US3194324A - Fastener driving tool - Google Patents

Description

July 13, 1965 A. LANGAS FASTENER DRIVING TOOL 2 Sheets-Sheet 1 Filed March 13, 1963 ale/ 421325.

July 13, 1965 A. LANGAS FASTENER DRIVING T001:

2 Sheets-Sheet 2 Filed March 13, 1963 United States Patent 3,194,324 FASTENER DRIVING TOOL Arthur Langas, Chicago, lll., assignor to Signode Corporation, a corporation of Delaware Filed Mar. 13, 1963, Ser. No. 264,902 5 Claims. (Ql. 173-2) This invention relates to a fastener driving tool and, particularly, to a safety mechanism for preventing accidental operation of the tool.

Fastener driving tools such as those that are pneumatically powered are generally controlled by a trigger operated valve mechanism that regulates the flow of highpressure air to and from the driving member of the tool. These tools are used in a large number of industries such as furniture, luggage, and construction.

Tools of this type are designed to respond very quickly, and thus care must be taken to prevent them from being accidentally operated. These tools are used to drive fasteners such as nails, staples, and pins upon the introduction of high-pressure fluid to a driving member. Thus, for all intents and purposes such a tool is a gun that shoots a fastener instead of a bullet into and through members that are to be fastened together. Such a tool can obviously be a dangerous weapon in the hands of a careless, negligent, or playful operator. Unless the operator exercises extreme caution when handling the tool, it could be misdirected and fire a fastener other than into the work, which may damage something or injure someone standing near the operator.

It is with the above possibility in mind that safety mechanisms have been developed to prevent fastener tools from being fired, unless the tool is placed nearby or in actual contact with one of the members to be fastened. One such safety mechanism consists of a mechanical arrangement that locks the trigger against movement unless a safety pin is placed against the work. This type of mechanism has the obvious disadvantage of increasing the amount of time it takes an operator to drive a given number of fasteners. Another mechanism that has been used to prevent accidental firing is a multiple valve assembly employing two valves in series to control the flow of high-pressure fluid between the power supply and the driving member. Both valves have to be operated before a fastener would be driven. One valve is operated by the trigger and the second valve by the safety mechanism. This arrangement requires a large number of parts and is not fail-safe since if the valve operated by the safety mechanism develops a leak, the tool is no longer safe and can be fired by simply pulling the trigger.

In the two types of safety mechanisms discussed above, the members that must be actuatedto efliect operation of the tool are normally spaced at some distance from the point at which the nail is driven, which increases the possibility of the fastener being fired into space. Furthermore, the mechanical arrangement does not allow the trip for the tool to permit the tool to fire the instant actuating member or safety trip pin to serve as a bottom the safety trip pin engages the surface that is to be nailed or stapled.

In accordance with the present invention, there is provided a safety mechanism that will prevent the tool from being fired unless the exit end of the tool is located immediately adjacent the point at which the fastener is to be driven. The novel safety mechanism may also be used as a bottom trip for the tool. Also, the safety mechanism is fail-safe and requires a minimum number of parts.

The safety mechanism embodying the present invention includes a safety trip pin that is located immediately adjacent the point at which the fastener is driven,

which thus all but eliminates the possibility that a fastener will be driven other than into the member that is to be fastened. The trip pin can also be used to control the movement of the valve regulating the flow of air to the driving piston and thus eliminate the need for the operator to move the trigger each time a fastener is to be driven. This provides for very fast action of the tool without any danger to anyone standing near the tool. The novel con struction of the safety device permits it to be used with any conventional tool that is trigger operated without requiring any modifications of the tool to which it is to be applied.

A tool of the type embodying the present invention is illustrated in the attached drawings. The particular tool disclosed is a pneumatic nailer but as such it is merely exemplary of the family of tools to which the safety mechanism can be attached. Generally speaking, the safety device functions to control the movement of the trigger assembly provided for operating the tool. The trigger assembly is designed so that unless the safety trip pin located in the nose of the tool is moved by the member to be fastened, the trigger is ineffective to move the valve to direct air to the driving piston of the tool. The safety trip pin is located in a groove disposed parallel to and immediately adjacent the guide passageway in the nose of the tool for the driving blade and the fastener and extends beyond the nose of the tool. The upper end of the safety mechanism consists of a flange portion that controls the movement of a safety trigger lever that forms part of the trigger assembly. The trigger assembly will not operate to move the valve controlling the flow of air to the driver until the safety trigger lever is properly positioned by the flange of the safety mechanism.

