GB2024691A

GB2024691A - Nail driving tool

Info

Publication number: GB2024691A
Application number: GB7924401A
Authority: GB
Original assignee: Duo Fast Corp
Current assignee: Duo Fast Corp
Priority date: 1978-07-05
Filing date: 1979-07-12
Publication date: 1980-01-16
Also published as: SE441991B; ES482248A1; SE7905833L; FR2430294A1; JPS6362352B2; IT7949641A0; DE2926881C2; JPS5511796A; IT1118877B; DE2926881A1; GB2024691B; CA1093753A; FR2430294B1

Abstract

An improved electric fastener driving tool (10) includes a body (12) having ahead (14) and a handle (16) and a fastener magazine (18) pivotally connected to the body. A push button (62) for energizing the tool is engageable by a safety mechanism (64) to prevent actuation. The safety mechanism is moved out of engagement with the push button (as shown) upon pivoting of the magazine about the pivot (20) when the tool is applied to the workpiece. The magazine includes a pusher assembly (122) defined in part by half portions (126) of an elongated tube joined together to define a gap which holds nails (130). A pusher (128) is slidably mounted within the gap and biased to push the nails (130) toward the nose of the tool. The magazine also includes a fastener track (164) that includes a reduced portion (171) and an enlarged portion (172) to accommodate nails of different sizes. A V-shaped shoe (178) is releasably attached to the bottom portion of the magazine for use with a V-grooved workpiece and has a raised portion (184) at one end which may be positioned adjacent the head, by reversing the shoe, to prevent the striker (28) engaging and damaging the V-groove of the workpiece. The shoe may be replaced by a flat bottomed shoe when the tool is to be used with a flat workpiece. <IMAGE>

Description

SPECIFICATION Improvements in electrical fastener driving tools The present invention comprises improvements in electric fastener driving tools.

Electric tools for driving fasteners such as brads, staples and the like are well known and widely used.

Examples of tools of this character developed in the past may be found in U. S. Patents Nos. 3,141,171; 3,172,121; 3,179,866; 3,434,026; and 4,005,812. Such tools commonly include a housing with a handle portion and a head portion. The head portion contains a solenoid winding for accelerating an armature. Typically, a conrol circuit for energizing the winding is operated by a switch in the handle portion. A magazine is carried by the base of the head portion and by the handle for introducing fasteners into a drive track to be driven by a driver blade supported by the armature.

The object of the present invention is to provide an improved electric fastener driving tool of this kind.

The present invention provides a fastener driving tool for driving fasteners having heads and shanks into a workpiece comprising a housing, a driver, a power unit for actuating the driver, a magazine for supplying fasteners to the driver, the magazine including guide means for slidably supporting fasteners and a pusher for advancing fasteners toward the driver, said guide means comprising a bifurcated tube including first and second guide members in the form of elongated tubular segments held in spaced relation to define a gap for fasteners which are to be driven by the tool therebetween, and said pusher means being slidably secured to, and movable in, the longitudinal direction in the gap.

The fastener driving tool may further comprise biasing means mounted within said tube for biasing said pusher to advance fasteners positioned in said gap.

Said pusher may include a planar portion coinciding with said gap and extending radially beyond the tube, an aperture in said planar portion, and a sleeve in said aperture slidably related to the tube.

The magazine may include a housing having a V-shaped lower portion aligned with said gap for supporting the tips of fasteners positioned in said gap.

The magazine may include a track structure for slidably receiving the heads of fasteners positioned in said gap, said track structure including a portion of reduced transverse dimension for slidably receiving the fastener shanks.

The track structure may include a pair of spaced apart head guiding portions larger than said reduced portion for slidably receiving heads of fasteners of different lengths positioned in said gap.

The fastener driving tool may further comprise a shoe removably attached to the magazine housing for engaging a workpiece.

The shoe may be elongated and have a V-shaped workpiece engaging surface for engaging a Vgrooved workpiece.

Alternatively, the shoe may be elongated and have a flatworkpiece engaging surface for engaging a flat workpiece.

The shoe may be thicker at one end than at the other and be reversibly engaged with the magazine for altering the distance between the driver and the workpiece.

The fastener driving tool may further comprise a manually actuated control controlling the power unit and movable from a first position into a second position to effect driving of a fastener by the power unit, workpiece engageable means movable by engagement with the workpiece, and a detent means acutated by the workpiece engageable means and coupled to the manually actuated conrol alternatively to lock the manually actuated means in said first position and to free said manually actuated means for movement from said first position to said second position, said detent means including both a detent portion for locking the manually actuated control and a resilient biasing portion formed integral with the detent portion.

