US3804315A

US3804315A - Powder actuated tool

Info

Publication number: US3804315A
Application number: US00259103A
Authority: US
Inventors: R Pomeroy
Original assignee: Omark Industries Inc
Current assignee: Omark Industries Inc; Phillips Drill Co Inc
Priority date: 1972-06-02
Filing date: 1972-06-02
Publication date: 1974-04-16
Anticipated expiration: 1991-04-16
Also published as: IT985651B; DE2325066A1; GB1419649A; JPS4956262A; AU5558573A; AU465253B2; CA971301A

Abstract

A powder actuated tool, including a barrel for receiving in one end thereof a driveable fastener, a driving ram slideable within the barrel for driving the driveable fastener, and a chamber for receiving an explosive cartridge in the end opposite the driveable fastener. Said barrel pivotally mounted to a handpiece whereby in a firing position the cartridge is nested within a breech block provided in the handpiece, and being pivotable away from said breech block for loading and unloading cartridges. Said barrel including a sleeve having a finger adapted to engage and dislodge a cartridge from its chamber, and further including a dog adapted to engage the driving ram for moving the driving ram rearwardly within the barrel. Said dog for moving the driving ram and said finger for retracting the cartridge being cooperative whereby the return of the driving ram creates air pressure behind the cartridge at a point prior to full retraction of the driving ram, and at said point having the finger engaging (and thus dislodging) the cartridge whereby the continued retraction exerts a propelling force to propel the cartridge out of the barrel end.

Description

United States Patent [1 1 Pomeroy 1 1 POWDER ACTUATED TOOL Raymond Visher Pomeroy, Portland, Oreg.

[75] Inventor:

[73] Assignee: Omark Industries, Inc., Portland,

Ohio

[22] Filed: June 2, 1972 [21] Appl. No.: 259,103

Primary ExaminerGranvi1le Y. Custer, Jr.

[57] ABSTRACT A powder actuated tool, including a barrel for receiving in one end thereof a driveable fastener, a driving ram slideable within the barrel for driving the driveable fastener, and a chamber for receiving an explosive cartridge in the end opposite the driveable fastener. Said barrel pivotally mounted to a handpiece whereby in a firing position the cartridge is nested within a breech block provided in the handpiece, and being pivotable away from said breech block for loading and unloading cartridges. Said barrel including a sleeve having a finger adapted to engage and dislodge a cartridge from its chamber, and further including a dog adapted to engage the driving ram for moving the driving ram rearwardly within the barrel. Said dog for moving the driving ram and said finger for retracting the cartridge being cooperative whereby the return of the driving ram creates air pressure behind the cartridge at a point prior to full retraction of the driving ram, and at said point having the finger engaging (and thus dislodging) the cartridge whereby the continued retraction exerts a propelling force to propel the cartridge out of the barrel end.

5 Claims, 5 Drawing Figures PATENTEBAPR I 61974 SHEET 1 OF 2 wivq w s Ms w. a M NW %N 3 o F 1 ml. :1 0 w o o [MW NW. I [I d e 0 A l l g Q IN. a r k M...,..,..M.\ Wk 4. mm. Nu Sq w\w@ w mm wms New wk wx m N nU PATENTED APR 1 6 I914 3.804.315

SHEEI 2 OF 2 N N R POWDER ACTUATEI) TOOL HISTORY This invention relates to a powder actuated tool wherein a driving ram is propelled by an explosive force to drive a fastener into hard materials, e.g., concrete and the like.

Powder actuated tools such as contemplated by the present invention are designed for use in the construction industry for driving metal pins or studs into hard surfaces such as concrete. The explosive force required for such driving is generally contained in a cartridge that is inserted in a tight fitting chamber at the rear end of the barrel of the tool. When the tool is fired, the cartridge casing is expanded and becomes jammed in the chamber. The difficulty commonly experienced in attempting to manually remove the cartridge is detrimental to the efficient and safe use of the tool. Thus an object of the present invention is to provide an improved cartridge ejection mechanism.

Very briefly, the present invention is believed most applicable to the type of tool described and illustrated in the U.S. Pat. No. 3,494, I25 issued to D. L. Robinson on Feb. l0, I970. The improvement is primarily in the provision of a sleeve member that carries a finger for dislodging the cartridge and a return dog for returning the driving ram. The finger and dog are so located with respect to each other and the relative positions of the cartridge that the driving ram initially compresses air behind the cartridge prior to full retraction of the ram so that as the finger engages the cartridge and by the following completed retraction of the driving ram. the

. FIG. I showing the barrel ofthe tool pivoted away from the handpiece; 1

FIG. 4 illustrates the spent cartridge being ejected from the tool; and

FIG. 5 is a partial view of the tool of FIG. I illustrating the means for disassembling a part of the tool.

