The invention generally relates to magazines for nail guns and, more particularly, to a combination magazine and loader for supplying, separating and loading the leading member from a supply of fasteners or tacks of the type characterized by commonly-owned U.S. Pat. No. 5,927,922, entitled “Tack, Hammer Tacker Therefor, and Method,” as well as commonly-owned U.S. Pat. No. 7,228,998, entitled “Hammer Tacker, and Tack Therefor,” the disclosures of which are incorporated fully herein by this reference.
Briefly, the tack disclosed in those patents has an especially broad flat head to provide a large surface area particularly effective for fastening soft, thin, membrane materials.
It is an object of the present invention to provide consumers of this tack with a magazine option other than the known manual hammer tacker magazines as disclosed in the commonly-owned patents, and in favor of manual, electric, pneumatic, or gas-powered nail guns outfitted with a magazine in accordance with the invention.
A number of additional features and objects will be apparent in connection with the following discussion of the preferred embodiments and examples with reference to the drawings.
There are shown in the drawings certain exemplary embodiments of the invention as presently preferred. It should be understood that the invention is not limited to the embodiments disclosed as examples, and is capable of variation within the scope of the skills of a person having ordinary skill in the art to which the invention pertains. In the drawings,
The nail gun magazine 100 accepts a supply of fasteners 104 arranged in a stack 106 (see, eg.,
An example use of the combination magazine 100 in accordance with the invention and nail gun 102 of the prior art includes, without limitation, roofing jobs. A roofer might tack a row of shingles with such fasteners or “tacks.” Other example uses include without limitation drying in a roof with felt, or applying a house wrap (ie., a vapor barrier) for exterior walls or also hanging dry wall or sheetrock for interior walls, and so on.
This representative, and non-limiting, example of a prior art nail gun 102 comprises a modified PASLODE® 18 Gauge Cordless Finish Nailer (Part No. 901000), a product of Illinois Tool Works, Inc.
Again, the nail gun 102 was modified, and the modifications include the following. The stock magazine (not shown) of the PASLODE® nail gun 102 has been removed. The stock magazine was designed to be loaded with and feed 18 gauge brad nails (eg., finish nails, and not shown) in lengths from ⅝ths-inch to two inches long (˜1⅝ to five cm long).
Finish nails are the opposite of tacks. Finish nails are thin, slender fasteners, with especially tiny heads. The head diameter might not even be twice the shank diameter. The stock magazine stood these nails straight up, and fed them straight in: —in other words, the conveyance of these nails in the stock magazine was the opposite of being stacked.
That is, if a straight stack is envisioned as being a vertical column, then in contrast the conveyance of the nails in the stock magazine was in a horizontal row. For this and other reasons, the stock magazine of the PASLODE® nail gun 102 would offer no opportunity for modification for the conveyance of tacks 104 in a stack 106, as here. Hence it was dispensed with altogether.
Also modified was the handle of the PASLODE® nail gun 102 (hereinafter, simply “nail gun 102,” except where context means other brands and types too). The nail gun 102's handle as shown in the drawings is a truncated, lopped off version of the stock design. In fact, much of the lopped off part of the handle comprised not only a transition into the stock magazine but also a battery pack (it too is not shown). The battery pack has been retained, except that it has been separated from the stock magazine—which was dispensed with—and was remounted on the side of the nail gun 102 (but this is not shown).
Moreover, the stock safety trip (or work-contacting element) has been removed. Needless to say, the stock safety trip was a safety device. It looked like and had a (former) location of what might be envisioned as a stubby, pistol barrel. The stock safety trip was where the nail was shot out of the stock magazine. As a matter of safety, the PASLODE® nail gun 102 does not fire unless the safety trip was placed against the work, and then pressed into it. The safety trip would not pierce the work but, instead, it depressed into the nail gun 102, pushing an elongated linkage back into the body of the nail gun 102, to switch ON an electric circuit. The switch tripped a series of events to transpire. A fan motor started to blow air (hence the need for a substantial battery pack) as injectors would inject fuel in the air stream to charge a combustion chamber. Only then would squeezing the trigger ignite the fuel/air mixture in the combustion chamber. That in turn would blast the piston down on the nail, hence driving the nail.
The safety trip had another function after that. After use, the user would lift the nail gun 102, and the safety trip would restore itself to its original non-depressed state. This would cause the combustion chamber to open, the fan was allowed to continue to run for a time, so as to exhaust the hot gases and cool internal components. Nonetheless, the stock safety trip (or work-contacting element) was removed.