The fastener driving tool may include cam means for engaging the detent means and operable to move said detent portion against the bias of said resilient biasing portion to release the manually actuated control for movement to said second position.

Said workpiece engageable means may include the magazine.

A specific embodiment of the present invention will now be described by way of example, and not by way of limitation, with reference to the accompanying drawings in which: Figure 1 is a vertical side view of a tool in accordance with the present invention; Figure2 is an enlarged view of a nose portion of the tool; Figure 3 is a view taken along line 3-3 of Figure 2; Figure 4 is a view taken along line 4-4 of Figure 3; Figure 5 is a botton view of the tool; Figure 6 is a view taken along line 6-6 in Figure 3; Figure 7 is a view taken along line 7-7 in Figure 3; Figure 8 is a view taken along line 8-8 in Figure 3; Figure 9 is a view taken along line 9-9 in Figure 3; Figure 10 is a partial view of a portion of a magazine housing and a shoe incorporated in the tool;; Figure 11 is a partial view of the shoe secured to the magazine housing; Flgure 12 is a view taken along line 12-12 of Figure 3; Figure 13 is an exploded view of a pusher assembly of the tool; Figure 14 is a fragmentary view of a switch plunger and safety mechanism of the tool; Figure 15is a view taken along lines 15-15 in Figure 14; Figure 16 is a perspective fragmentary view of a safety member of the tool; Figure 17 is a fragmentary cross-sectional view of a magazine assembly of the tool; Figure 18 is a fragmentary view of the magazine housing and shoe attached thereto; Figure 19 is a partial view of another embodiment of a shoe intended to be attached to the magazine housing; and Figure 20 is an enlarged exploded view of the nose assembly of the tool.

Having reference now to the accompanying drawings and initially to Figure 1, the electric fastener tool is designated as a whole by the reference numeral 10.

The tool 10 is designed for portable hand held use and includes a housing or body generally designated as 12 having a head portion 14 and a handle portion 16 that is adapted to be grasped by the hand of the user. A magazine assembly designated by the reference numeral 18 is pivotally mounted to the handle portion 16 by a pivot pin 20 and to the nose portion 14 by a vertical sliding connection generally designated by the reference numeral 22. The magazine assembly 18 is adapted to contain a supply of fasteners that are to be driven upon manual actuation of the trigger in the form of the push button 24.

The tool 10 is actuated electrically and includes in the nose portion 14 a solenoid 26 (Figure 3). A driving blade or driver 28 is secured to the armature 30 of the solenoid 26. The armature 30 is biased in an upward position by a spring 32. The drive blade 28 is reciprocated by the solenoid 26 within a drive track 34 defined between front 36 and rear 38 nose portions (Figure 2). A best illustrated in Figure 3, the front 36 and rear 38 nose portions diverge at the upper end adjacent the solenoid 26 as a result of recesses 40 fabricated in the nose portions 36 and 38 (Figure 20). This is essential since the nose portions 36 and 38 are secured to the magazine assembly 18 by a spring clip 42 and are pivoted with the magazine 18.In order to prevent binding of the driver blade 28 within the drive track 34 upon pivoting of the magazine assembly 18, the recesses 40 at the upper end of the track 34 are necessary. The driver 28 in the inoperative mode of the tool, however, extends into the narrow portion of the drive track 34 such that it is not loosely held and subject to damage during transportation or handling ofthetool 10.

The magazine assembly 18 comprises a frame or housing 44 that includes a lower V-shaped portion 46 (Figure 8). The top portion of the frame 44 is open and a channel 48 is mounted onto and between the sides of the frame 44. The frame 44 includes two upwardly extending connecting portions 50 that are pivotally secured to depending extensions 52 of the handle portion 16 by the pivot pin 20. The magazine frame 44 also includes upward standing flanges 54 at its forward end that include a slotted aperture 56 through which extends a fastener or pin 58. The pin 58 is mounted within an aperture defined in a depending portion 60 of the nose portion 14 so that the pin 58 is not movable relative to the housing; however, due to the slotted aperture 56 in the upstanding flange 54, the frame 44 and thus the magazine assembly 18 moves vertically relative to the housing 12.This connection at the nose portion 44 in combination with the pivot connection at the pin 20 allows the magazine assembly 18 to pivot relative to the housing 12 of the tool 10. Consequently, upon placement of the tool 10 onto a workpiece, the magazine assembly 18 pivots about the pin 20 until engagement of the pin 58 with the lower end of the slotted aperture 56.

