Compressed air-operated drive-in apparatus

Claim 2

A compressed air-operated drive-in apparatus to drive-in fasteners such as nails, staples or the like, comprising a housing, a working cylinder having an axis in said housing, a driving piston mounted in said working cylinder for reciprocation along said axis, means to receive compressed air in said housing, said housing having atmosphere passage means leading to the atmosphere, main control valve means hAving means to control the application of said compressed air to the piston to move it in the working cylinder, and to allow said piston to move air in the cylinder to said atmosphere passage means, manually actuable release valve means to control actuation of said main control valve means, servo control valve means, said servo control valve means comprising two oppositely effective biasing chambers, one of them being a release valve chamber, said release valve means having means to connect said release valve chamber with the compressed air in the housing when said release valve is actuated, and to connect said release valve chamber to said atmosphere passage means when the release valve is not actuated, said other chamber being a repetition chamber, a control passage, said main control valve means comprising means to communicate said control passage with said compressed air receiving means when the main control valve means is open and to communicate said control passage with the atmosphere passage means when the main control valve means is closed, means to connect said repetition chamber in communication with said control passage, both the main control valve means and the servo control valve means being arranged for movement along the axis of said piston and said cylinder.

Claim 3

The combination of claim 1, a housing cover for said cylinder and piston, said main control valve means being disposed within said housing cover.

Claim 4

The combination of claim 1, said means to receive compressed air in said housing comprising a compressed air supply chamber surrounding said cylinder, said main control valve means having means arranged coaxially with said cylinder, to block the inside of the cylinder from said supply chamber when said release valve is unactuated and said apparatus is in a condition of rest, said housing having an annular portion, said blocking means comprising annular means pressing against said annular portion to cause said blocking.

Claim 5

The combination of claim 3, said main control valve means having a greater effective area on one side exposed to compressed air from said supply chamber when said annular means is pressed against said annular portion, than the effective area of its other side exposed to the inside of the cylinder, said means on said release valve to connect said release valve chamber with the compressed air in the housing and to the atmosphere passage means comprising means to relieve the air pressure from said one side upon actuating said release valve means to cause said annular means to lift from said annular portion to permit entry of compressed air from said supply chamber into said cylinder to cause said piston to move in a working direction in said working cylinder.

Claim 6

The combination of claim 4, said annular means and said working cylinder being fixed to each other and movable together in the housing and constituting a unit, said housing comprising an integrally formed cylindrical guide for said unit, means to permit said unit to be moved as a unit in a hermetically tight manner inside of said housing, said annular means when said apparatus is in a position of rest, being pressed against an end face of said cylindrical guide which end face forms said annular portion, said cylinder being formed with air inlet openings in its upper region, which are exposed for entry of compressed air from said supply chamber into said cylinder, when the unit slides in one direction axially into open position due to said one side of said annular means being relieved from pressure, and to shut off said air inlet openings when said unit slides in an opposite direction upon subjecting said one side of said annular means to compressed air and communicating the space in the working cylinder and above said piston to said atmosphere passage means.

Claim 7

The combination of claim 5, said annular means comprising an annular flange to press said annular portion, said annular flange being part of said working cylinder and having a sealing ring at its underside contaCting said annular portion, and a central circular plate member axially mounted in the upper end of said working cylinder, said member being provided with a cylindrical extension on its upper surface having a central passage extending therethrough for venting the inside of said working cylinder to the atmosphere on its return stroke.

Claim 8

The combination of claim 6, and means providing delaying chamber interposed in said means to communicate.

Claim 9

The combination of claim 7, and an adjustable shut-off device interposed in said means to communicate to connect said control passage alternately with said main valve means and with said repetition chamber, said shut-off device having means to throttle or shut off said control passage.

Claim 10

The combination of claim 8, said control passage being connected with said atmosphere passage means, and means to connect the inside of said working cylinder to said atmosphere passage means.

Claim 11

The combination of claim 9, and trigger means to actuate said release valve means.

Claim 12

The combination of claim 10, and work engaging means to render the trigger means effective to actuate said release valve means when said work engaging means is actuated.

Claim 13

A compressed air-operated apparatus to drive fasteners such as nails or staples, comprising a housing having a cylindrical guide formed with an annular edge, a working cylinder having an axis and slidable in said guide, a drive piston slidable in said working cylinder along said axis, said working cylinder having an annular flange to close on said annular edge, said housing having a compressed air chamber surrounding said cylindrical guide, said working cylinder having openings which open to said chamber upon said cylinder sliding in a direction to lift said flange off said annular edge, a central plate, means to fix said plate to the upper end of said working cylinder, said plate having a central passage, said housing having a passage which opens to the atmosphere and which connects to said central passage when said flange contacts said annular edge, said central plate having means to shut off said atmosphere passage from said central passage when said flange is raised off said annular edge, and servo control valve means mounted in said housing and disposed coaxially of said working cylinder for movement along said axis, manually actuable release valve means, and means controlled by said plate, said servo control valve means and said release valve means, to apply compressed air from said chamber alternately to the upper side of said plate to cause said flange to press down on said annular edge, and to open said side of said plate to said atmosphere passage to allow said working cylinder and flange to lift off said annular edge.

