Abstract: A safety switch includes a processor and a display device. The processor is configured to: set an operation mode of the safety switch; an output unit configured to output a mode notification signal for indicating whether the operation mode of the safety switch is in a maintenance mode; receive an input of a display control signal based upon a system operation mode of a switch system including the safety switch and at least one other safety switch. In response to reception of the input of the display control signal based upon a fact that the system operation mode is in a system maintenance mode indicating that at least one of operation modes of the safety switch and the at least one other safety switch is set to the maintenance mode, the display device displays the indication indicating that the system operation mode is in the system maintenance mode.

Abstract: The control device of a tape feeder, during the loading processing, in a case in which carrier tape that is preadjusted such that a length from a first cavity, which houses the electronic component and which is first from the leading end of the carrier tape among the multiple cavities, to the leading end of the carrier tape is a regulated length is inserted into the insertion section, starts conveyance of the carrier tape and makes a position of the first cavity a specified position in the feeder main body in accordance with a detection result of the detection sensor.

Abstract: A component supply device includes a plurality of kinds of tape feeders capable of mounting a first component storing tape by which supplying of components is performed precedingly, and a second component storing tape by which supplying of components is performed succeedingly; a component sensor configured to detect runout of the components in the first component storing tape; and a control unit configured to control a tape feeding operation. A specified discharge length by which the first component storing tape is discharged at the time of occurrence of the runout of the components is preliminarily set for each kind of the tape feeder. The control unit is configured to make the tape feeder perform a tape feeding operation for feeding the first component storing tape by the specified discharge length when the component sensor detects the runout of the components in the first component storing tape.

Abstract: A nail supply device for pneumatic nail gun, including a piston seat, a longitudinal slideway, a transverse slideway connected to the longitudinal slideway, nail guide plates, and a slide clearance; the lower surface of the piston seat having a nail output interface; the upper surface of the piston seat having a nail inlet hole vertically connected to the nail output interface, the front side of nail inlet hole is connected to the rear side of longitudinal slideway; the front sidewall of the piston seat having a piston hole and a nail push hole adjacent to the piston hole, the nail push hole is connected to the longitudinal slideway. The nail supply device for pneumatic nail gun of the present invention can supply nails automatically when the pneumatic nail gun is nailing, the nailing efficiency and nailing quality are guaranteed effectively.

Abstract: A fastening tool configured to fasten a workpiece via a multi-piece swage type fastener including a pin and a collar includes an anvil, a pin-gripping part, a driving mechanism, an electric motor, a control part and a housing. The driving mechanism is configured to move the pin-gripping part relative to the anvil in a first direction along an axis so as to cause the anvil to press the collar engaged with a shaft part of the pin in a second direction and in a radially inward direction. An operation mode of the driving mechanism can be selectively switched between a plurality of operation modes including a first mode, in which a process of fastening the workpiece is completed based on a state of the fastener, and a second mode, in which the process of fastening the workpiece is completed based on a driving state of the motor.

Abstract: A surgical stapling system can include a reload shaft. The shaft can include an elongate tubular member with have a jaw assembly at the distal end thereof and a coupling collar at the proximal end thereof. The shaft assembly also includes an articulation joint coupling the jaw assembly to the distal end. A drive member and an articulation member extend within the tubular body of the shaft from the proximal end to the distal end. A firing member is connected to the distal end of the drive member such that advancement of the drive beam advances the firing member to close the jaw assemblies and fire staples from a reload positioned in the jaw assembly. The shaft assembly can also include a lockout mechanism to prevent a firing operation on a previously-fired reload or no reload.

Abstract: An apparatus is configured to process a work piece and includes a robotic arm, a sealant discharger, and a plasma discharger. The robotic arm includes a distal end that is rotatable with respect to an axis of the robotic arm. The sealant discharger includes a sealant outlet configured to discharge sealant while the sealant outlet is at a first point. The sealant discharger is mounted on the distal end such that the first point is located on the axis. The plasma discharger includes a plasma outlet configured to discharge plasma while the plasma outlet is at a second point that is located a distance apart from the axis. The plasma discharger is mounted on the distal end such that the second point is rotatable around the axis.