This PASLODE® nail gun 102 is typical of a category of mechanized nail guns, a category more generally known as impulse hammers. These are gas-powered nail guns that detonate combustible fuel in an internal-combustion piston chamber (piston chamber not shown but, for a piston, indicated by reference numeral 108, see
Whereas the nail gun magazine 100 in accordance with the invention is inventive in connection with stacked fasteners, it can be readily adapted for use with other types of mechanized nail guns and/or driving tools. Thus, it is an object of the present invention to provide consumers of this tack with a magazine option other than the known manual hammer tacker magazines as disclosed in the commonly-owned patents, and in favor of manual, electric, pneumatic, or gas-powered nail guns outfitted with the magazine 100 in accordance with the invention. It is merely a design preference to illustrate the inventive nail gun magazine 100 with a gas-powered (cordless) impulse nail gun because such is truly a deluxe, high end tool in the industry.
The tack 104 is preferably produced from relatively light gauge sheet metal. A preferred embodiment of the tack 104 has a head 110 measuring one inch (twenty-five mm) square. The head 110 is bounded by four straight edges and four rounded corners. The tack 104 has a shank 112 extending down from the head 110 that is between about three-fourths an inch (nineteen mm) and seven-eighths an inch (twenty-two mm) long. The preferred gauge for the parent sheet metal might be between twenty and twenty-four gauge, although other sizes can be equally adapted for the purpose, to make larger or smaller—or stiffer or whatever—tacks 104 as desired.
The shank 112 of the tack 104 is lanced out of the tack head 110. The shank 112 has a rounded-V cross-section to improve stiffness, and is pointed at the end to improve piercing. The consequence of lancing the shank 112 out of the head 110 is, to leave behind a slot in the head 110 of the tack 104, which originates at about the head 110's center, and extends out through an open end in one corner.
It is preferred that the tacks 104 are advanced in the plane of their heads 110. It is furthermore preferred if the leading part of the tack head 110 is one of the corners. That is, for each tack head 110, the leading corner is the one opposite the corner with the slot-opening. Each tack head 110 has a notch 114 in its leading corner. Each tack 104 is inserted on top of the stack having its head 110 flush against the head 110 of the tack 104 below it, and its shank 112 nested flush in the slot and against the shank 112 of the tack 104 below it.
The lead tack 104A adheres to the bottom of the stack 106 by virtue of numerous shanks 112 (see also
It will be noted in
In other words, the tacks 104 stack up not in a straight (vertical) column but at an angle, where each tack head 110 is axially (laterally) offset from the previous by the thickness of a tack shank 112 (plus any gap between shanks 112 if there were any, but preferably there is not). The center of geometries of all the tacks 104 define an axis for the stack 106. The rise of this axis leans over the base plane (eg., the horizontal) by the amount of axial offset between one tack 104 to the next. Like a staircase has a pitch (angle), this stack 106 has a characteristic pitch. For this stack 106, that pitch is 45°. That is, between each tack 104 and the next, the stack 106 has a pitch equal to the arctangent of the ratio of the thickness of a tack head 110 (eg., the opposite side of a right triangle) to the lateral offset due to a tack shank 112 (eg., the adjacent side). Since the tack heads and shanks 110 and 112 are products of the same sheet gauge, then their thicknesses are the same. Hence if the tacks 104 are nested ideally with no gaps between adjacent tack heads 110 and adjacent tack shanks 112, the pitch of the stack 106 is optimally the arctangent of a 1:1 incremental ratio from each tack 104 to the next, hence yielding a 45° pitch for the stack 106.
It is an aspect of the invention that the stack 106 for the magazine 100 is a highly dense mass of tacks 104. The stack density can probably be specified by numerous criteria, but two are offered here. One is, the number of tacks 104 per unit height. The other is, the percentage of surface area overlap between tack heads 110 of adjacent tacks 104 in the stack 106. For example, if two equal coins were stacked perfectly one on top the other (ie., there is no axial offset), then there would be one-hundred percent surface area overlap. But if their centers were axially offset by some amount less their common diameter (by any more than that and they would not overlap at all), there would be something less than one-hundred percent surface area overlap.
Surface area overlap can be computed from axial offset, as will be set forth below. However, for circles, the equation is a little unwieldy. Nevertheless, for small values of axial offset, there is an approximation which applies to both squares and circles, and again as will be more particularly described below.
