Blind Rivet Fastening Device

Abstract

To provide a blind rivet fastening device that makes it easy to mount a blind rivet in the nose and that keeps the mounted blind rivet from falling out of the nose. When the nose is connected slidably to the tool housing in the axial direction, the nose resists the action of the elastic pushing means and is slid so as to be pulled rearward in the axial direction, and the jaw is pulled rearward in the axial direction in the jaw guide. When this has occurred, the inner diameter of the jaw is increased, the mandrel is easily inserted into the jaw, the force pulling the nose rearward in the axial direction is released, the jaw is returned forward axially in the jaw guide by the pushing force of the elastic pushing means, and the inner peripheral surface of the jaw is frictionally engaged with the mandrel.

1 . A blind rivet fastening device for joining a plurality of workpiece components with a workpiece blind rivet, the blind rivet comprising a mandrel, including a shank and a head, and a main body, including a sleeve and a flange, and the sleeve deforms and spreads when compressed by the movement of the mandrel head, thereby capturing and compressing the fastened plurality of components between a spread deformed sleeve portion and the flange; and the rivet fastening device comprises:
 a tubular hollow nose for receiving the mandrel shank;   a tool housing arranged axially to the rear of the nose;   a jaw guide arranged inside the nose and axially movable within the nose, the jaw guide including a radially tapered inner surface that defines a cavity that expands from a forward smaller first radius to a rearward larger second radius;   a pulling head connected to the jaw guide for moving the jaw guide axially in the nose;   a jaw, including a plurality of jaw segments, defining a mandrel gripping space of a variable diameter, and the jaw is axially and radially movable inside the jaw guide;   a spring acting between the pulling head and the jaw to push the jaw forward within the jaw guide;   a transmission arranged in the tool housing and operable to move the pulling head axially, the transmission being operable by a trigger lever installed in a handle formed integrally with the tool housing; and   characterized in that the nose is axial slidably relative to the tool housing, and:
 when the nose is pulled rearward, then the jaw is moved rearward in the jaw guide and compresses the spring, and the jaw segments move radially outward and increase the diameter of the mandrel gripping space; and 
 when the nose is released, the spring pushes the jaw forward in the jaw guide, and the jaw pushes the nose forward, and the jaw segments move radially inward and decrease the diameter of the mandrel gripping space. 
   
     
     
         2 . The rivet fastening device of  claim 1 , wherein the trigger lever is connected pivotably to the handle by a pin, and the trigger lever includes an operating portion extending lengthwise from the pin in a first direction and a mounted portion extending lengthwise from the pin in a second direction opposite to the first direction, and the operating portion is operable to energize the transmission, and the mounted portion is operable to pull the nose rearward. 
     
     
         3 . The rivet fastening device of  claim 2 , wherein the nose includes a nosepiece and a nose housing integrally connected with the nosepiece and axially slideable with respect to the tool housing, and rivet fastening device further comprises a linkage extending rearward along the tool housing, and a first end of the linkage engages the mounted portion of the trigger lever, and a second end of the linkage is connected to a rear end of the nose housing, and:
 when the mounted portion is depressed, then the link slides rearward and pulls the nose rearward, and the nose pushes the jaw rearward along the jaw guide and against the spring, and   when the mounted portion is released, then the spring pushes the jaw forward, and the jaw pushes the nose forward.   
     
     
         4 . The rivet fastening device of  claim 1 , wherein a back end of the jaw guide is connected integrally with a front end of the pulling head. 
     
     
         5 . The rivet fastening device of  claim 4 , wherein the spring comprises a jaw pusher engaging the back end of the jaw and a jaw pusher spring acting between the jaw pusher and the pulling head. 
     
     
         6 . The rivet fastening device of  claim 1 , wherein the plurality of jaw segments are assembled circumferentially to define the mandrel gripping space. 
     
     
         7 . The rivet fastening device of  claim 2 , wherein the transmission includes a motor and a drive shaft rotated by the motor, and the rivet fastening device further comprises a power switch for supplying power to the motor, and the power switch is located in the handle, and the power switch includes an operating pin acted on by the operating portion of the trigger lever. 
     
     
         8 . The rivet fastening device of  claim 7 , wherein a front end portion of the drive shaft is formed with one of male threading and female threading, and a rear portion of the pulling head is formed with the other of male threading and female threading, and the male threading is engaged with the female threading, and the pulling head can not rotate, whereby rotation of the drive shaft in a first rotary direction causes the pulling head to move forward, and rotation of the drive shaft in a second rotary direction causes the pulling head to move rearward. 
     