Abstract: The present disclosure relates to a surgical fastener applying apparatus for applying fasteners to body tissue. The apparatus includes a cartridge receiving half-section defining an elongated channel member configured to releasably receive a firing assembly and a single use loading unit. A lockout structure prevents insertion of the single use loading unit into the channel member after the firing assembly is mounted to the cartridge receiving half-section. Alternatively, the lockout structure prevents full insertion of the firing assembly into the cartridge receiving half-section, if the single use loading unit is not engaged with the firing assembly.

Abstract: A refill case (A) is provided with: an accommodating part (2) in which staple-sheets, each of which is formed by connecting straight staple members in a sheet shape, are stacked in an up/down direction and accommodated; a front wall (8a); a leading-out port (3) formed in the front wall (8a), and from which a lowermost staple-sheet of the stacked staple-sheets in the accommodating part is led out forward; and an eaves part (7) formed in an upper side of the leading-out port (3). The eaves part (7) includes a front end (7F) positioned in a front side of the front wall (8a) and a lower surface (7L) formed between the front end (7F) and the front wall (8a).

Abstract: A method, a system and a processing device for simultaneous manual retooling of at least two units or for simultaneous exchange of at least two format parts within a processing device. The processing device includes at least two working areas, each including a retooling area, a working opening and an activation device. The working openings exist in an open retooling state or in a closed processing state. For retooling at least two of the working openings are opened. The actual state of the working openings of at least two working areas is determined. Furthermore the activation of at least one activation device is recognized. If the activation devices of open working openings are activated simultaneously, a repositioning of convertible units or format parts is triggered.

Abstract: A power tool is provided including a housing; a driver configured to move downward during a drive stroke and upward during a return stroke; an electric motor configured to drive the driver; and a control unit. The control unit is configured to control a supply of power form a power source to the motor and brake the motor upon or within a predetermined time after the driver reaches approximately its uppermost upward position to stop the motor prior to the completion of the return stroke.

Abstract: A safety method for a nail gun includes a camera capturing an image in front of the nail gun; checking the image to determine whether there is a person in front of the nail gun and cutting off power from the nail gun if a person is in front of the nail gun.

Abstract: A stitcher system includes a stitcher mechanism for stitching collations of documents and adapted to form stitches from a conductive wire moved into the stitcher mechanism. A non-conductive spool is mounted for rotation on a spindle. A conductive wire is wound on the non-conductive spool. The conductive wire has a tail end adjacent to the non-conductive spool and a lead end remote from the spool. The spool rotates when the conductive wire is moved into the stitcher mechanism to provide conductive wire to be used by the stitcher mechanism to form stitches. A sensing circuit is provided with a circuit path that includes the conductive wire wrapped on the non-conductive spool and a conductive member mounted to engage the wire. The sensing circuit path becomes open when the conductive wire is not wrapped on the non-conductive spool to thereby detect an out of wire condition.

Abstract: The present invention includes various embodiments directed to apparatus and methods surrounding a fastener device. In particular embodiments, the fastener device is a quick charging and discharging device that includes a solenoid, a fastener striker, a flash capacitor, and a control circuit. Other novel features of the fastener device exist. In particular embodiments, the present invention also includes apparatus and methods related to deforming staples for securing conduit and the like, and staple insulation and insulated staples that may be discharged by the fastener device. The insulation may be provided in an ordinary staple strip for use in the fastener device. Each insulation form may include deformation voids to assist the adaptation of the insulation about a target object that is being secured by the insulated staple.

Abstract: A positioning device for a hand-held setting tool (10) having an actuation switch (13) for actuating the setting tool (10), with the positioning device including a rod-shaped holder (21); a connection element (22) for the setting tool (10) arranged at an end of the holder (21), and an actuating switching device including an actuation element (24), a switching link (30) connecting an actuation element (24) to the actuation switch (13), and a safety device (40) for preventing actuation of the actuation switch (13) and having a gravity-controlled intermediate element (41) having an actuation position in which it is positioned between first controlling element (34) and second control element (35) of the switching link (30), and an interruption position (16) in which it interrupts the switching link (30).

Abstract: An ergonomically efficient cordless power tool system having desired power-to-weight ratios may be configured by reducing weight in one or more constituent weight groups of a given cordless power tool system, while maintaining or improving the total power output of the tool system. An example cordless power tool system may be configured to output a maximum power of at least 475 watts, and have a maximum power output to weight ratio of at least 70 watts per pound (W/lb).