Giving real numbers to these criteria yields the following. In consideration of number of tacks 104 per unit height, an estimate might be calculated. The unit height might be chosen to be tack head 110 diameter. Although it's not really one inch for tack heads 110, for convenience here it is assumed to be one inch. That way, the number of tacks 104 per inch would be the inverse of the thickness of one tack head 110, when given in inches. For example, consider a stack 106 of tacks 104 produced out of twenty-two gauge sheet metal (not stainless, aluminum, galvanized or other exotics, just plain steel). Twenty-two gauge sheet metal has a nominal thickness of 0.0299 inches (0.7595 mm). The inverse of 0.0299 yields a calculated value of thirty-three tack 104 heads per inch of stack height. On the other hand, counting out an inch's worth of real tacks 104 stacked together obtained a count of thirty tacks 104 per inch of stack height. Nevertheless, the manually-counted value with real twenty-two gauge tacks agrees fairly well with the calculated value.
The second criterion for specifying stack density is surface area overlap (either fractional or percentage) of adjacent tack heads 110. As a preliminary matter, the tack head 110 of tack 104 (and as better shown in
With squares being first, the tack heads 110 can be likened to thin square tiles (and solid ones, eg., the slots 112 are considered filled with solid material). The surface area overlap percentage of two square tiles stacked with their centers axially offset from each other is not only a function of axial offset between their respective centers (ie., the lateral distance the center of one is slid horizontally away from the other) but also a function of the vector of the offset. If two square tiles are tiled on top of each perfectly, then there is no axial offset (ie., the centers line right up on top of each other), and then there is also one hundred percent overlap.
Only two vectors of axial offset will be considered. One vector is when the center of one tile is offset relative to the center of the other along a bisect line parallel between two opposite sides. More simply, envision the two panes of a sliding glass door. Their relative displacement of their centers is back and forth on this one vector. The other vector is when the center of one tile is offset relative to the center of the other along a diagonal of each. This is how the tack heads 110 of stack 106 are axially offset.
So for the first vector of axial offset (eg., relative displacement between the two panes of a sliding glass door), envision the two equal square tiles held in parallel planes by tracks along their top and bottom edges. ‘Fractional’ axial offset “δ” shall be defined as the transverse displacement between centers as a ratio of side length.
Axial offset=δ=[(offset distance between centers)/(side length)]. (1)
Surface area overlap of the two tiles varies directly with one minus the axial offset.
Fractional surface area overlap=1−δ. (2)
That is, if two tiles one-inch square are tiled such that their centers are a half-inch apart when slid in parallel planes by tracks along their top and bottom edges, then the ‘fractional’ axial offset is one half, and the ‘fractional’ surface area overlap is one half.
For the second vector, envision the two square tiles being slid relative each other on their diagonals. ‘Fractional’ axial offset “δ” in this case is modified to be defined as the transverse displacement between centers as a ratio of diagonal length.
Axial offset=δ=[(offset distance between centers)/(diagonal length)]. (3)
Surface area overlap of the two tiles varies directly with the square of, one minus the axial offset.
Fractional surface area overlap=(1−δ)2. (4)
That is, if two square tiles are tiled such that their centers are a half of a diagonal apart when slid along mutually overlapping diagonals, then the ‘fractional’ axial offset is one half, and the ‘fractional’ surface area overlap is one quarter. And so on, if ‘fractional’ axial offset is one-quarter, then the ‘fractional’ surface area overlap is nine-sixteenths.
Now to turn to the case of circles. Instead of tiles, the tack heads 110 can be likened to solid coins. There is only one characteristic vector of relative displacement for coins. They are always offset along mutually overlapping diameters. ‘Fractional’ axial offset “δ” for circles shall be defined as the transverse displacement between centers as a ratio of diameter.
Axial offset=δ=[(offset distance between centers)/(diameter)]. (5)
Surface area overlap for two coins varies according to equation (6).
Table 1 below gives some sample calculations for surface area overlap percentage between two coins according to a range of ‘fractional’ axial offsets. To be clear, when two coins are stacked according to axial offset “δ” equal to one-half, that means that the centers of both coins coincide with some point on the circumference of the other.
All of the foregoing boils down to a remarkably simple proportion. When the axial offset δ is fairly small (eg., fractional axial offset δ is about 0.05 and less), then surface area overlap can be approximated as follows—and not only for the two vectors of relative displacement between squares as discussed above, but also for circles: —
Fractional surface area overlap{dot over (=)}1δ.
(For δ generally less than 0.05). (7)
As more particularly described above, the tack head 110 is formed from the outline of a square that measures one inch (25.4 mm) on the sides. The diameter across the truncated diagonal line transverse to the slot (eg., extending between the two opposite rounded corners) measures about one-and-three-sixteenths of an inch (˜30 mm). Hence this tack head 110 would have a simulated diameter somewhere between those two values. For convenience sake, the lower value (one inch or 25.4 mm) is adopted.