When the tool is first placed in contact with the member to be fastened, the trip pin is pushed back within the groove in the nose of the tool. This rearward movement of the trip pin moves the flange portion of the safety mechanism against the free end of the safety trigger lever to locate it so that pivotal movement of the trigger assembly moves the safety trigger lever against the valve to fire the tool.

It can be appreciated that the trigger can be held in the on position by the operator and the trip pin serves as the valve positioning mechanism.

The structure by which the above and other advantages of the invention are attained will be described in the following specification, taken in conjunction with the accompanying drawings illustrating a preferred structural embodiment of the invention, in which:

- FIGURE 1 is a cross-sectional View of a fastener driving tool incorporating the safety mechanism;

FIGURE 2 is a bottom view of the tool shown in FIG- URE 1;

FIGURE 3 is an enlarged sectional View of the actuating valve and safety trigger assembly;

FIGURE 4 is a view taken along lines 44 of FIG- URE 3;

FIGURE 5 is a view, partially broken away, taken along lines 55 of FIGURE 2;

FIGURE 6 is an outline view of the tool and a sectional View of the safety mechanism with the trigger pulled and the safety mechanism out of engagement with the members to be fastened;

FIGURE 7 is a view similar to FIGURE 6 in which the tool is in position to be fired but the trigger has not been pulled; and

FIGURE 8 is a view similar to FIGURE 7 except that the trigger has been pulled to position the control valve to fire the tool.

Referring first to FEGURE 1, there is illustrated a mailer housing 1 having a body portion 2 that serves as a handle by which the operator may. grasp andmanipm late the mailer. a storage chamber 3 into which air under pressure from any suitable source is introduced through a hose 4 and hose nipple 6 connected to one end of thelstorage cham her 3. 1 At the, other end of the housing 1' is a cylinder 7 in which a'driving piston 8 is slidably disposed. Se-

The handle portion is'cored to provide cured to the underside of piston 8 is a nail driver 9 that 7 extends through a driver and nail guide 11 wherein it engagesthe end nail 12} of an adhered rowof nails located in a magazine 13 secured to the nail housing 1. The housing 1 and nail magazine 13 are interconnected by suitable fastening means. i a The flow of compressed air between the storage chamber 3 and the interior of cylinder 7 above piston 8 is controlled by a diaphragm valve assembly 14 that seats against the upper edge of the cylinder 7. The dia-l phragm assembly'is clamped betwee'nthe'cap 16 and the main portion of housing .1 and serves to block off the 'flowof compressed air between the annular chamber 17 surrounding cylinder 7 and in communication with storage chamber 3 and the chamber 18 within the cylinder rim-V mediately above piston 8. When the diaphragm assem bly14 is raised, the high-pressure air from chamber 17 enters chamber 18 and moves pistons and driver 9 with a sharp, quick driving action against the nail 12 to drive 7 it into place.

The movement of-the diaphragm assembly 14 is controlled by a pilot'valve 29 located in a boss defined by the housing 1., Asillustrated in FIGURE .3, the pilot valve 20 includesa valve housing 21 that has an inlet 22' in communication with thestorage chamber-3,. an outlet port 23 in communication with passage 24 that leadsto the chamber 15;formed between diaphragm assembly '14 and cap 16, and an exhaust port 26. .The -flow1of fluid between passage 24 and exhaust port 26 is controlled by a sleeve 27 that is slidably disposed within'the'valve hous-;

ing 21 and positioned by'a valve member 28; .The valve member 28 is located within the sleeve27 and when first i moved engages the sleeve 27 to shut. oi? the fiow'of fluid A between the storage chamber 3 and outlet port 23fand upon' further upward movement "biases: sleeve 27 away from valve seat 29 surrounding exhaust port 26. to connect chamber 15 andpassage 24 with exhaust port 26 .to vent chamber. 15. I I i i -The valve member 28 is connected at its lower end to plunger 30 and is normally biased into the position shown in FIGURE 3 by a spring 32 extending between plunger 30 and a wallot the valve housing. Extending from the lower end of plunger 30' is a button 31.