Abstract: A stapler apparatus of the type using continuous belt-formed staples 200 includes a staple feed claw 25 for advancing the staples 200 sequentially to a stapling position 103, and a drive means 50 for driving the staples 200 drawn to the stapling position 103. A clincher means 40 bends the ends of the staples 200 driven into the sheets and pivots a staple feed pawl 25 interlocked to the staple bending operation of the clincher means 40 for sequentially feeding the staples 200 to the stapling position 103. This construction lightens the load on the drive means to staple sheet stacks, facilitates smooth driving operation of the drive means, and reduces the occurrences of trouble.

Abstract: Described herein is a bucking tool (10) for retaining a burr washer in place whilst a rivet is reacted. The tool (10) comprises a sleeve (12) with a shaft (14) slidably mounted within it. The sleeve (12) has a recess (22) formed at one end (20) for receiving the washer. The shaft (14) has a handle (16) attached at one end (18), the handle (16) being operable to move the shaft (14) in a longitudinal direction within the sleeve (12).

Abstract: A surgical grasping instrument for grasping an elongated implement, which comprises a frame; an elongated member connected to the frame and extending distally therefrom, the elongated member defining a longitudinal axis; and a pair of jaw members operatively connected to the elongated member, the jaw members being adapted for movement between an open position and a closed position, at least one of the jaw members having a recess defined therein and arranged about a central recess axis extending at an angle of about 35° or less relative to the longitudinal axis of the elongated member, wherein upon movement of the jaw members to the closed position, the jaw members form a holding groove that can engage and firmly secure the elongated implement.

Abstract: The present invention provides a sheet binding apparatus for effecting stapling operation by rotation of a motor including a current measuring device for measuring a current of the motor, a first timing output device for defining the timing of the stapling operation, a second timing output device for effecting the output at a different timing from an output timing of the first timing output device, a calculation device for measuring outputs of the current measuring device in response to signals from the first and second timing output devices to seek the difference between the measured values, a base current measuring device capable of setting a current value in advance on which the judgement of the presence/absence of a needle is based, and a discriminating device for comparing an output value from the calculation device with a set value of the base current value setting device to judge the presence/absence of the needle.

Abstract: A base assembly for use with a riveting apparatus such as an electromagnetic riveter (EMR). In one aspect of the invention, the base assembly includes a base plate (42) having a raised beveled portion (80) extending upwardly from the upper surface (54) of the base plate (42). A mounting plate (72) fits on and is secured to the base plate (42) by a plurality of coil springs (90-93). The mounting plate (72) has a recessed portion (66) in the lower surface thereof which mates with the raised portion (80) of the base plate (42). Trip switches (104-107) are positioned in the mounting plate (72) for detection of movement of the mounting plate (72) relative to the base plate (42) in response to undesired contact between the EMR and a part assembly or fixture therefor. An output signal indication is provided when one or more of the trip switches (104-107) are actuated.

Abstract: A rivet tool is mounted on a bracket which can be moved vertically up and down suitable guides. To counterbalance the system an air cylinder supports the bracket and a precision pressure regulator responds very rapidly to continuously maintain a selected pressure in the cylinder. The tool will accordingly be maintained in a perfectly counterbalanced condition continuously.

Abstract: A strip of acetate of a selected length is cut from a ribbon of acetate by a heated cutting wire after the strip has a middle portion clamped between two pairs of fingers. A first outer portion of the strip is then folded beneath the middle portion of the strip at an angle thereto and adjacent thereto after which a second outer portion of the strip is folded at an angle to both the first outer portion and the middle portion and adjacent the first outer portion. The folded portions of the strip are held in the folded relationship as the fingers are advanced to an attaching apparatus at which the portions of the strip are attached to each other to form a bow and to a garment. Activation of the attaching apparatus is prevented if the operator has an extremity disposed in an area where the extremity will be struck by a portion of the attaching apparatus during activation of the attaching apparatus.

Abstract: In a stapling device for sheet stacks 9 in which at least one stapling head 1 is provided whose drive 11 is actuated by a switching mechanism, the switching mechanism cooperating with a sensor sensing the thickness of the sheet stack to be stapled. The sensor has a movable sensing element in the form of a pressure member 17, 25 which, during sensing movement, presses a broadside of sheet stack 9 against an abutment 27 so that the thickness of sheet stack 9, positioned between the abutment 27 and the pressure member 17, 25, limits the path length of the sensing movement of the pressure member 17, 25.

