapped holes in the feet, see Fig. 5. Bosses 14 formed integrally with the parts 69 and 10 of the housing project inwardly from its opposite sides to guide the armature 5| for movement in a vertical plane. The housing 45 has a forwardly-positioned aperture 16 through which the arm 32 projects longitudinally of and above the fastener-applying implement 25.

The coil 6| of the magnet 60 is energized from a suitable source of current flowing through an electric circuit including a connector plug 8| and circuit-breaker or switch 82. As shown diagrammatically in Fig. 8, current enters from one side of the line 80 through one contact of the plug 8| and thence flows through the coil 6| of p the magnet 60, through the circuit-breaker 82 and then back to the opposite side of the line. In the preferred form of wiring herein illustrated the two conductors are carried by a single cable 83 of usual construction having the plug 8| and circuit-breaker 82 at the opposite ends and a looped portion extending into the housing 45 through a suitable opening 84. The looped portion of the cable 83 embraces the stanchion 22 to resist pulling strain applied to the cable. One of the conductors in the looped portion of the cable 83 within the housing is withdrawn and connected in series with the coil 6| while the circuit-breaker 82 is connected across the conductors at the end of the cable. As herein shown the circuit-breaker or switch 82 is enclosed in a compressible actuator of soft rubber adapted to rest on the floor and to be depressed by the foot of an attendant to close the circuit. The invention having now been described as embodied in a preferred form of construction its mode of operation will next be explained.

The frame 01" base 9 is mounted on a table, bench or other support on which it is to be used and may be permanently attached thereto. by screws or the like extending through the holes 23 in the base. The fastener-applying implement 25 is then placed on the base 9 and adjusted so that the knob 42 of the depressible lever 29 is positioned directly below the rubber button 4| at the end of the arm 32. clamped in adjusted position by turning'down the nuts 20 on the threaded studs l9 until they engage the beveled side portions of the base 26 to rigidly clamp it on the platform H]. The

parts of the apparatus are then positioned as shown in Fig. 2 with the spring 38 acting on the arm 32 to raise the latter to engage the rubber ring 44 with the housing 45. The connecter plug 8| is inserted in a suitable electrical outlet to connect the circuit of the apparatus with the source of current as indicated in Fig. 8. The compressible switch actuator 85 carrying the circuit-breaker 82 is placed on the fioor adjacent the table in position to be actuated by the attendant and the apparatus is ready for use.

The attendant places the work to be stapled, indicated by the reference character 11: in Fig. 2, on the base 26 beneath the pivoted arm 21 of the fastener-applying implement 25. The implement '25 is so constructed as to automatically advance the staples 28 or other fasteners to a position beneath the driver 30 which applies them to the work in the usual manner. To operate the stapling device the attendant depresses the actuator 85 to close the circuit at the switch .82. When the circuit is thus closed current from one side of the line fiows through the windings of the magnetic coil 6i, thence through the circuitbreaker 82 and through the plug 8! to the opposite side of the line. The coil 6i will consequent- 1y be energized to set up a strong magnetic field which attracts the armature 55 with considerable force to swing the arm 32 downwardly from the position shown in Fig. 2 to that shown in Fig. 3 against the action of the spring 38. The armature 5! is guided in its movement by the inwardly-projecting bosses 14 on the housing 45 and because of its loose mounting on the arm 32 is permitted a limited longitudinal rocking movement to compensate for the angular relation of the arm with respect to the ends of the core 60 disposed opposite the armature.

During the downward movement of the arm 32 the button 4| at its outer end engages the knob 42 on the depressible element 29 of the stapling device 25 to apply a staple to the work w, the legs of the staple being clinched against the underside of the work by the anvil 24. The armature 5! is located adjacent its pivot 35 on the The implement 25 is arm 32 and consequently ,it moves through a relatively short stroke, thus acting to actuate the arm with a maximum force. The free end of the arm being, located a considerable distance away from the pivot is moved through a relatively long stroke to actuate the fastener-applying implement 25. The arrangement of the magnet 5|! and armature 5| permits a variable stroke of the actuating arm 32 and the forward portion of the arm is reduced in thickness to adapt it to yield to compensate for different thicknesses of the work being operated upon.

After each operation of the implement 25 the operator releases the pressure on the actuator 85 of the circuit-breaker 82 to open the circuit and deenergizes the coil 6| 0! the magnet. The hairpin spring 38'then acts between the .stanchions 22 and the arm 32 to rock the latter on its pivot 35 to raise its forward end. The lever 29 and pivoted arm 21 of the fastener-applying implement 25 will then be raised to the position shown in Fig. 2 during which movement another fastener or staple 28 is automatically fed to a position beneath the staple-driver 30. The attendant continues to operate the device to apply fasteners in the manner as above explained, the operation being performed at a high rate'of speed limited only by the operator's adeptness in feeding the work to and removing it from the machine. It will be understood that two or more of the units may be arranged adjacent each other and operated in unison by a common switch to simultaneously apply a plurality of fasteners to the work; or the frame 9 may be arranged to detachably mount a plurality oijthe fastener-applying implements 25 to be actuated simultaneously by the power-operated unit. The implements 25 may'also be adapted forlateral adjustment on the base of the unit to vary the spacing between the fasteners applied thereby.

The apparatus and its mode of operation having now been described it will be observed that the present invention provides an extremely simple and compact power-unit for operating fastener-applying implements at high speed with a minimum of eifort on the part of the operator toavoid fatigue, while increasing the efficiency of the implement to which it is applied.