The same that was described about the count of tacks 104 per inch of stack 106 is true about tack head 110 axial offset per inch. Manually counting out an inch's worth of real tack heads 110 axial offset in the stack gives the same count of thirty tack heads 110 per inch of stack transverse displacement. Again, recall that the pitch of the stack is 45°. So fractional axial offset 8 is equal to the offset distance between centers of adjacent tack heads 11 normalized by division of the nominal diameter, which is chosen here to be one inch (25.4 mm) for convenience.
Simply stated, the axial offset for tack heads 110 is:
axial offset=one-thirtieth{dot over (=)}0.0333 (8)
Consequently, according to equation (7), for adjacent tack heads 110,
fractional surface area overlap{dot over (=)}1−δ=0.966 (9)
Pause can be taken now to summarize the significance of the new stacking density of tacks 104 in a stack 106 which can be served for ejection by tack magazine 100. Previously, commonly-owned patent U.S. Pat. No. 5,927,922 illustrated a procession of like tacks where density is better illustrated by
Table 2 shows better how this project has evolved, and reversed directions, trending originally to wide and wider tack head 110 spacings, to the present, representing as tightly-packed overlap as the thickness of the tack shank 112 will allow.
Hence the nail gun magazine 100 in accordance with the invention advantageously handles the loading and feeding of tacks in about a twelve-fold closer packing than the commonly-owned prior projects.
It is preferred if the pitch of the stack 106 is at least 12° (twelve degrees, and not shown). This means that the stack 106 would extend more nearly like a low ramp than it does now, as a 45° ramp. However, some large-headed fasteners have large shank diameters and relative thin head thicknesses. One common broad-headed fastener has a shank-diameter to head-thickness ratio of 4:1 (four to one). If such a common broad-headed fastener were modified to stack (to date, it is not know to have ever been modified so), then the steepest that such fastener could stack would be tan−1 (¼), which is 14° (ie., the arctangent of the ratio of, the rise the fastener's head, to the axial offset of the fastener's shank). The preference for at least 12° is just tolerance for less than ideal stacking.
It is preferred if the stacking density in terms of number of fasteners per fastener head diameter is at least eight (8). The common broad-headed fastener referred to above, were modified to stack (to date, it is not know to have ever been modified so), then the densest it would stack would nine fastener heads high for every fastener head diameter. The preference for at least eight (8) is just tolerance for less than ideal stacking.
It is preferred if the mean axial offset is at most a third (⅓rd). The common broad-headed fastener referred to above would yield this axial offset value if a slot were opened in its head all the way to its shank (not known to date to have ever been modified so). The head diameter of that fastener is only three times (3×) greater than its shank diameter.
It is preferred if the mean surface area overlap between adjacent fastener heads (and of the mean geometry of the fastener heads, ie., excluding slots or the like) is at least 40%. As shown by Table 1, that means that a round fastener head must have something in the nature of a slot into its mean geometry to allow for a lower axial offset value than is possible for a solid fastener head alone. It is more preferred still if the mean surface area overlap between adjacent fastener heads is at least 58%. This corresponds for the high value for the preferred range of mean axial offset.
As a preliminary matter,
As will be more particularly described below, the term “hub” refers to a much more elaborate construction than is ordinarily thought of by use of the term hub.
With reference to
Returning to
The drive axles 116 facilitate a linear drive or input stroke (albeit, the hub 118 does the traveling, not the drive axles 116). This causes a linear reaction stroke in the tack-loading slide 120. From the hub 118's frame of reference, the tack-loading slide 120 and the drive axles 116 cycle through linear load and release strokes relative to it. So, among other functions of the hub 118, it provides for the 90° translation between the stroke(s) of the drive axles 116 and the stroke of the tack-loading slide 120.
The foregoing will be more particularly described below, following the discussion that follows of
The magazine chamber 124 comprises an open channel oriented at a 45° angle relative to the linear stroke of slide 120.
Optionally the follower 126 and the guide sleeve 134 therefor are produced out of aluminum and, optionally in contrast to the guide studs 138 and pins 142, which might be produced out of stainless or tool steel.
The guide sleeve 134 has a pull knob 144 on its top. In use, a user might be holding the nail gun 102 in the manner of a pistol and then, simply loop the pinky finger of his or her free hand around the pull knob 144, retract the follower 126 out of the magazine chamber 124 and swing it to the swung up open position. That opens the back or breech of the magazine chamber 124. The user then inserts the stack 106 of tacks as shown and re-admits the follower 126 onto the top of the stack 106, after which the negator 128 (ie., the constant pressure coil spring) supplies the constant urging force that the follower 126 applies against the top of the stack 106.