Abstract: An electric circuit interlock system which senses the position of the plurality of doors associated with a machine enclosure, the enclosure providing a safety guarding. The electric safety interlock system disables a main drive motor system when any one of the plurality of access doors is ajar. A manual override jog button is integrated into the electric safety interlock system at each of the plurality of access doors for jogging the main drive motor system. When any more than one of the plurality of access doors are open, each and every associated manual jog buttons must be actuated simultaneously to jog the main drive motor system (logical AND).

Abstract: A powered fastener installation apparatus and method wherein the successful installation of a fastener is indicated by directly detecting the event of the fastener stem breaking. The device releases any partially upset fastener before withdrawing from the workpiece so as to prevent damage to the workpiece. The fastener installation device includes means for transferring the fastener from a feed module to the pulling head and avoiding partial upsetting or disassembly of the fastener, which can lead to jamming the device. The pulling head and transfer apparatus are provided with a vacuum to retain the fastener without mechanical gripping, thereby allowing easy purging of the fastener and preventing the fastener from falling out of the device unintentionally. Moreover, use of the vacuum retention allows greater flexibility and tolerance of errors in the placement and angular orientation of the robot arm and workpiece.

Abstract: An improved surgical stapling apparatus containing a locking mechanism to prevent reactuation of the apparatus, the locking mechanism comprising a resilient clip having a hook which is engagable with a locking notch on the cam bar retainer. The resilient clip is initially held in a non-engagable position by means of a movable chock. When the stapler is actuated for the first time, the cam bar retainer pushes the chock into a subsequent position where the chock no longer blocks the resilient clip. The resilient clip then moves to a position where the hook is engagable with the locking notch. Once the cam bar retainer is retracted it can no longer be reactuated.

Abstract: A sheet stapler apparatus including a cartridge for containing a belt of connected staple wires, a movement confining device provided in the cartridge for confining movement of the staple wires, and a device for stapling sheet materials with the leading staple wire from the belt. A device feeds the staple wires out of the cartridge to the stapling device, and a detecting device detects when the staple supply in the cartridge is almost empty. A control device, responsive to the detecting device, prohibits feeding of the belt by the feeding device, at which time the movement confining device acts on the staples to keep them in the cartridge.

Abstract: A percussion tool of the repeatedly operating type includes a housing, a striking cylinder received in the housing for movement therealong, and a driving piston received in the striking cylinder for movement therealong. The striking cylinder cooperates with the housing to provide a switch valve means which is responsive to the movement of the striking cylinder along the housing for selectively interrupting fluid communication between the interior of the striking cylinder and a discharge port and communicating the interior of said striking cylinder with a compressed air source when the striking cylinder is at its lower position to thereby move the striking piston to cause an associated striking driver to strike a driven element and for selectively interrupting the communication between the interior of the striking cylinder and the compressed air source and communicating the interior of the striking cylinder with the discharge port as the striking cylinder is moved from its lower to upper position.

Abstract: A powered fastener installation apparatus and method wherein the successful installation of a fastener is indicated by directly detecting the event of the fastener stem breaking. The device releases any partially upset fastener before withdrawing from the workpiece so as to prevent damage to the workpiece. The fastener installation device includes means for transferring the fastener from a feed module to the pulling head and avoiding partial upsetting or disassembly of the fastener, which can lead to jamming the device. The pulling head and transfer apparatus are provided with a vacuum to retain the fastener without mechanical gripping, thereby allowing easy purging of the fastener and preventing the fastener from falling out of the device unintentionally. Moreover, use of the vacuum retention allows greater flexibility and tolerance of errors in the placement and angular orientation of the robot arm and workpiece.

Abstract: Fastener installation apparatus for operating cylically so as to instal successively a plurality of fasteners of the type in which a portion is broken off at installation (e.g. breakstem blind rivets) comprises a fastener installation head (11) and a pipe (31) for conveying the broken-off portions away from the head to a receptacle (15). Detection device (48) is mounted adjacent the pipe (31) to detect the presence of a broken-off fastener portion at a pre-determined position (58) there along near the receptacle (15). When a portion is thus sensed, an electrical signal is sent by the detection device (48), via a relay (51), to the installation control system (14a, 14b), so as to allow cyclical operation of the system to continue.

