Punch having changeable punching member

A punch includes a socket disposed on a plate, a barrel supported above the plate, a shaft slidably received in the barrel and a mold piece detachably secured to the shaft. One or more levers have one end pivotally secured to the barrel and have a middle portion coupled to the shaft for moving the shaft and the mold piece downward to actuate on the socket. The mold piece is detachably secured to the shaft with a threaded ferrule. The punch includes one or more mold pieces and sockets of various shapes which may be replaced with each other.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to a punch, and more particularly to a punch
 having one or more punching members that may be replaced with each other.
 2. Description of the Prior Art
 Typical punches comprise a punch rod slidably received in a housing, a knob
 secured on top of the punch rod for forcing the punch rod downward to cut
 or to punch the sheet members. A spring is engaged with the punch rod for
 biasing the punch rod away from the sheet members before the punch rod is
 depressed against the sheet members. The punch rod has a predetermined
 shape which may be used to punch or to form a predetermine-shaped pattern
 on the sheet members. The patterns may not be changed.
 The present invention has arisen to mitigate and/or obviate the
 afore-described disadvantages of the conventional punches.
 SUMMARY OF THE INVENTION
 The primary objective of the present invention is to provide a punch
 including one or more punching members that may be replaced and changed
 with each other according to the user's need.
 In accordance with one aspect of the invention, there is provided a punch
 comprising a plate, a socket supported on the plate and including a recess
 formed therein, a barrel supported above the plate, a shaft slidably
 received in the barrel and including a bottom end extended downward and
 outward of the barrel, a mold piece, means for detachably securing the
 mold piece to the bottom end of the shaft, means for moving the shaft and
 the mold piece downward to actuate on the socket.
 The moving means includes at least one lever having a first end pivotally
 secured to the barrel at a pivot axle and having a middle portion, and a
 pin engaged through the middle portions of the lever and engaged through
 the shaft for coupling the lever to the shaft. The barrel includes at
 least one oblong hole formed therein for slidably receiving the pin and
 for guiding the pin to be moved up and down relative to the barrel. The
 shaft includes at least two holes formed therein for selectively receiving
 the pin. A spring means is further provided for biasing the shaft and the
 mold piece away from the socket.
 The detachably securing means includes a ferrule rotatably secured to the
 shaft, and means for attaching the mold piece to the ferrule. The
 attaching means includes an inner thread formed in the ferrule, and an
 outer thread formed on the mold piece and threaded with the inner thread
 of the ferrule to secure the mold piece to the ferrule. A device is
 further provided for preventing the mold piece from rotating relative to
 the shaft and includes a stud extended from the shaft, and a cavity formed
 in the mold piece for receiving the stud of the shaft, the cavity of the
 mold piece and the stud of the shaft include a corresponding non-circular
 cross section for preventing the mold piece from rotating relative to the
 shaft.
 A device is further provided for preventing the socket from rotating
 relative to the plate and includes one or more projections extended inward
 of an opening of the plate, and one or more notches formed in the socket
 for receiving the projections and for preventing the socket from rotating
 relative to the plate.
 The socket includes a recess formed therein, the mold piece includes a mold
 element extended therefrom for engaging into the recess of the socket. A
 pad is further engaged into the recess of the socket.
 Further objectives and advantages of the present invention will become
 apparent from a careful reading of a detailed description provided
 hereinbelow, with appropriate reference to accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 Referring to the drawings, and initially to FIGS. 1-3, a punch in
 accordance with the present invention comprises an arm 10 secured on a
 plate 11 which includes an opening 12 formed therein and one or more
 projections 13 extended inward of the opening 12 of the plate 11. It is
 preferable that the arm 10 includes a bent portion formed in the middle
 portion thereof. A barrel 14 is secured to the upper end of the arm 10 for
 receiving a shaft 15 and a spring 16 therein and includes a peripheral
 shoulder 18 formed therein for engaging with the spring 16 and for
 retaining the spring 16 in the barrel 14. The shaft 15 includes a head 17
 provided on top thereof and engaged with the spring 16 such that the
 spring 16 may bias the shaft 15 upward relative to the barrel 14 or may
 bias the shaft 15 upward away from the plate 11. The shaft 15 includes a
 stud 19 extended downward and outward of the barrel 14 and having a
 non-circular cross section, such as the square cross section or the like.
 The shaft 15 includes an annular groove 20 formed in the lower portion
 thereof for receiving a clamping ring 21 which may rotatably secure a
 ferrule 22 to the shaft 15. The ferrule 22 includes an inner thread 23
 formed therein. The barrel 14 includes one or a pair of oblong holes 24
 (FIG. 2) formed therein for slidably receiving a pin 37 which is engaged
 through either of the holes 26 of the shaft 15 (FIG. 5), such that the pin
 37 moves up and down in concert with the shaft 15, and such that the
 sliding movement of the pin 37 is limited by the oblong holes 24 of the
 barrel 14.