While we have herein shown and described one preferred embodiment of the apparatus it is to be understood that various modifications may be made in the structure and arrangement of its parts without departing from the spirit or scope of the invention. For example, the stapling mechanism may be permanently built into the supporting frame of the unit or other forms of self-contained fastener-applying implements may be substituted for that shown. Therefore, without limiting ourselves in this respect, we claim:

1. In an apparatus of the type indicated, the combination of a support, a self-contained fastener-applying implement detachably mounted on the support, said implement having a depressible element for actuating it to apply the fasteners, an arm having one end pivoted to the support with its opposite end adapted to actuate the depressible element of the fastenerapplying implement, and an electromagnet intermediate the ends of the arm for moving the latter about its pivot to operate the fastenerapplying implement.

2. In a self-contained apparatus of the type indicated, the combination of a support, means for detachably mounting interchangeable fastener-applying implements on the support for adjustment in relation thereto, means for clamping the implement in adjusted position on the support, said implement having a depressible element operative to apply the fasteners to the work, an arm having one end pivoted to the support and its opposite end adapted to'actuate the depressible element of the fastener-applying implement when the arm is moved about its pivot, and an electromagnet on the support adjacent the pivoted end of the arm for operating the latter whereby the actuating end of the arm is given a relatively long stroke with respect to that portion of the arm attracted by the magnet.

3. In an apparatus of the type indicated, the combination of a support, a fastener-applying implement on the support, an arm having one end pivoted to the support and its opposite end adapted to actuate the fastener-applying implement, an armature carried by the arm adjacent its pivoted end, and an electromagnet on the support for attracting the armature to rock the arm about its pivot, said armature having a limited rocking movement longitudinally of the arm to provide for its self-adjustment with respect to the magnet.

4. In a fastener-applying device, a support, means movable on the support for driving fasteners, an arm having one end pivoted to the support with its opposite end adapted to actuate the fastener-driving means, and an electromagnet adjacent the pivoted end of the arm for actuating the latter whereby the arm has a greater range of movement at its free end than at the point of application of the magnetic force.

5. In an apparatus of the type indicated, the combination of a support, a fastener-applying implement detachably mounted on the support, an arm pivotally mounted on the support and adapted to actuate the fastener-applying implement, an electromagnet on the support intermediatethe ends of the arm for operating the latter, an electric circuit for energizing the magnet, and a pedally-actuated circuit-breaker for controlling the electric circuit.

6. In an apparatus of the type indicated, the combination of a support having a recess in its base, studs on the base at opposite sides of the recess, a fastener-applying implement mounted in the recess in the base and movable in relation thereto, nuts on the studs for engaging the implement to clamp it in adjusted position on the support, said implement having a depressible element for operating it to apply the fasteners, an arm pivoted to the support for actuating the depressible element of the fastener-applying implement, and a magnet for operating the arm.

7. In an apparatus of the type indicated, the combination of a support, a fastener-applying implement detachably mounted on the support and movable in relation thereto, said fastenerapplying implement having a depressible element for operating it to apply the fasteners, means for clamping the implement in adjusted position on the support, spaced stanchions extending upwardly from the support, an arm having one end pivotally mounted between the stanchions with its opposite end adapted to actuate the fastenerapplying implement, and an electromagnet between the implement and stanchions for moving the arm about its pivot to actuate the depressible element of the fastener-applying implement.

aoaasso 8. In an apparatus the type indicated, the combination of a support, a fastenerapplying implement detachably mounted on the support, said implement having a depressible element for operating it to apply the fasteners, spaced stanchions on the support, an arm pivoted at one end between the stanchions on the support with its opposite end overlying the fastener-applying implement to adapt it to actuate the depressible element thereof, a spring between the stanchions and arm for holding the arm in inoperative po- 'sition, and an electromagnet on the support between the stanchions and fastener-applying implement for operating the arm against the action of the spring to actuate the depressible element.

9. In an apparatus of the type indicated, the combination of a support, means on the support for applying fasteners including a depressible element, an arm pivoted to the support and adapted to actuate the depressible element, a magnet on the support having a core and a magnetic coil surrounding the core, an armature carried by the arm, a housing on the support enclosing the magnet, and means on the housing for guiding the armature for movement in a vertical plane.

10. In an apparatus of the type indicated, a

supporting base, a fastener-applying implement on the supporting base, an arm pivotally mounted on the base and adapted to actuate the fastener-applying implement, an electromagnet on the supporting base intermediate the ends of the arm, an armature for the magnet, and means for attaching the armature to the arm to provide for its angular adjustment with respect to the arm.

11. In an apparatus of the type indicated, the combination of a supporting base, a fastenerapplying implement mounted on the supporting base and movable in relation thereto, means for clamping the implement in adjusted position on the supporting base, an arm pivotally mounted for movement toward and away from the supporting base, an electromagnet for operating the arm, a housing for enclosing the electro-magnet, said housing having an opening through which the arm extends, means on the end of the arm for engaging and actuating the fastener-applying implement, and a resilient collar on the arm within the housing for engaging the walls of the housing to limit the movement of the arm.

12. In an apparatus of the type indicated, the combination of a supporting base, a fastenerapplying implement detachably mounted on said base and movable in relation thereto, said implement having a depressible element for operating it to apply the fasteners, means for clamping the implement in adjusted position on the base, stanchions extending upwardly from the base, an arm pivotally mounted at one end between the stanchions with its opposite end adapted to actuate the depressible element, an electromagnet on the base between the fastener-applying implement and stanchions, an external armature carried by the arm for cooperation with the electromagnet, a spring acting between the arm and stanchions to normally move the arm upwardly, an electric circuit for the magnet, and a pedally-operated circuit-breaker for controlling the circuit to energize the magnet and actuate the arm.

CHARLES E. SHANKS. NATHAN B. SMITH.