Patent Publication Number: US-4317392-A

Title: Ratchet wrench

Description:
This invention improves the mechanism for quickly releasing a socket. It is disclosed as applied to the wrench of application Ser. No. 149,462, filed May 13, 1980, incorporated by reference. 
    
    
     In the drawing, 
     FIG. 1 is a top view of a preferred embodiment of the invention showing the wrench with the drive in neutral, 
     FIG. 2 is a cross-sectional view taken on line 2--2 in FIG. 1 but with the cap of the wrench turned to latch the drive in a driving position, and 
     FIG. 3 is a cross-sectional view taken on line 3--3 in FIG. 1. 
    
    
     As described in greater detail in application Ser. No. 149,462, the wrench 10 has a handle 12 with a body 14 at one end provided with an internal cylindrical surface 15 which can be engaged by the outer cylindrical surfaces of clutch shoes 16. In FIGS. 1 and 3, the clutch shoes are out of engagement with the cylindrical surface 15. In this position, locking balls 26 are received in a peripheral recess 34 in pushbutton 25 and socket locking ball 42 is cammed outward by head 24f in the lower end of pin 24c slidable in bore 24d. A spring 24 surrounding the pin 24c engages the underside of the enlarged head 24a at the upper end of the pin and urges it upward. The force from spring 24 is transmitted to pushbutton 25 through spring 25a having its lower end seated in socket 25b in head 24a and its upper end seated in socket 25c in the lower end of the pushbutton. The springs 24 and 25a act in opposition on the pin 24c, the spring 25a pushes downward and the spring 24 pushes upward. 
     In FIG. 3, the button 25 is in a lower position than in FIG. 2, and the pin 24c is moved correspondingly lower, but there remains some outward force exerted by the head 24f on the ball 42, a force which is not large enough to prevent mounting a socket on the drive member 41 and which may be sufficient to lock the socket on the drive member. In the FIG. 3 position, there is sufficient clearance in the peripheral recess 34 above the balls 26 to permit pushing the pushbutton 25 still lower to move the head 24f of the pin 24c completely below the ball 42 and to allow the ball to move into the groove 24e in the pin and to be fully retracted within the opening 71. 
     To go from the neutral position of FIG. 3 to the driving position of FIG. 2, the cap 27 is turned in the direction in which the drive is to be established. For driving counterclockwise, the cap would be turned in a counterclockwise direction. The turning of the cap from the neutral position stresses a centering spring (not shown), storing a force which will return the cap to neutral when the drive is subsequently released. When the balls 26 come opposite diametrically opposed grooves 62 in the bore 59 of the cap, the balls move outward into the grooves and the pushbutton 25 moves upward, bringing the relatively shallow groove 35 in the pushbutton opposite the balls. The drive is now latched in the driving position. In the driving position, the clutch shoes 16 are cammed outward into gripping engagement with the surfaces 15 when the body 14 is rotated in the driving direction, and the gripping engagement of the shoes is released when the body is rotated in the reverse direction, thereby producing a unidirectional drive. 
     To change to a new driving direction or to change sockets, the pushbutton 25 is first pushed downward. When the peripheral groove 34 is the pushbutton comes opposite the balls 26, the balls move into the groove and the centering spring returns the cap 27 to the neutral position where the balls 26 are between pairs of grooves 62 and are held in the peripheral groove 34 by engagement with the bore 59 of the cap. To change sockets, the pushbutton 25 is still further depressed, this movement being permitted by the space between the balls 26 and the upper side of the groove 34, thereby moving the locking pin 24c downward until the head 24f is clear of the socket locking ball 42. This allows the socket locking ball to be completely received within the opening 71 and, in the absence of the restraining force of the ball, the socket drops off the drive member 41. When downward pressure on the pushbutton is released, pin 24c moves upward to the position shown in FIG. 3, where the socket locking ball 42 is cammed outward. 
     To reestablish the drive, the cap 27 is turned in the driving direction through an angle of about 45° so that the balls 26 can move outward into the axial grooves 62 in the cap. There are two sets of axial grooves 62 ninety degrees from each other so that the average rotation of the cap from neutral to a driving position is about 45°. 
     In the driving position of FIG. 2, a socket 80 is locked on the drive member 41 by ball 42 which is moved outward by the head 24f at the lower end of pin 24c. The head 24f is moved upward past the center of the ball 42 so that inward movement of the ball 42 is positively blocked and the socket is locked on the drive member. 
     Although the release of the socket is controlled by the same pushbutton 25 that releases the drive to the socket, the drive and socket release are independent of each other. If the wrench is used with a socket which has no recess for the locking ball 42, then the locking ball 42 cannot move outward as shown in FIG. 2, but merely moves into friction gripping engagement with the socket. With this type of socket, the pin 24c would be lower than illustrated, so that the ball could be fully retracted within the opening 71. Under these conditions, the pushbutton 25 and cap 27 control the drive in the same manner as described above. It is not essential that the pin 24c move upward to the position shown in FIG. 2 for the drive to be established. The drive is independent of the socket locking pin. The drive depends on the position of the pushbutton. The spring 25a exerts a sufficient upward pressure on the button 25 to move the button from the FIG. 3 to the FIG. 2 position. 
     The drive can be returned to neutral by pushing the button 25 until the shallow peripheral groove 34 comes opposite the ball 26, as shown in FIG. 3. The FIG. 3 position can be a storage position for the wrench. 
     When the wrench is to be used, the proper size socket 80 is mounted on the drive member 41 and the cap 27 turned in the direction in which the drive is to be established. All this is entirely independent of the position of the pin 24c which controls the locking of the socket on the drive member.