Self-clearing Nose Section For A Powered Fastener-driving Tool

Abstract

A powered fastener-driving tool is provided wherein the nose section thereof may be readily assembled and disassembled, when required, without the need for special tools. The nose section incorporates a self-clearing feature and includes a fixedly mounted inner plate, an outer plate removably mounted in face-to-face relation on the inner plate, a guard piece overlying the outer plate and being slidable relative thereto, and means overlying the guard piece and resiliently maintaining the outer plate in face-to-face relation with the inner plate.

Description

BACKGROUND OF THE INVENTION

In utilizing powered fastener-driving tools, there is a common problem which is encountered; namely, fasteners frequently become jammed in the nose section of the tool. This problem occurs in many instances because the fastener is slightly distorted and, thus, does not assume a proper position prior to being engaged by the driver rod. Also, dirt or other foreign matter sometimes becomes impacted within the nose section obstructing feeding or discharging of the fastener. Whenever any of these conditions occur, it is imperative that at least portions of the nose section be disassembled. Heretofore, the necessary disassembly of the nose section to rectify such a problem was normally a frustrating, time-consuming, and awkward manipulation requiring special tools and considerable dexterity on the part of the person disassembling the tool.

Prior attempts have been made to overcome these problems by modifying the structure of the nose section; however, such modified structures have been beset with one or more of the following shortcomings: (a) the structure was of a complex and costly construction; (b) the structure could not withstand abusive handling and was prone to malfunction; and (c) the structure was hazardous because of the tendency of certain components fragmenting when a jamming condition occurred.

SUMMARY OF THE INVENTION

Thus, it is an object of the invention to provide a powered fastener-driving tool having a nose section which is not beset with the aforenoted shortcomings.

It is a further object of the invention to provide a nose section that is capable of being embodied in powered fastener-driving tools which vary in size and shape and utilize either pneumatic, hydraulic, mechanical or electrical means as a source of power.

It is a still further object of the invention to provide a nose section which is of simple, compact, light-weight and inexpensive construction.

It is a still further object of the invention to provide a nose section which permits certain components thereof to yield slightly when subjected to pressures of predetermined magnitude, thereby providing effective self-cleaning capabilities which reduce markedly the incidents of jamming within the nose section.

Further and additional objects will appear from the description, accompanying drawings and appended claims.

In accordance with one embodiment of the invention, a nose section for a powered fastener-driving tool is provided which includes a fixedly mounted inner plate, and a removable outer plate which is mounted in face-to-face relation on the inner plate. The plates cooperate with one another to form an elongated guideway into which the fasteners are successively fed and from which they are subsequently discharged by a reciprocating driver element. Overlying the outer plate and mounted for slidable movement thereon is a guard piece which is adapted to cooperate with a safety device to render the trigger for the tool either operative or inoperative depending upon the relative position of adjustment of the guard piece with respect to the outer plate. A pair of adjustable arms are provided which overlie the guard piece and, when in one position of adjustment, resiliently maintain the inner and outer plates in assembled face-to-face relation.

DESCRIPTION

For a more complete understanding of the invention, reference should be made to the drawings wherein:

FIG. 1 is a fragmentary front perspective view of a powered fastener-driving tool incorporating one embodiment of the improved nose section;

FIG. 2 is similar to FIG. 1 but showing one of the adjustable arms in a released position with respect to the guard piece;

FIG. 3 is an enlarged fragmantary side elevational view partially in section of the nose section shown in FIG. 1.

FIG. 4 is an enlarged fragmentary front elevational view of the nose section of FIG. 3;

FIG. 5 is a sectional view taken along line 5--5 of FIG. 4;

FIG. 6 is an exploded perspective view of the guard piece, the adjustable arms and the outer plate of the nose section of FIG. 4.