This pivoting action of the magazine assembly 18 also prevents skip off. Skip off results from the recoil of the tool 10 after firing. The recoil is often sufficient to move or "skip" the tool off the workpiece resulting in incomplete driving of the fastener into the workpiece. The pivoting action of the magazine assembly absorbs this recoil and prevents skip off.

This prevention pivoting action may also be accomplished by pivoting only that portion of the assembly adjacent the drive track 34.

The pivoting movement of the magazine 18 is employed to actuate a safety mechanism generally designated by the reference numeral 62 (Figure 3).

The safety mechanism 62 includes an elongated rod 64 including a lower end 66 that abutts against the top of the channel 48 of the magazine assembly 18.

The rod 64 is mounted within an elongated aperture 68 defined in the nose portion 14 of the housing 12.

A bottom portion 70 of the aperture 68 is enlarged to house a spring 72 surrounding the rod 64. The spring 72 abutts against the upper end of the portion 70 and against the top of the channel 48, thus providing a bias tending to pivot the magazine assembly 18 downwardly to a first position. In this first position of the magazine 18, the safety mechanism 62 prevents actuation ofthetool 10 (Figure 14).

The safety mechanism 62 includes a spring member 74 defined on rod portion 64. The spring 74 includes a cam surface 76, a curved surface portion 78, a sloped or inclined surface portion 80 and a bottom edge portion 81. The curved portion 78 engages a corresponding curved surface portion 82 of the housing. The housing includes an aperture 84 adjacent the portion 82 within which the trigger button 24 is slideably mounted. The trigger button 24 also includes a detent or flange 86 that engages the edge 81 of the spring portion 74 preventing actuation and a flange 88 that engages a reduced portion 90 of the aperture 84 thus preventing the button 24 from falling out of the aperture 84.

A plunger 92 is slideably mounted within the trigger button 24 and includes a nose 94 adapted to engage a plunger 96 of a microswitch 98. The microswitch 98 is connected to a power cord 100 by leads 102 and 104 (Figure 1) which are connected to a power source providing energy for operating the tool 10. A first spring 106 is positioned within the trigger button 22 and beneath the plunger 92 tending to bias the plunger 92 into engagement with the plunger 96 of the microswitch 98. A second spring 108 surrounds the plunger 92 and engages the microswitch housing 98 tending to bias the plunger 92 and the trigger button 24 away from the micros witch 98. The spring 108 O & is larger than the spring 94 such that when not engaged, the trigger button 24 and the plunger 98 are biased by the spring 108 out of engagement with the plunger 96 of the microswitch 98.

In order to energize the tool 10, the operator must first place the magazine 18 against the workpiece thus pivoting the magazine 18 about the pivot pin 20 and moving the rod 64 and spring 74 upward. This causes the cam surface 78 to engage the curved surface 82 bending the spring 74 and causing the surface 81 to move out of engagement with the flange 86. The operator of the tool 10 may then depress the trigger button 24 contacting the plunger 96 and energizing the switch 98 to drive the blade 28 though a driving stroke.

As an added safety feature and to ground the magazine 18, the magazine housing 44 includes a ground tab 112 that is electrically connected by means of a fastener 1 14to a grounding clip 116. The grounding clip 116 is flexible and includes a flange 118 that is coupled to a ground wire 120 leading frm the power cord 100 (Figure 3). Accordingly, upon pivoting of the magazine assembly 18, the grounding clip 116 flexes thus maintaining the grounding connection desired.

Turning now to the magazine assembly 18, this includes a pusher assembly generally designated by the reference numeral 122 (Figure 13). The pusher assembly 122 includes first 124 and second 126 identical elongated tubular members that are hald or bifurcated portions of an elongated tube. The tubular portions 124 and 126 serve as a guide for a pusher 128 and fasteners 130 that are mounted within the magazine assembly 18. The pusher 128 is of a rectangular configuration including legs 129 and inclined surfaces 130 and 132. The pusher 128 also includes a rectangular aperture 134 that allows the pusher 128 to be slidingly coupled to the guides 124 and 126.

To assemble the pusher assembly 122, a first pusher sleeve 136 is passed over and around first ends 138 and 140 ofthe guides 124 and 126, respectively, and secured in a manner such that the guides 124 and 126 are spaced slightly apart to define a gap 142 therebetween. (See, for example, Figures 17 and 8). A spring 144 is positioned within and between the guides 124 and 126 with an end engaging a stud 146 that serves to connect a pusher lock 148to the ends 138 and 140 ofthe guides 124 and 126 and to maintain the guides 124 and 126 in spaced relationship. The pusher lock 148 is secured within slots 151 and 152 fabricated in the guides 124 and 126, respectively.