     
         9 . The rivet fastening device of  claim 8 , wherein a hollow cavity within the tool housing forms a mandrel collector for housing expended mandrels, and the expended mandrels enter the mandrel collector via an axial bore in the jaw guide and pulling head. 
     
     
         10 . The rivet fastening device of  claim 9 , wherein a cover is installed on the mandrel collector that can be opened to remove the expended mandrels stored therein. 
     
     
         11 . The rivet fastening device of  claim 7 , wherein the motor is installed in the rear of the tool housing, and the pulling head is arranged in the front of the tool housing, and the mandrel collector is arranged in the middle of the tool housing between the motor and the pulling head. 
     
     
         12 . A blind rivet fastening device for joining a plurality of workpiece components with a workpiece blind rivet, the blind rivet comprising a mandrel, including a shank and a head, and a main body, including a sleeve and a flange, and the rivet fastening device comprises:
 a tool housing defining a longitudinal axis and including a handle;   a tubular jaw guide slidably mounted in and axially movable relative to the tool housing between a forward start position and a rearward stop position, the jaw guide including a front end, a rear end, and a tapered interior surface tapering rearwardly from a lesser radius to a greater radius, the tapered interior surface including a jaw engagement surface;   a plurality of jaw segments located coaxially within the jaw guide and defining an axial gripping bore of a variable diameter, the jaw segments engageable with the jaw engagement surface and radially movable thereby between an inward compressed position and an outward expanded position, the jaw segments axially movable within the jaw guide from a forward position to a rearward position, and due to the interaction of the jaw segments and the jaw engagement surface the forward position corresponds to the compressed position and the rearward position corresponds to the expanded position;   a bias mechanism acting on the jaw segments to urge the jaw segments forward into the compressed position;   a tubular nose, including a forward end and a rearward end, mounted on and coaxially with the jaw guide, and axially movable relative to the jaw guide between a forward normal position and a rearward mandrel loading position, and in the rearward mandrel loading position the nose rearward end pushes the jaw segments from the compressed position rearward within the jaw guide to the expanded position; and   wherein, when the nose is in the mandrel loading position, then the blind rivet shank may be inserted through the nose into the gripping bore defined by the jaw segments, which jaw segments will be in the expanded position.   
     
     
         13 . The rivet fastening device of  claim 12 , wherein the nose includes a nose piece and a nose housing, the nose housing coaxially surrounding and axially movable relative to the jaw guide and including a nose housing front end and a nose housing rear end, and the nose piece is connected at the nose housing front end. 
     
     
         14 . The rivet fastening device of  claim 12 , and further comprising a linkage, and an operator, the operator is mounted in the handle and the linkage is connected between the operator and the nose, and the operator is operable for moving the nose, via the linkage, from the normal position to the mandrel loading position. 
     
     
         15 . The rivet fastening device of  claim 12 , wherein the bias mechanism includes a spring acting between the jaw guide and the jaw segments. 
     
     
         16 . The rivet fastening device of  claim 12 , further comprising a transmission located in the housing and operatively connected to the jaw guide and operable for moving the jaw guide between the start position and the stop position. 
     
     
         17 . The rivet fastening device of  claim 16 , wherein the transmission includes a pulling head, a motor, and a drive shaft rotated by the motor, and the pulling head includes a front end connected to the jaw guide, and a front end portion of the drive shaft is formed with one of male threading and female threading, and a coaxial rear portion of the pulling head is formed with the other of male threading and female threading, and the male threading is engaged with the female threading, and the pulling head can not rotate, whereby rotation of the drive shaft in a first rotary direction causes the pulling head to move forward and pushes the jaw guide toward the start position, and rotation of the drive shaft in a second rotary direction causes the pulling head to move rearward and pulls the jaw guide toward the stop position. 
     
     
         18 . The rivet fastening device of  claim 17 , wherein the rivet fastening device further comprises a power switch for supplying power to the motor, and the power switch is located in the handle, and the power switch includes an operating pin acted on by a trigger lever. 
     
     
         19 . The rivet fastening device of  claim 12 , wherein at least the nose, jaw segments and jaw guide define an axial bore that provides a passage for the movement of expended mandrels rearward to a mandrel collector located in the housing.