Referring to FIGS. 1 and 2, a pneumatically powered fastener-driving tool T is shown which includes a housing 10 having a rearwardly extending handle 11 and a magazine 12 which accommodates a plurality of fasteners F, see FIG. 3. Depending from the underside of the housing is a nose section 13. Mounted for reciprocatory movement within the housing is a driver piston, which includes a depending rod or blade 14. The blade is adapted to engage a fastener and cause the latter to be discharged from the lower end of the nose section into the workpiece, not shown.

Carried by the handle 11 is a trigger, not shown, which is adapted to be manually actuated. Cooperating with the trigger is a safety mechanism 15 which includes a release rod 16 slidably mounted on the side of the housing. The release rod, when moved upwardly to its fullest extent, enables the manually depressed trigger to be operative causing compressed air to impinge against the driver piston moving same through a drive stroke. The operation of the safety mechanism in conjunction with the trigger is well known in the art.

The nose section 13 includes an inner plate 17 which is fixedly secured to the end 12a of the magazine 12 by a plurality of bolts 18, see FIG. 4. Plate 17 is provided with a passageway 20 through which the fasteners successively pass from the magazine 12. The shape and size of the passageway will depend upon the type of fasteners being driven by the tool. In the illustrated embodiment, the tool is adapted to drive staples, thus the passageway 20 has an inverted U-shape.

Removably mounted on inner plate 17 and in face-to-face relation therewith is an outer plate 21, see FIG. 5 which is adapted to cooperate with plate 17 so as to form an elongated guideway 22 which is aligned with and accommodates the portion of the driver blade 14 which projects from the lower end of the housing 10. The surface of the outer plate 21 in contact with the inner plate 17 is provided with an elongated groove 23, see FIG. 6, which extends the full height of the plate. In certain instances, the guideway may be formed by a groove formed in the inner plate, or by a pair of complementary grooves formed in both the inner and outer plates. As in the case of the passageway 20 formed in the inner plate 17, the shape and size of the guideway 22 will depend upon the type of fastener being driven by the tool T.

Partially encompassing the outer plate 21 and being slidably mounted thereon is a guard piece 24. As seen in FIGS. 4 and 5, the guard piece is preferably of unitary construction and includes a center section 25 in which are formed a pair of elongated pockets 26 which in the illustrated embodiment constitutes elongated, substantially parallel, vertically extending slots.

Extending rearwardly from opposite sides of the center section 25 are side flanges 27. The inner edges 27a of the flanges are offset and slidably engage the back side of the outer plate 21, see FIG. 5. One side of the center section 25 also includes a rearwardly extending finger 28, see FIG. 3 which is adapted to engage the lower end of the trigger-actuating release rod 16. The release rod 16 and the guard piece are biased by any suitable means to assume a down position -- that is to say, the lower end 24a of the guard piece 24 projects beyond the underside of the inner and outer plates 17 and 21, respectively. This arrangement constitutes a safety feature requiring that the lower end 24a of the guard piece be pressed against the surface of the workpiece with sufficient force so as to cause the guard piece and in turn the release rod to be pushed upwardly to their fullest extent thereby enabling the trigger to be operative when it is manually depressed. Such a safety feature is common on many types of powered tools presently available on the market.

The inner and outer plates 17 and 21 are resiliently held in assembled face-to-face relation by a pair of springlike arms 30 and 31. Each arm is of like construction and has an inner end 32 which is offset and extends into a pocket P formed in the end 12a of the magazine 12. The opposide end 33 of the arm 30 or 31 is also offset in the same direction as end 32 and is adapted to overlie the exposed surface of the center section 25 of the guard piece 24, see FIGS. 4 and 5. End 33 is further offset so as to form a projection 33a, which is adapted to extend through the corresponding slot 26 formed in the guard piece and resiliently engage the outer plate 21. Thus, the inner and outer plates 17 and 21 are resiliently clamped together between the ends 32 and 33 of each arm 30 and 31.