Referring to FIGS. I thru 3 of the drawings, the tool illustrated is comprised of two main portions which are referred to as the barrel assembly I0 and the handpiece I2. The handpiece includes the conventional components. A firing pin 14 is slideably mounted in the breech block I6 but urged to the forward position relative to the breech block 16 as shown in FIG. I by spring 18. The sear 20 carried by the firing pin is urged downwardly as viewed in FIG. 1 by spring 22. When the breech block 16 moves forward relative to the firing pin [4 as shown in FIG. 2 (as when the tool is removed from the work surface). the sear 20 is urged by spring 22 past the shoulder 24 to lock the firing pin in this rear position. Re-engaging the work surface forces the breech block 16 and firing pin 14 rearwardly into position to be refired. Atrigger 26 carries a trigger bar 28 which is adapted to engage the sear 20 and force it off shoulder 24. Springs 30 and 32 urge return of the trigger 26 and trigger bar 28.

THE BARREL ASSEMBLY A mounting ring 34 has an ear portion 36 that is pivotally connected by pin 38 to a barrel support section 40 of handpiece 12. A barrel 42 is held in the mounting ring by set screw 44 which engages the slot 46 to permit limited movement of the barrel 42 relative to the mounting ring 34. A barrel extension 48 is fixed in the end of the barrel 42 by screw threads 50 and set screw 52 inserted through a slot 54 in the end of the barrel extension. A guard 55 is fastened to the mounting ring 34 by a ring fastener 56. A driving ram 58 has a front portion 58 of reduced diameter adapted to slide through the opening of the barrel extension 48, a rear portion 58" and an intermediate tappered portion 58". The tappered portion 58" is adapted to mate with the entrance 60 of the opening in thebarrel extension 48. A head portion 62 of the driving ram, with sealing ring 64, effectively seals against passage of air therepast. The end of the barrel 42 (oppositethe barrel extension) is provided with a cartridge receiving chamber 66, adapted to receive a cartridge 68.

As shown in FIG. I, with the barrel assembly 10 pivoted to its operable position, and with the barrel moved rearwardly in mounting ring 34, the cartridge 68 is abutted against the breech block 16 and in line with the firing pin 14. A sleeve 70 is mounted around the barrel 42 and includes a grip 72 to facilitate manual movement of the sleeve. A ring 74 on the sleeve is provided with a stop in the form of a set screw 76 projected into a slot 78 in the barrel 42. This set screw is adapted to engage a finger 80 which is free sliding in a slot 82 in the barrel 42. An upper boss 83 in the finger 80 is engaged by the stop 76 and forced rearward a limited distance relative to barrel 42. A st0p'8l on the barrel 42 maintains the finger 80 in proper alignment and also prevents the finger from sliding off the barrel 42. A downward flange 84 fits under the cartridge rim and dislodges the cartridge when said stop 76 abuts the boss 83 of finger 80. The ring 74 has a lug 86 to which a dog 88 is pivotally fastened by pin 90. A set screw 92 limits the pivotal movement of the dog 88. The dog 88 passes through a slot 9.4 in the barrel 42 and is located to engage a flange 96 of the driving ram 58.

OPERATION The operation of loading and unloading power load cartridges is illustrated by the sequence of drawings 1 thru 4.

FIG. 1 illustrates the tool just after the cartridge 68 has been ignited by firing pin 14 whereby the driving ram 58 has driven a fastener 98 through a plate 100 and into a concrete support 102. It will be noted that the rear end of the barrel 42 is securely nested in the breech block 16 and the firing pin 14 is fully extended into the breech block 16.

FIG. 2 illustrates the tool removed from its abutting engagement with the plate 100 with the barrel 42 moved forward (manually or gravitationally) in mounting ring 34. The rear end of the barrel is thus free of the breech block 16 and can be pivoted away from the handpiece 12. In a conventional manner, the breech block 16 is biased forward and the finger 14 is limited in its forward movement to reposition the firing pin rearward of shoulder 24.