Abstract: An external electronic measuring apparatus 2 in which a sample book block 1 is clamped and the thickness is then determined as a displacement-dependent actual value. The apparatus further includes a microprocessor 20 in which the actual displacement value is evaluated, and is stored as a required value, and a control unit 19 for transmitting the required value to the actuators 44, 45, as an actuating variable. The measuring apparatus possesses a clamping device 8, 9 which can be driven by a motor, and which enables two or more actual displacement values to be determined, these values being functions of differing compressive forces which serve to hold the book blocks in the bookbinding machine 42. These actual displacement values are defined by switch arrangements 20, 38, 13, and 39, as pressure points P1, P2 . . . Pn, and are determined, as actual displacement values, by means of a displacement measuring facility 31-35, in a sequentially controlled procedure.

Abstract: The invention involves apparatus for equipping circuit boards with electronic components wherein the terminal pins of the components inserted into openings in the circuit board lying on an anvil. The anvil serves the purpose of severing and bending the terminal lugs by means of suitable cutting tools each consisting of a stationary and a movable knife. Monitoring devices are provided for the terminal pin ends protruding from the openings on the side of the circuit board opposite the components. According to the invention, there is assigned to each terminal pin (26, 27) a magnetic field-dependent sensor (151, 251), whose actuating magnet (131-140, 231) is movable over monitored. Preferably the individual push rods (101 to 110) are guided at a lateral distance between the movable knifes (7, 10; 17, 20), under spring pressure.

Abstract: Apparatus which applies staples to groups of sheets at the discharge end of a rotary printing press has a rotary conveyor which transports the groups of sheets past a stapling station where the groups are provided with pairs of staples. If one of the two regular stapling units is out of commission, an auxiliary stapling unit is started in response to detected absence of two staples in each finished product so that the groups of sheets receive pairs of staples while the defective stapling unit is being inspected, repaired or replaced.

Abstract: A method and apparatus for sensing wire movement through a wire stitching machine includes a sensor such as a photodetector or microswitch for sensing movement of wire through the machine and a programmable controller in communication with the sensor for stopping operation of the stitching machine if wire movement is not sensed. The sensor detects the rate of unwinding of wire from a spool that feeds the wire to the stitching machine. The programmable controller includes timers that time frequency and duration of signals from the sensor. If the sensor signals fall below a predetermined frequency or exceed a predetermined duration, the controller responds by stopping the machine and sounding an alarm. The apparatus may also include a second sensor at the diversion gate of the wire stitching machine for sensing the stoppage of wire through the machine in response to the diversion of an oversized article.

Abstract: Apparatus for discriminating signature sets of abnormal total thickness from signature sets having normal total thickness in a saddle-wired preparing apparatus. The discriminating apparatus includes means for electrically detecting the movement of sensor wheels which are adapted to discriminate a signature set of normal thickness from one having abnormal thickness, means for timing the output of this detected signal through a mechanical detector, and solenoid means for switching a stitcher and a deflector lever.

Abstract: A saddle stitching machine wherein the pitch of the chain conveyor which transports successive signatures through the stapling station can be changed by changing the ratio of a transmission which receives torque from the timing shaft of the machine. The conveyor transports the signatures along a straight path and the machine has a reciprocable carriage which is moved back and forth along such path by an adjustable crank drive so that the stroke of the carriage can conform to the selected pitch of the conveyor. The tools which are carried by the carriage are actuated by cams which are movable independently of each other at right angles to the straight path. The cams extend in parallelism with the path of signatures at the stapling station.

Abstract: An electronic component matching system operates in conjunction with a component transport arrangement wherein a component-carrying supply tape from which components are removed for positioning upon a circuit board in a matched manner is linearly displaced. The components are thus sequentially moved to a pick-up point whereupon a predetermined number N of components having similar operating characteristics are incorporated in the same circuit. As the component-carrying supply tape is displaced toward the component pick-up point, an electro-optical sensor detects the presence or absence of components on the supply tape and provides this information to a microcomputer controller.

Abstract: A piston body in a housing has first and second opposite facing pistons and a component lead processing member attached to the body between the pistons and movable with the piston body. A stationary lead processing member in sliding engagement with the movable lead processing member receives the lead to be processed. A lead processing controller includes a light sensor and a light emitting device for sensing the presence of a received lead to be processed and for causing air pressure to be selectively supplied to the pistons for processing the lead.