The pusher 128 is mounted within the gap 142 and is biased by the spring 144 away from the stud 146.

To mount the pusher 128 within the gap 142, a second pusher sleeve 150 passes through the aperture 134 and encircles the guides 124 and 126 thus joining them together (see, for example, Figure 3).

The guides 124 and 126 includes flanges 154 on the ends thereof that are engaged by the pusher sleeve 150 thus preventing the pusher 128 from being biased by the spring 148 beyond the length of the guides 124 and 126.

The pusher assembly 122 is positioned within the frame 44 of the magazine assembly 18 and is supported at one end by the pusher lock 148 that includes a clip 156 that is removably attached in an aperture 158 fabricated in the channel 48. The pusher assembly 122 once mounted in the magazine assembly 18 is supported at the other end by the pusher 128 on the leg portions 129 that engage V-shaped section 46 of the frame 44.

Before operating the tool 10, a stick of fasteners 130 is positioned within in the magazine 18 in a manner such that the ends 160 of the fasteners are engaged and are supported by the apex of the V-section 46 of the frame 44 (Figure 7). The magazine 18 may hold fasteners of two different sizes through the use of a track generally designated by the reference numeral 164. The track 164 is defined by first 166 and second 168 guide members that are secured to the channel 48 by a plurality of rivets 170.

Upon being secured to the channel 48, the guides 166 and 168 define a reduced portion 171 and an enlarged portion 172. If long fasteners 130 are employed (see, for example, Figure 7), the head 162 of the fastener 130 extends above and is guided by the reduced portion 171 of the track 164. If a shorter fastener such as 130A in Figure 17 is desired to be driven by the tool 10, the head 176 of the fastener 130A is guided by the enlarged portion 172.

The fasteners 130 and 130A are fed through the drive track 134 by the pusher 128. Once the last fastener 130 or 1 30A has been driven, the front edge of the pusher 28 is moved into the drive track 34 by the spring 144. If the tool 10 is fired, the driver 28 will engage one of the leading inclinded surfaces 131 or 132 and this engagement moves the pusher 128 out of the drive track 34 against the bias of the spring 144 thus preventing damage to the pusher 128. Once the operator of the tool 10 notices that no further fasteners 130 or 130A are being driven by the tool, operation of the tool 10 can be terminated and a new stick of fasteners 130 or 130A may be inserted into the magazine assembly 18.

The tool 10 may be used on grooved workpieces such as panelling in which it is desired to drive the fasteners into the grooves of the panelling. This is the reason that frame 44 of the magazine assembly 18 includes the V-shaped section 46. The nose of the tool is also V-shaped at its lower end in order to be inserted within the grooves of the panelling. Due to the fact that the workpiece such as panelling may be of softer material than others, it is often undesirable to allow the driver blade 128 to engage the workpiece since it would leave a dent. Accordingly, a shoe generally designated by the reference numeral 178 is included.The shoe 178 is of the same general configuration as the magazine frame 44 and is intended to be releaseably secured to the frame 44 through the use of detents 180 fabricated on the inner peripheral surface of the shoe 178 that are inserted into corresponding apertures 182 fabricated in the frame 44. The shoe 178 is made of resilient material, thus allowing a spring like connection once the detents 180 are snapped into the apertures 180.

To prevent damage to a workpiece, the shoe 178 includes a raised portion 184 (see, for example, Figures 1 and 11). The shoe 178 may be secured to the frame 44 with the raised portion 184 adjacent to the nose (Figure 11). In this position, the raised portion 184 engages the workpiece maintaining the nose portions 36 and 38 spaced slightly above the workpiece such that the driver 28 does not engage the workpiece upon completion of its full stroke, thus avoiding unslightly dents in the workpiece.

If it is desired to use the tool 10 on a flat ungrooved workpiece, another shoe such as the shoe 178A may be employed. This shoe 178A includes an inner peripheral V-shaped configuration conforming to the frame 44 and detents 180A that are to be inserted into the apertures 182 in the frame 44; however, the lower surface 184 of the shoe 178 is flat thus allowing the tool 10 to be placed on top of a flat workpiece.

There has been described with reference to the accompanying drawings, a tool that is light in weight, is easily and economically manufactured and includes interchangeable shoe members that may be used to allow the tool to drive fasteners into the grooves of a grooved workpiece or a flat workpiece and to vary the depth into which the fasteners are driven.