FIG. 3 illustrates the removal of the cartridge 68. With the barrel assembly pivoted away from the handpiece 12, the sleeve is pulled along the barrel. The dog 88 first engages the flange 96 of the driving ram 58 which is thereby moved rearwardly relative to the barrel by manual pressure on grip 72. As the head 62 of the driving ram passes the end of the slot 94, it begins building pressure behind the spent cartridge 68. The cartridge being expanded is wedged in the chamber 66 and thus rather than being forced from the seating completes the seal and allows for pressure build up until the tip of set screw 76 engages finger 80 with downward flange 84 mechanically dislodging the cartridge. At this point a sufficient pressure is built up behind the cartridge which is momentarily perpetuated by the continued movement of the driving ram toward full retraction to blow the cartridge clear of the tool as shown in FIG. 4. The sleeve is then returned and a hook 104 on the sleeve catches the finger 80 and returns it to its initial position and a new cartridge is placed in the chamber. The barrel assembly is then pivoted back against the handpiece. Inadvertent pivoting of the barrel is prevented by a magnet 106 which acts to hold the barrel assembly in its closed position.

Several features are provided which make assembly and disassembly of the tool more convenient. Such disassembly is important for replacing and/or cleaning the driving ram 58. Thus the barrel extension 48 is screwed onto the end of the barrel 42 and locked against inadvertent removal by set screw 52 which is seated in a slot in the end of barrel extension 48. Furthermore, set screw 52 cannot inadvertently be loosened because to do so would prevent the sleeve from being fully positioned onto the barrel. The rearward end of the sleeve would project past the barrel and prevent the barrel assembly from being pivoted back into its operating position. Note also that the vibration from the tool being operated will not cause loosening ofthe set screw 52 in that it is overlapped by ring 74. The set screw 52 when seated in the slot in the end of the barrel extension also aligns the dog 88 in its slot 94 which extends into the end of the barrel extension.

It will be understood that the barrel extension 48 can be removed by first pivoting the barrel assembly 10 away from the handpiece l2, sliding the sleeve off the barrel. to expose the set screw 52, loosening the set screw and simply unscrewing the barrel extension from the barrel. The sleeve is moved to position the set screw 92 relative to opening 107 to permit insertion ofa tool. The set screw is unscrewed to permit the dog 88 to drop out of the barrel opening and the driving ram is then pushed through the front end of the barrel by a push rod 108 as illustrated in FIG. 5.

It will be understood that the above example is intended to illustrate a preferred embodiment of the invention, the full scope of which is established by the claims appended hereto.

What is claimed is:

l. A tool for explosively driving fasteners into hard surfaces comprising: a handpiece having a handle, a barrel supporting portion extending from the handle, a firing pin carried by the handle, and activating means for activating movement ofthe firing pin along a predetermined path, a barrel assembly pivotally connected to the barrel supporting portion, said barrel assembly including a barrel having one end pivotable between positions into and out of the path of the firing pin, a rim type cartridge receiving chamber in said one end of the barrel and a dislodging finger carried by the barrel forming a part of said cartridge receiving chamber and being movable from a cartridge receiving position to a reject position which movement mechanically dislodges a cartridge in the chamber, a driving ram slideably carried within the barrel between a forward position and a retracted position adjacent the cartridge receiving chamber, a head portion on said driving ram having a substantially air tight fitting with a section of the barrel adjacent the cartridge receiving chamber, and the improvement which comprises a slideable member slideable on the barrel, a first means carried by the slideable member to move the driving ram rearwardly to its retracted position in the barrel, and a second means cooperative with the first means to engage the dislodging finger and thereby mechanically dislodge a cartridge in the cartridge receiving chamber during retraction of the driving ram.

2. A tool for explosively driving fasteners into hard surfaces comprising: a handpiece having a handle, a barrel supporting portion extending from the handle, a firing pin carried by the handle, and activating means for activating movement of the firing pin along a predetermined path, a barrel assembly pivotally connected to the barrel supporting portion of the handpiece, said barrel assembly including a barrel having one end pivotable between positions into and out of the path of the firing pin, a rim type cartridge receiving chamber in said one end of the barrel, a driving ram slideably carried within the barrel and being moveable between a forward position in the barrel and a retracted position adjacent the cartridge receiving chamber, a head portion on said driving ram having a substantially air tight fitting with the section of the barrel adjacent the cartridge receiving chamber, and the improvement which comprises a finger-like member provided on the said one end of the barrel having limited movement relative to the barrel, said finger-like member having a flange forming a part of the entrance of the cartridge receiving chamber and positioned under the rim of a rim type cartridge seated within said chamber, a sleeve slideable on said barrel, said sleeve having a dog projected through a slot in the barrel and adapted to engage the driving ram, said sleeve further having a stop for engaging the finger-like member, said stop, finger-like member, driving ram and dog being positioned relatively whereby movement of the sleeve rearward on the barrel first causes engagement of the dog on the driving ram to create an effective pressure against the cartridge prior to the stop engaging the finger-like member and said stop engaging the finger-like member to dislodge the cartridge at a postion where the driving ram is spaced forward of its retracted position whereby continued retraction of the driving ram propels the dis lodged cartridge out of the barrel.