The inner end 32 of each arm is provided with an enlarged opening 32a through which extends the shank of a retaining pin 34 carried by the end 12a of the magazine 12. The pin 34 cooperates with the arm end 32 so as to provide a fulcrum about which the arm is adapted to pivot and also the pin prevents the arm from becoming disassembled from the end of the magazine 12, when the arm is in a release position, see FIGS. 2 and 5. The enlarged opening 32a in the arm end 32 is oversized relative to the diameter of the pin shank 34 so as to permit the arm to pivot to the release position shown in phantom lines in FIG. 5. Movement of the arms to the open positions may be readily accomplished by inserting the end of a screwdriver or the like into the space S formed between the side of the magazine end portion 12a and a center segment 35 of each arm and then prying the arm segment laterally outwardly. To move the arms into operative position merely requires both arms being manually squeezed together whereby the outer ends 33 of the arms will slide over the exposed surface of the center section 25 of guard piece until the projections 33a become aligned with the slots 26 whereupon the projections will automatically extend through the slots and resiliently engage the outer plate 21 as shown in FIG. 5.

Because of the resilient gripping of the plates together by the arms 30 and 31, the outer plate 21, if necessary, will automatically spring outwardly a slight amount causing enlargement of the guideway in the event there is a predetermined pressure buildup between the plates caused by the driver element engaging a misaligned fastener within the guideway. Thus, by reason of this relative movement by the outer plate, the plates are in effect self-clearing. In certain prior nose sections a pressure buildup caused by a jamming situation resulted in the components of the nose section fragmenting producing a hazardous situation.

The size and shape of the various components comprising the improved nose section may be varied from that shown without departing from the scope of the invention.

Thus, it will be seen that a nose section has been provided wherein the components thereof may be readily assembled and disassembled by a simple manual manipulation without requiring special tools. The nose section is possessed of self-clearing capabilities and thus, materially reduces the incidents of jamming. The nose section is of simple design and yet is capable of automatically preventing serious pressure buildup within the nose section.

Claims

I claim:

1. In a powered fastener-driving tool having a housing, a fastener-magazine and feed assembly associated with said housing and having a discharge end thereof disposed adjacent the underside of the housing, a reciprocating driver element mounted within the housing and having an end portion thereof protruding from the underside of the housing; a nose section mountable on the underside of the housing for accommodating the protruding end portion of the driver element and the discharge end of the fastener-magazine and feed assembly, said nose section comprising an inner plate fixedly mountable on the discharge end of the fastener-magazine and feed assembly, said inner plate having a passageway through which fasteners intermittently pass from the fastener-magazine and feed assembly, an outer plate disposed in face-to-face relation with said inner plate and cooperating therewith to form an elongated guideway for the protruding end portion of the driver element, a guard piece carried by said outer plate and substantially overlying the exterior of said outer plate and being slidably movable relative thereto between extended and retracted positions with respect to the underside of the housing, and resilient means adjustably carried on a fixed part of the tool and adapted to be manually manipulated between first and second positions and, when in the first position, having a portion thereof overlying the exterior of said guard piece, and resiliently engaging and retaining said outer plate in face-to-face relation with said inner plate, and, when in the second position, being disengaged from said outer plate whereby said guard piece and outer plate are disassembled relative to said inner plate.

2. The nose section of claim 1 wherein said resilient means, when in said first position, permitting movement of said guard piece and outer plate as a unit away from said inner plate to effect temporary enlargement of the guideway only upon a predetermined lateral force being developed within the guideway when the driver element is moving through a drive stroke within the housing.

3. The nose section of claim 1 wherein said resilient means comprises a pair of spring-like substantially C-shaped arms having inner ends adapted to be adjustably connected to and disposed on opposite sides of the fastener-magazine and feed assembly, and outer ends resiliently engaging and overlying corresponding exterior portions of said outer plate when said resilient means is manually manipulated to the first position; said guard piece being provided with elongated substantially parallel slots through which portions of the outer ends of the arms extend and resiliently engage the exterior of the outer plate whereby said outer and inner plates are resiliently gripped between the ends of the arms and retained in said face-to-face relation.