Claim 14

A compressed air-operated apparatus to drive fasteners such as nails or staples, comprising a housing having a cylindrical guide formed with an annular edge, a working cylinder having an axis and slidable in said guide, a drive piston slidable in said working cylinder along said axis, said working cylinder having an annular flange to close on said annular edge, said housing having a compressed air chamber surrounding said cylindrical guide, said working cylinder having openings which open to said chamber upon said cylinder sliding in a direction to lift said flange off said annular edge, a central plate, means to fix said plate to the upper end of said working cylinder, said plate having a central passage, said housing having a passage which opens to the atmosphere and which connects to said central passage when said flange contacts said annular edge, said central plate having means to shut off said atmosphere passage from said central passage when said flange is raised off said annular edge, and servo control valve means mounted in said housing and disposed coaxially of said working cylinder for movement along said axis, manually actuable release valve means, and means controlled by said plate, said servo control valve means and said release valve means, to apply compressed air from said chamber alternately to the upper side of said plate to cause said flange to press down on said annular edge, and to open said side of said plate to said atmosphere passage to allow said working cylinder and flange to lift off said annular edge.

Claim 15

The combination of claim 12, said servo control valve means including a sliding valve member, and means to apply compressed air from said chamber to opposite ends of said sliding valve member.

Claim 16

The combination of claim 13, and a member adjustably mounted on said housing and having means cooperating with said servo control means to cause movement of said piston only once for each actuation of said release valve means when said adjustable member is in one position, and to cause repetitive reciprocations of said piston upon each actuation of said release valve means when said adjustable member is in another position thereof.

Claim 17

The combination of claim 14, said adjustably mounted member being coaxial with said servo control valve means and with said working cylinder.

Claim 18

A compressed air-operated drive-in apparatus to drive-in fasteners, comprising a housing having cylindrical bore means to slidably receive a cylinder, a cylinder having an axis and slidingly received in said bore means, said cylinder having a sealing flange overlying the upper end of said bore means, a piston in said cylinder movable along said axis, means to receive a compressed air in said housing above said piston, said flange, when the cylinder is raised, openIng said cylinder above said piston, to said compressed air receive means, a main valve plate in the upper end of said cylinder, means to cause said main valve plate to lift said cylinder when said main valve plate is raised, said main valve plate having a central through passage, means on the housing to guide said main valve plate for sliding vertical movement up and down, said housing being formed with a chamber disposed above said main valve plate and cylinder, and with a passage communicating the central passage of said main valve plate with the atmosphere when said main valve plate is in lowered position and said cylinder flange is in lowered position sealing the upper end of said cylindrical bore means, a seal fixed in said housing to seal the upper end of said through opening in said main valve plate when said main valve plate is raised, said main valve plate having means to close said passage which communicates the through passage of the main valve plate with the atmosphere when said main valve plate is raised, said housing being formed with an auxiliary valve chamber coaxial with said cylinder, a servo valve vertically slidably mounted along said axis in said auxiliary valve chamber, said auxiliary valve chamber having a first, upper, portion of relatively larger diameter, a second portion of relatively smaller diameter, coaxial with said first upper portion and disposed therebelow, and a third portion disposed below said second portion and of larger diameter than the second portion, and coaxial therewith, said servo valve having a first piston portion sealingly slidable in said first auxiliary chamber portion, a pair of upper and lower spaced piston portions carrying upper and lower sealing rings, respectively, and slidable in said second portion of said auxiliary valve chamber when said servo valve is on an ''''up'''' position, said servo valve having a reduced stem between said pair of spaced piston portions, said auxiliary valve chamber having a fourth portion below said third portion thereof, and of the same diameter as said second portion thereof, said servo valve having a sealing ring below the lower of said pair of sealing rings, and located in said third portion of said auxiliary valve chamber in unsealing condition when said servo valve is in its ''''up'''' position and adapted to have sealing engagement with said fourth portion of said auxiliary valve chamber when said servo valve is in a lowered position, in which position, the lower of said pair of upper and lower sealing rings is in said third portion of said auxiliary valve chamber and out of sealing engagement with respect to said second portion of said auxiliary valve chamber, said housing having means to constantly communicate the compressed air receiving means with said fourth portion of said auxiliary valve chamber, said housing having a passage which connects said third portion of said auxiliary valve chamber to the housing chamber above said main valve and flange of said cylinder, manually controlled valve means to establish communication between said first portion of said auxiliary valve chamber alternately to said compressed air receiving means and to the atmosphere, said housing being formed with a passage leading from said second portion of said auxiliary valve chamber, between said pair of pistons, to the atmosphere.