3. A tool for explosively driving fasteners into hard surfaces as defined in claim 2 wherein the finger-like member slides in a groove in the barrel and including a hook provided at the end of the sleeve to engage and return the finger-like member upon return of the sleeve on the barrel.

4. A tool for explosively driving fasteners into hard surfaces as defined in claim 2 wherein said dog is pivotally connected to a lug of the sleeve, a set screw maintaining the lug projected through the slot and into engagement with the driving ram, said set screw being mounted in said mounting ring, a barrel extension threadably connected to the barrel, and a set screw normally positioned under the sleeve for fixing the position of the barrel extension on the barrel, said set screw projecting into a slot in the barrel extension to orient the barrel extension relative to the barrel.

Claims

1. A tool for explosively driving fasteners into hard surfaces comprising: a handpiece having a handle, a barrel supporting portion extending from the handle, a firing pin carried by the handle, and activating means for activating movement of the firing pin along a predetermined path, a barrel assembly pivotally connected to the barrel supporting portion, said barrel assembly including a barrel having one end pivotable between positions into and out of the path of the firing pin, a rim type cartridge receiving chamber in said one end of the barrel and a dislodging finger carried by the barrel forming a part of said cartridge receiving chamber and being movable from a carTridge receiving position to a reject position which movement mechanically dislodges a cartridge in the chamber, a driving ram slideably carried within the barrel between a forward position and a retracted position adjacent the cartridge receiving chamber, a head portion on said driving ram having a substantially air tight fitting with a section of the barrel adjacent the cartridge receiving chamber, and the improvement which comprises a slideable member slideable on the barrel, a first means carried by the slideable member to move the driving ram rearwardly to its retracted position in the barrel, and a second means cooperative with the first means to engage the dislodging finger and thereby mechanically dislodge a cartridge in the cartridge receiving chamber during retraction of the driving ram.

2. A tool for explosively driving fasteners into hard surfaces comprising: a handpiece having a handle, a barrel supporting portion extending from the handle, a firing pin carried by the handle, and activating means for activating movement of the firing pin along a predetermined path, a barrel assembly pivotally connected to the barrel supporting portion of the handpiece, said barrel assembly including a barrel having one end pivotable between positions into and out of the path of the firing pin, a rim type cartridge receiving chamber in said one end of the barrel, a driving ram slideably carried within the barrel and being moveable between a forward position in the barrel and a retracted position adjacent the cartridge receiving chamber, a head portion on said driving ram having a substantially air tight fitting with the section of the barrel adjacent the cartridge receiving chamber, and the improvement which comprises a finger-like member provided on the said one end of the barrel having limited movement relative to the barrel, said finger-like member having a flange forming a part of the entrance of the cartridge receiving chamber and positioned under the rim of a rim type cartridge seated within said chamber, a sleeve slideable on said barrel, said sleeve having a dog projected through a slot in the barrel and adapted to engage the driving ram, said sleeve further having a stop for engaging the finger-like member, said stop, finger-like member, driving ram and dog being positioned relatively whereby movement of the sleeve rearward on the barrel first causes engagement of the dog on the driving ram to create an effective pressure against the cartridge prior to the stop engaging the finger-like member and said stop engaging the finger-like member to dislodge the cartridge at a postion where the driving ram is spaced forward of its retracted position whereby continued retraction of the driving ram propels the dislodged cartridge out of the barrel.

4. A tool for explosively driving fasteners into hard surfaces as defined in claim 2 wherein said dog is pivotally connected to a lug of the sleeve, a set screw maintaining the lug projected through the slot and into engagement with the driving ram, said set screw being removeable to permit pivoting of the dog out of engagement with the driving ram to allow the driving ram to be ejected out of the barrel.

5. A tool for explosively driving fasteners into hard surfaces as defined in claim 3 wherein the barrel assembly includes a mounting ring pivotally mounted to the barrel supporting portion, said barrel being slideably mounted in said mounting ring, a barrel extension threadably connected to the barrel, and a set screw normally positioned under the sleeve for fixing the position of the barrel extension on the barrel, said set screw projecting into a slot in the barrel extension to orient the barrel extension relative to the barrel.