 A pair of levers 30 each includes one end 31 pivotally secured to a hub 27
 of the barrel 14 at a pivot axle 32 that is formed by one or more
 fasteners 32. The levers 30 each includes one or more oblong holes 33
 formed therein and located close to the one end 31 thereof for receiving
 the end portions of the pin 37 such that the lever 30 may move the shaft
 15 downward against the spring 16 by rotating the lever 30 about the pivot
 axle 32. The lever 30 includes a handle 34 formed on the other end
 opposite to the pivot axle 32 such that the lever 30 may be rotated about
 the pivot axle 32 against the spring 16 by actuating the handle 34. The
 distance between the handle 34 and the pin 37 is preferably greater than
 the distance between the pin 37 and the pivot axle 32, such that the
 moving distance or the moving stroke of the pin 37 is limited, and such
 that the handle 34 may apply a great torque to the shaft 15 via the pin
 37.
 It is to be noted that the pin 37 may be engaged through either of the
 holes 26 of the shaft 15 (FIGS. 5, 6) such that the pin 37 may be adjusted
 up and down relative to the shaft 15 in order to adjust the moving stroke
 or the sliding movement of the shaft 15 relative to the barrel 14.
 Although one pair of the levers 30 are shown in the drawings,
 alternatively, the barrel 14 and the shaft 15 may each include an oblong
 hole formed therein and aligned with each other for receiving a single
 lever 30 which is good enough to move the shaft 15 up and down relative to
 the barrel 14.
 A mold piece 40 includes a protrusion 41 extended upward therefrom and
 having an outer thread 42 formed thereon for threading to the inner thread
 23 of the ferrule 22 and for securing the mold piece 40 to the shaft 15,
 such that the mold piece 40 may be moved in concert with the shaft 15 and
 such that the mold piece 40 may also be moved downward toward the plate 11
 by the lever 30. The mold piece 40 includes a cavity 43 formed therein for
 receiving the stud 19 of the shaft 15 and having a non-circular cross
 section corresponding to that of the stud 19 of the shaft 15 for
 preventing the mold piece 40 from rotating relative to the shaft 15.
 Alternatively, the stud 19 of the shaft 15 and the cavity 43 of the mold
 piece 40 may include a circular cross section and may be keyed together
 for preventing the mold piece 40 from rotating relative to the shaft 15.
 The mold piece 40 includes a mold element 44 (FIG. 3) extended downward
 therefrom and having a shape corresponding to the pattern or the letter or
 the word to be punched and formed.
 A socket 60 is received in the opening 12 of the plate 11 and includes a
 peripheral flange 61 extended radially outward from the upper portion
 thereof for engaging with the plate 11 and for supporting the socket 60 in
 the plate 11. Alternatively, the plate 11 may include a peripheral flange
 extended radially inward of the opening 12 thereof for engaging with the
 socket 60 and for supporting the socket 60 in the plate 11. The socket 60
 includes one or more notches 62 formed therein for receiving the
 projections 13 of the plate 11 and for preventing the socket 60 from
 rotating relative to the plate 11. The opening 12 of the plate 11 and the
 socket 60, as shown in the drawings, include a circular cross section.
 Similarly, the opening 12 of the plate 11 and the socket 60 may include a
 corresponding non-circular cross section for engaging with each other and
 for preventing the socket 60 from rotating relative to the plate 11. The
 socket 60 includes a pattern recess 63 formed therein and having a shape
 corresponding to that of the pattern or the letter or the word to be
 punched and formed and having a shape corresponding to that of the mold
 piece 44 for receiving the mold piece 44 (FIG. 5) and for punching and
 forming the pattern on the sheet members that are engaged between the mold
 piece 40 and the socket 60 or the plate 11, when the mold piece 44 is
 moved downward against the socket 60. The cut materials from the sheet
 members may be received in the pattern recess 63 of the socket 60 and may
 be removed from the socket 60 when the socket 60 is removed from the plate
 11 and is disposed up-side-down, for example. The pattern recess 63 may be
 formed through the socket 60 for allowing the cut materials to be moved
 outward of the socket 60.
 As shown in FIG. 4, a pad 64 has a shape corresponding to that of the
 pattern or the letter or the word to be punched and formed and has a shape
 corresponding to that of the mold piece 44 and that of the pattern recess
 63 of the socket 60 for engaging into the pattern recess 63 of the socket
 60. The pad 64 is made of resilient or soft materials, such as the rubber,
 and may be deformed or compressed when the mold piece 44 is moved downward
 against the socket 60 and engaged into the pattern recess 63 of the socket
 60. After the punching operation, the resilient pad 64 may be recovered or
 expanded back to the original shape for moving the cut materials outward
 of the socket 60 and for allowing the cut materials to be easily removed
 from the socket 60.
 In operation, as shown in FIGS. 3 and 5, the shaft 15 and thus the mold
 piece 40 may be moved downward toward and to engage with the socket 60 by
 depressing the handle 34 of the lever 30 against the spring 16. The lever
 30 may apply a great force to the mold piece 40 such that the mold piece
 40 may be actuate to cut the sheet members of a greater thickness. The
 punch may include a number of mold pieces 40 having mold elements 44 of
 various shapes and a number of sockets 60 having the recess 63 of various
 shapes. The mold pieces 40 and the sockets 60 may be easily changed and
 replaced with each other.
 Accordingly, the punch in accordance with the present invention includes
 one or more punching members that may be replaced and changed with each
 other according to the user's need.
 Although this invention has been described with a certain degree of
 particularity, it is to be understood that the present disclosure has been
 made by way of example only and that numerous changes in the detailed
 construction and the combination and arrangement of parts may be resorted
 to without departing from the spirit and scope of the invention as
 hereinafter claimed.