Claim 19

A compressed air-operated drive-in apparatus to drive-in fasteners, comprising a housing having cylindrical bore means to slidably receive a cylinder, a cylinder having an axis and slidingly received in said bore means, said cylinder having a sealing flange overlying the upper end of said bore means, a piston in said cylinder movable along said axis, means to receive a compressed air in said housing above said piston, said flange, when the cylinder is raised, openIng said cylinder above said piston, to said compressed air receive means, a main valve plate in the upper end of said cylinder, means to cause said main valve plate to lift said cylinder when said main valve plate is raised, said main valve plate having a central through passage, means on the housing to guide said main valve plate for sliding vertical movement up and down, said housing being formed with a chamber disposed above said main valve plate and cylinder, and with a passage communicating the central passage of said main valve plate with the atmosphere when said main valve plate is in lowered position and said cylinder flange is in lowered position sealing the upper end of said cylindrical bore means, a seal fixed in said housing to seal the upper end of said through opening in said main valve plate when said main valve plate is raised, said main valve plate having means to close said passage which communicates the through passage of the main valve plate with the atmosphere when said main valve plate is raised, said housing being formed with an auxiliary valve chamber coaxial with said cylinder, a servo valve vertically slidably mounted along said axis in said auxiliary valve chamber, said auxiliary valve chamber having a first, upper, portion of relatively larger diameter, a second portion of relatively smaller diameter, coaxial with said first upper portion and disposed therebelow, and a third portion disposed below said second portion and of larger diameter than the second portion, and coaxial therewith, said servo valve having a first piston portion sealingly slidable in said first auxiliary chamber portion, a pair of upper and lower spaced piston portions carrying upper and lower sealing rings, respectively, and slidable in said second portion of said auxiliary valve chamber when said servo valve is on an ''''up'''' position, said servo valve having a reduced stem between said pair of spaced piston portions, said auxiliary valve chamber having a fourth portion below said third portion thereof, and of the same diameter as said second portion thereof, said servo valve having a sealing ring below the lower of said pair of sealing rings, and located in said third portion of said auxiliary valve chamber in unsealing condition when said servo valve is in its ''''up'''' position and adapted to have sealing engagement with said fourth portion of said auxiliary valve chamber when said servo valve is in a lowered position, in which position, the lower of said pair of upper and lower sealing rings is in said third portion of said auxiliary valve chamber and out of sealing engagement with respect to said second portion of said auxiliary valve chamber, said housing having means to constantly communicate the compressed air receiving means with said fourth portion of said auxiliary valve chamber, said housing having a passage which connects said third portion of said auxiliary valve chamber to the housing chamber above said main valve and flange of said cylinder, manually controlled valve means to establish communication between said first portion of said auxiliary valve chamber alternately to said compressed air receiving means and to the atmosphere, said housing being formed with a passage leading from said second portion of said auxiliary valve chamber, between said pair of pistons, to the atmosphere.

Claim 20

The combination of claim 16, said housing being formed with a chamber above said fixed seal, said fixed seal having a center hole communicating with said last mentioned chamber, said housing being formed with a passage leading to said last mentioned chamber, a ring, means to mount said ring on said housing for movement up and down on said housing, said ring being formed with an internal annular chamber, said housing having a passage connecting said last mentioned passage with said annular chamber and also being formed with another passage connecting the first portion of said auxiliary valve chamber with said internal annular chamber.

Claim 21

The combination of claim 17, said means to movably mount said ring on said housing comprising a threaded connection between said ring and said housing, said internal chamber being located to adjustably overlap said passage which connects said internal chamber with the passage that leads to said last mentioned chamber.

Claim 22

The combination of claim 16, said cylinder, main valve and auxiliary valve being coaxial.