Theposition of valve member 28 is controlled by the, operation ofvthe safetytrigger assembly 36 to be de.-

scribed in detail hereinafter. 'When the tool is to befired,

thevalve member 28 is moved upwardly by the triggerassembly '36 to first-block oh. the flow of air' from the;

storage chamber 3 tochamber 15 and then vent chamber 15 to atmosphere to permit the fluid under pressure" in chamber 17 to raise the diaphragm,;assem-bly 14 off its seat to enter chamber 18 and-acton the upp'ersurface of piston 8 to move it in a driving direction against a nail 12. r

.. The trigger assembly '36 consists of a U-shaped trigger 7 member 37 that is pivotally mountedqaboutpin38 thatpositioned "by" the safety mechanis'mj42lso-that pivotal: movement of the trigger assembly 36.?Wi11 movef the lever 41- :into' contact with thebutton 31 to operate the? valve 29. This latter action willilo'ccur when-ithe lip '48i moves and holds the: free end 'of 'the llever .41 inlaposition; where valve-actuating:moVement of tri g r assembly-36] bringsnthe leven ll into contact" with"v alve button-31;

From theforegoing, it will be observed that numerous V variationsand modifications mayheefiected .Without'de l I extends-through aligned openings infianges 1a, 1b ex- 1 tending outwardly from housing l (see FIGURE 2). Lo-' cated within the sidewalls of the trigger assembly and pivot-ally mounted to the endthereof opposite pin 38 by a pin 39 is a safety trigger leverAl. The lever 41, when positioned .by the safety mechanism described hereinafter,"

- functio'nsrto engage button 31 of valve Ztlfto effect open: ing movement of the diaphragm-14. It is to, be noted that unless the safety trigger lever is positioned by the safety mechanism, as described hereinafter, the trigger. member 37 .will engage the tool housing before it can eifejct movement of valve button 31 (see FIGURE 6).

- tion is illustrated in FIGURE8. r 1

.The. satety'mechanism for preventing trigger lever 41. ,l

When the tool is placedin contactfwith the .work to be 1 fastenedas shown inFIGUREEfijthe .safety mechanism; is positioned so thatoperation of the trigger assembly to the position shown in FIGURES moves the valve 20, to: drive a fastener into the work. 3 With the safetymech'an' nism in the position-shown in FIGURE 6, movement of the trigger. will be ineffective toichange the positioniof the valve '20.

The safety;mechanism driver and nail guidell, The track 44- extends: parallel.

to the nail guide andis'locateddmmedialely adjacent The end :o'f'the-pin 43-is' biased outwardly be- 1 yond theend ,ofthe guideaby a s-p'ring46: disposedin a thereto.

recess 10 formed .in the housing 1; The spring 46 is disposed aroundlan upstanding finger portion 47 of the safety. mechanism 42 .l'lA;-portion1of,.the safetymechanis'm ex-- tends upwardly: alongsidefthe' headportion 'ofjthe. housa ing and isbent over; at its upper; endtoform; an out; 1

wardly extending flange"48 that abuts the pin 49 whenthesafety mechanism is in itsfextended position. In this position, as shown in FIGURES .1 and 6,- theqsafety trigger" lever 41 is free tolpivot about pin 39.-

. When the .nose of; the "tool is placed;

safety mechanism -'t 0 :the position shown? If. it is desired to continuously 0 without having to repeatedly phll; the trigger the safety trip pin can be used as 'abottom,trip actua'tor; That is]v to -=say, thet rigg er can be held in the on fiposit ion and E the movement otthe safetyitrip'pin oi the safety mecha-j. I nism used to control the operation bflv'alvellfl by movingthe safety Ltrigger leverg43about pinf 39.-;

, While thetrigger lever 41 is shownas being res trained" between pin38T-and lip 48,:the invention is not limited to this construction; It is notes sentialthatthe lever 41= I come into contact withjpin 38lduring thezfoperation'of the.

trigger assembly. It isonly necessary that theFlever 41 be partingyfrom' the. true spirit and scope joflthe invention.

For example, the invention is not limited to the particular '7 details of the valve mechanism} andany-valve capable of performingthe functions otthe one. diselosed couldbe Otherchangesfcould be ma de in; the shape andgdesignof some'ofi thecomponents of the k sjtructurahelements illustrated." I'

substituted therefor.

j It is, of. course, intendedto'cover appended claims all such modifications asiall within the scope of the claims. g "'I claim:' i B V 1. In a pneumatic fastening -tool having a handle and ahead portion disposed adjacentthereto in which is lo, cated a fastener driver assembly, means for controllinga-ccidental' operation of'the tool is illustrated in various positions in FIG- J URES 6, 7, and 8. i This, mechanism controls the actuation of the valve 25) by controlling the movement ofthe safety" 42 includes. a safety trip pin 43 2 I 'that is slid'ablydisposed' inla'track 44 formed in the crate the fastener tool the operation of said fastener driver assembly including a valve means, a trigger assembly mounted under said handle and positioned to be manipulated toward said handle to operate said valve means, said trigger assembly including a trigger member pivotally connected to said tool, a lever pivotally mounted at one end to said trigger, a stop disposed adjacent the other end of said lever, a safety mechanism for positioning said lever to condition the trigger assembly to operate said valve upon manipulation thereof, said safety mechanism including a portion adapted to engage said other end of said lever to dispose it adjacent said stop when the tool is brought into contact with a surface into which a fastener is to be driven.