The tool has a safety mechanism that prevents energization of the tool until the tool engages a workpiece.

The magazine assembly includes a fastener's track that may support and guide fasteners of different sizes.

The electric fastener driver includes a body defining a head portion and a handle portion. The body is of a clam shell configuration formed of two similar plastic body parts including integral walls forming a solenoind chamber in the head portion and forming a mounting position for a switch and related circuitry in the handle portion. The magazine for supplying fasteners to be driven is pivotally supported on the handle portion. The driver is secured to the solenoid for reciprocation in a drive track defined by the nose portion. Energization of the solenoid and thus of the tool is controlled by a switch that is manually actuated through the employment of a plunger reciprocally mounted in the handle portion.

The safety mechanism prevents depression of the plunger until the tool has been placed against the work-piece. The safety is actuated to release the plunger by the pivoting movement of the magazine assembly upon engagement of the tool with the workpiece. More specifically, upon engagement of the tool with the workpiece, the magazine assembly is pivoted from a first position to a second position.

The safety mechanism is coupled to the magazine assembly and thus moves from a first to a second position in conjunction with the pivoting movement of the magazine assembly. In the second position, the safety mechanism is out of engagement with the plunger allowing actuation. The magazine assembly also includes a track that supports and guides the fasteners of different sizes.

The pusher assembly for advancing fasteners to the drive track of the tool is included in the magazine assembly.

Claims

1. A fastener driving tool for driving fasteners having heads and shanks into a workpiece comprising a housing, a driver, a power unit for actuating the driver, a magazine for supplying fasteners to the driver, the magazine including guide means for slidably supporting fasteners and a pusher for advancing fasteners toward the driver, said guide means comprising a birfurcated tube including first and second guide members in the form of elongated tubular segments held in spaced relation to define a gap for fasteners which are to be driven by the tool therebetween, and said pusher means being slidably secured to, and movable in, the longitudinal direction in the gap.

2. Afastener driving tool as claimed in Claim 1 further comprising biasing means mounted within said tube for biasing said pusher to advance fasteners positioned in said gap.

3. A fastener driving tool as claimed in Claim 2, said pusher including a planar portion coinciding with said gap and extending radially beyond the tube, an aperture in said planar portion, and a sleeve in said aperture slideably related to the tube.

4. Afastener driving tool as claimed in any preceding Claim, said magazine including a housing having a V-shaped lower portion aligned with said gap for supporting the tips of fasteners positioned in said gap.

5. A fastener driving tool as claimed in any preceding claim, said magazine including a track structure for slidably receiving the heads of fasteners positioned in said gap, said track structure including a portion of reduced transverse dimension for slidably receiving the fastener shanks.

6. A fastener driving tool as claimed in Claim 5, said track structure including a pair of spaced apart head guiding portions larger than said reduced portion for slidably receiving heads of fasteners of different lengths positioned in said gap.

7. Afastener driving tool as claimed in any preceding claim further comprising a shoe removably attached to the magazine housing for engaging workpiece.

8. A fastener driving tool as claimed in Claim 7, said shoe being elongated and having a V-shaped workpiece engaging surface for engaging a Vgrooved workpiece.

9. Afastener driving tool as claimed in Claim 7, said shoe being elongated and having a flat workpiece engaging surface for engaging a flat workpiece.

10. A fastener driving tool as claimed in Claim 8 or 9, said shoe being thicker at one end than at the other and being reversibly engaged with the magazine for altering the distance between the driver and the workpiece.

11. A fastener driving tool as claimed in any preceding Claim, further comprising a manually actuated control controlling the power unit and movable from a first position into a second position to effect driving of a fastener by the power unit, workpiece engageable means movable by engagement with the workpiece, and a detent means actuated by the workpiece engageable means and coupled to the manually actuated control alternatively to lock the manually actuated means in said first position and to free said manually actuated means for movement from said first position to said second position, said detent means including both a detent portion for locking the manually actuated control and a resilient biasing portion formed integral with the detent portion.

12. A fastener driving tool as claimed in Claim 11 including cam means for engaging the detent means and operable to move said detent portion againstthe bias of said resilient biasing portion to release the manually actuated control for movement to said second position.

13. Afastener driving tool as claimed in Claim 11 or 12, said workpiece engageable means including *e magazine.

14. Afastener driving tool constructed and arranged to operate substantially as hereinbefore described with reference to the accompanying drawings.