Claim 23

A compressed air-operated drive-in apparatus to drive-in fasteners, comprising a housing having a cylindrical wall, a cylinder having an axis and slidable in said cylindrical wall, said cylindrical wall having an upper edge, said housing having a pressure chamber surrounding said cylinder, said cylinder having a hole establishing communication between said pressure chamber and the interior of said cylinder, a piston slidable in said cylinder and below said opening, said housing having a passage leading from said pressure chamber to said edge, said cylinder having a flange adapted to be seated on said edge to close said passage when said cylinder is down, a valve plate in the upper end of said cylinder and above said piston, said valve plate having an upwardly extending central sleeve formed with a central through opening, said housing having a bore slidably receiving said sleeve and a relief passage extending to the atmosphere and leading to the upper end of said sleeve when said plate is in a lowered position and said relief passage being adapted to be closed when said plate is raised, means to cause said plate to raise said cylinder when said plate is raised to uncover the passage closed by said flange, a centrally apertured seal fixed in said valve housing and spaced above said sleeve, coaxially thereof, and adapted to be contacted by said sleeve when said plate is raised, said housing being formed with a chamber above said seal, said valve housing being formed with a servo-valve chamber spaced above said last mentioned chamber, said servo-valve chamber having a first upper end portion, a second portion therebelow, a third portion below said second portion and a fourth lower end portion below said third portion, a servo-valve in said servo-valve chamber, said servo-valve having a first piston portion sealingly slidable in said first portion of said servo valve chamber, a second piston portion sealingly slidable in the second portion of said servo valve chamber and a third piston portion sealingly slidable in the second and fourth portions of said servo valve chamber, said housing having a passage connecting a space at the upper end of said cylinder with the third portion of said servo valve chamber, said third portion of said servo valve chamber being of a diameter greater than the diameters of said second and third piston portions of said servo valve, a ring on said housing and having an internal annular chamber, said housing being formed with a passage extending up from the chamber above said seal, and with a passage connecting said last passage with said internal annular passage, and also being formed with a passage connecting the second portion of said servo valve chamber with the atmosphere, said housing being formed with a passage extending to the upper end of the first portion of said servo valve chamber, and with a passage connecting the lower end of said first portion of said servo valve chamber with said last mentioned passage, said housing having a compressed air chamber continuously communicating with said upper edge of said cylindrical wall, said valve housing having a passage leading to said fourth portion of said servo valve chamber, and manually actuable trigger means to continuously open communication between said compressed air chamber and said last mentioned passage and to open the passage which goes to the upper end of the first portion of said servo valve chamber alternately to said compression chamber and to atmosphere.

Claim 24

A compressed air-operated drive-in apparatus to drive-in fasteners, comprising a housing having a cylindrical wall, a cylinder having an axis and slidable in said cylindrical wall, said cylindrical wall having an upper edge, said housing having a pressure chamber surrounding said cylinder, said cylinder having a hole establishing communication between said pressure chamber and the interior of said cylinder, a piston slidable in said cylinder and below said opening, said housing having a passage leading from said pressure chamber to said edge, said cylinder having a flange adapted to be seated on said edge to close said passage when said cylinder is down, a valve plate in the upper end of said cylinder and above said piston, said valve plate having an upwardly extending central sleeve formed with a central through opening, said housing having a bore slidably receiving said sleeve and a relief passage extending to the atmosphere and leading to the upper end of said sleeve when said plate is in a lowered position and said relief passage being adapted to be closed when said plate is raised, means to cause said plate to raise said cylinder when said plate is raised to uncover the passage closed by said flange, a centrally apertured seal fixed in said valve housing and spaced above said sleeve, coaxially thereof, and adapted to be contacted by said sleeve when said plate is raised, said housing being formed with a chamber above said seal, said valve housing being formed with a servo-valve chamber spaced above said last mentioned chamber, said servo-valve chamber having a first upper end portion, a second portion therebelow, a third portion below said second portion and a fourth lower end portion below said third portion, a servo-valve in said servo-valve chamber, said servo-valve having a first piston portion sealingly slidable in said first portion of said servo valve chamber, a second piston portion sealingly slidable in the second portion of said servo valve chamber and a third piston portion sealingly slidable in the second and fourth portions of said servo valve chamber, said housing having a passage connecting a space at the upper end of said cylinder with the third portion of said servo valve chamber, said third portion of said servo valve chamber being of a diameter greater than the diameters of said second and third piston portions of said servo valve, a ring on said housing and having an internal annular chamber, said housing being formed with a passage extending up from the chamber above said seal, and with a passage connecting said last passage with said internal annular passage, and also being formed with a passage connecting the second portion of said servo valve chamber with the atmosphere, said housing being formed with a passage extending to the upper end of the first portion of said servo valve chamber, and with a passage connecting the lower end of said first portion of said servo valve chamber with said last mentioned passage, said housing having a compressed air chamber continuously communicating with said upper edge of said cylindrical wall, said valve housing having a passage leading to said fourth portion of said servo valve chamber, and manually actuable trigger means to continuously open communication between said compressed air chamber and said last mentioned passage and to open the passage which goes to the upper end of the first portion of said servo valve chamber alternately to said compression chamber and to atmosphere.

Claim 25

The combination of claim 20, said servo-valve chamber and said servo-valve being coaxial with said cylinder.

Claim 26

The combination of claim 20, said ring including means mounting said ring for axial movement on said housing and having means to block the passage which connects to said internal annular chamber.