Abstract: A rivet injector/rejector device (10) is provided for use with a riveting machine (12) having a plurality of rivet gripping fingers (120, 122). The device (10) includes a supporting member (16) fixedly mounted to the riveting machine (12). A tubular member (92) is provided for delivering a rivet (148) to the fingers (120, 122). The tubular member (92) is mounted to the supporting member (16) so that an end portion (118) of the tubular member may be moved downwardly relative to the fingers (120, 122). The end portion (118) is shaped so that as it moves downwardly it spreads the fingers thereby permitting a rivet to drop free therefrom.

Abstract: A press having a generally "C" shaped frame, punch mounting means arranged on an upper part of the frame, and anvil support means provided on a lower part of the frame. A relatively deep throat is thereby afforded for sheet metal which may be inserted between said punch mounting means and said anvil support-means. Anvil-support suspension mounting means are provided on the upper part of the frame to allow a further anvil support to be suspended from that part of the frame, whereby smaller work can be operated on by the machine.

Abstract: A device for mounting an integrated circuit with two rows of terminal pins to a circuit board comprises a pair of stationary knives and a pair of movable knives, each stationary knife overlying the respective movable knife on opposite sides of a stationary anvil member. Each stationary knife is provided in the region of its cutting edge with a multiplicity of spaced parallel slots extending transversely to the cutting edge, whereby the stationary knife is formed in the region of the cutting edge with a multiplicity of cutting tabs. Each cutting tab is connected to a respective strain gauge strip in turn electrically connected to a processing or monitoring circuit by means of a multiplicity of leads. The monitoring circuit detects the electrical resistances of the strain gauge strips and thereby determines whether the corresponding cutting tab has been loaded or engaged by a terminal pin during a bending and severing operation. The monitoring circuit includes a microprocessor and a display.

Abstract: A riveting press wherein a stationary lower tool is in line with a vertically reciprocable upper tool which is moved up and down in response to rotation of a first cam mounted on the output shaft of an electric motor. The output shaft carries a second cam with an endless cam groove for the follower at the upper end of a first elongated bar which is coupled to the upper portion of a second elongated bar with limited freedom of reciprocatory movement. The lower portion of the second bar carries a pair of grippers which can releasably hold a component of an article of hardware to be affixed to a sheet of textile material between the two tools. A coil spring biases the two bars apart so as to increase the distance between the follower and the grippers and to thereby close an electric switch which is in circuit with the motor.

Abstract: A low-wire sensor for sensing when the amount of wire W remaining on a spool 102 falls below a predetermined low level, comprising a lever 11 biased by a spring 15 so as to press against the wire W on the spool exceeds the low level and to disengage from the wire when the wire reaches said low level for movement to a wire-low indicating position in which it suitably actuates a sensor switch.

Abstract: A machine for affixing e.g. snap fasteners, rivets and the like to workpieces has a stationary lower tool and a downwardly movable cooperating upper tool. To protect the finger of an operator against injury by the tools the machine also has a finger guard positioned to move ahead of the descending upper tool. The finger guard is mounted on two parallel upright links which are longitudinally shiftable relative to each other. When the finger guard encounters an obstacle this results in shifting of one link relative to the other and two normally engaged contacts in an electrical circuit for the machine drive move apart, interrupting the circuit and shutting down the machine drive.

Abstract: Dispensing of attachment members, each formed by a filament with a head at one end and a cross bar at the other end, using an ejector with forward and return strokes. Each attachment member is dispensed during the forward stroke of the ejector and an antijam mechanism is operated for assuring completion of the return stroke of the ejector and prevention of premature operation.

Abstract: A hydraulically actuated power cylinder reciprocates a driver to exert a compressive force to upset a rivet with the power cylinder's movement being made to correspond to the movement of a pump cylinder by a fluid connection therebetween. The pump cylinder's movements are mechanically actuated according to a programmed cam and actuation is made to occur only during the riveting cycle by a control circuit operating a clutch and brake with the circuit inhibiting operation upon the sensing of a malfunction.

Abstract: in a finisher for finishing sets of copy sheets by stapling the sets into stapled booklets, staple sensing apparatus for sensing whether or not a staple has been properly driven, through the set of sheets. If a staple has been properly driven the legs of the staple effect an electrical continuity between staple clinchers. The electrical continuity is sensed and a first signal is produced indicative of a proper staple to permit continued operation of the finisher and electrographic apparatus to which it is attached. If an electrical discontinuity is sensed, a second signal is produced indicative of an improper staple and a display is actuated to indicate this condition to the operator.