2. A pneumatic fastening tool including a housing defining a handle portion and a head section disposed adjacent said handle containing a fastener driver assembly, means for controlling the operation of said fastener driver assembly including a valve means, a trigger assembly mounted under said handle and positioned to be manipulated toward said handle to operate said valve means, said trigger assembly including a trigger member pivotally connected to said tool, and a trigger lever pivotally mounted to one end of said trigger and adapted to engage said valve, a stop disposed adjacent the other end of said lever, a safety mechanism for positioning said lever adjacent the stop to position the lever to operate said valve upon manipulation thereof, said safety mechanism including a portion adapted to engage said other end of said lever to move it toward said stop when the tool is brought into contact with a surface into which a fastener is to be driven, and means for resiliently biasing said safety mechanism against said surface whereby when the tool is removed from said surface the safety mechanism will disable the trigger lever from operating said valve.

3. In a fastener driving tool having driver means and means for controlling the movement of said driver means including valve means; trigger means for operating said valve means comprising a U-shaped trigger member pivotally connected to said tool, a lever disposed within said trigger member and pivotally connected at one end thereof to said trigger member and adapted to engage said valve means; and a safety mechanism for positioning said lever to condition said trigger means when the tool is placed in contact with a surface into which a fastener is to be driven, said safety mechanism including an abutment portion adapted to engage said lever to pivot it about its connection to the trigger member to condition said trigger means whereby movement thereof will effect movement of the valve to operate said driver means.

4. In a fastener driving too] including a housing containing driver means, said housing defining a longitudinal track adjacent said driver means, and means for controlling the movement of said driver means including valve means; trigger means for operating said valve means comprising a U-shaped trigger member pivotally connected to said tool, a lever disposed within said trigger member and pivotally connected to one end thereof and adapted to engage said valve means; and a safety mechanism for positioning said lever to condition said trigger means, said safety mechanism including a trip member disposed in said track and extending beyond said housing to engage a surface into which a fastener is to be driven and a lip portion adapted to engage the other end of said lever, whereby when the tool is placed against said surface, the trigger means will be effective to poistion the valve to operate said driver means.

5. A fastener driving tool as set forth in claim 4 including resilient means positioned between said housing and said safety mechanism to normally position said safety mechanism out of engagament with said lever whereby the tool cannot be fired until said safety mechanism is positioned by contact with the surface into which a fastener is to be driven.

References Cited by the Examiner UNITED STATES PATENTS 2,858,741 11/58 Simpson 42-7O 3,011,169 12/61 Cast et a1. 144.4 3,056,965 10/62 Rogers 1-44.4-

GRANVILLE Y. CUSTER, 111., Primary Examiner.

Claims (1)

1. IN A PNEUMATIC FASTENING TOOL HAVING A HANDLE AND A HEAD PORTION DISPOSED ADJACENT THERETO IN WHICH IS LOCATED A FASTENER DRIVER ASSEMBLY, MEANS FOR CONTROLLING THE OPERATION OF SAID FASTENER DRIVER ASSEMBLY INCLUDING A VALVE MEANS, A TRIGGER ASSEMBLY MOUNTED UNDER SAID HANDLE AND POSITIONED TO BE MANIPULATED TOWARD SAID HANDLE TO OPERATE SAID VALVE MEANS, SAID TRIGGER ASSEMBLY INCLUDING A TRIGGER MEMBER PIVOTALLY CONNECTED TO SAID TOOL, A LEVER PIVOTALLY MOUNTED AT ONE END TO SAID TRIGGER, A STOP DISPOSED ADJACENT THE OTHER END OF SAID LEVER, A SAFETY MECHANISM FOR POSITIONING SAID LEVER TO CONDITION THE TRIGGER ASSEMBLY TO OPERATE SAID VALVE UPON MANIPULA-

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