As mentioned above in connection with
The drive axles 116 comprise a spaced pair of parallel rods affixed at one end to and projecting away from the U-shaped shoe 122. The drive axles 116 have gear formations 146 in the nature of rack teeth formed in them for most of their length. The drive axles 116 and shoe 122 are preferably produced of aluminum. As an aside,
Namely, these five are: —a spaced pair of parallel reaction rods 152; a spaced pair of parallel compression rods 154; and a strip of flat sheet metal stock that serves as the tack-loading slide 120. All five of these members are mounted spaced apart at their rear (base) ends to a base block 156. The reaction rods 152 are formed with gear formations 158 in the nature of rack teeth as shown for about the forward half of their lengths. Preferably the reaction and compression rods 152 and 154 are produced of aluminum; the tack-loading slide 120, spring steel; and the base block 156, DELRIN® or the like.
Continuing in
Referring to
Situated beneath the central block 164 is a spacer block 172 (as
The bed 174 is formed with several recesses having varying functions.
All of
The bed 174 has a broad shallow slot or channel 186 recessed in its top surface, originating in the tack ejection bore 184, and being as wide as the diameter of the tack ejection bore 184. This broad shallow channel 186 is symmetric about the longitudinal vertical plane of symmetry of the bed 174, and extends rearwardly through the bed 174 all the way through the back end thereof. This broad shallow channel serves as the slideway 186 for the tack-loading slide 120 as well as for the tack head 110 of the lead tack 104A.
The piston 108 has only been sparingly mentioned above. However, this piston 108 is a custom design to replace the stock piston in the nail gun 102 (which requires some disassembly of the nail gun 102 to do). This piston 108's ring 188 preferably matches the same size as the stock piston's, but this piston 108's shaft 190 certainly has a larger diameter, preferably something approaching ½-inch (˜twelve mm). It is preferably produced of tool steel. The piston 108's shaft 190 is drilled through with numerous lightening holes to reduce its weight. The shaft 190 terminates in an impact (hammer) surface.
To continue with the piston 108, there is a vertical bore all the way through the central and spacer blocks 164 and 172 which accepts the insertion and reversible travel of the piston 108's shaft 190. This piston shaft bore opens into the center of the tack ejection bore 184 in the bed 174. On a final note,
With the foregoing in mind, the manner of use of the nail gun magazine 100 as well as the synchronized load and release strokes of the drive axles 116 and shuttling frame 150 can now be more particularly described.
It is a preference of the invention to utilize racks and coupled pinions as a means of changing straight line motion. However, racks and coupled pinions are not the sole and exclusive means for accomplishing the same, and hence are offered merely as a non-limiting example. Indeed, the reference of D. C. Greenwood, ed., “ENGINEERING DATA FOR PRODUCT DESIGN,” McGraw-Hill Book Co., 1961, at pages 324-327, discloses at least eighteen (18) other ways to do so. The foregoing citation is incorporated by reference.
Returning to
Henceforth, the discussion shall focus on the release stroke. The load stroke was actually complete by
In short, everything is restored back to an original set position, and in readiness for a succeeding use.
The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred examples, to assess the scope of the invention in which exclusive rights are claimed.
This application claims the benefit of U.S. Provisional Application No. 61/190,706, filed Sep. 2, 2008, the disclosure of which is incorporated fully herein by this reference thereto.
Number | Name | Date | Kind |
---|---|---|---|
2994878 | Abrahamsen | Aug 1961 | A |
4089099 | Nivet | May 1978 | A |
4136810 | Bull | Jan 1979 | A |
4196836 | Becht | Apr 1980 | A |
4204625 | Glenn | May 1980 | A |
4403722 | Nikolich | Sep 1983 | A |
4483280 | Nikolich | Nov 1984 | A |
4483473 | Wagdy | Nov 1984 | A |
4483474 | Nikolich | Nov 1984 | A |
4522162 | Nikolich | Jun 1985 | A |
4585154 | Fealey et al. | Apr 1986 | A |
4815910 | Potucek | Mar 1989 | A |
4858812 | Fealey | Aug 1989 | A |
5000365 | Fealey | Mar 1991 | A |
5192012 | Schafer et al. | Mar 1993 | A |
5199625 | Dewey et al. | Apr 1993 | A |
5238167 | Howard et al. | Aug 1993 | A |
5263439 | Doherty et al. | Nov 1993 | A |
5664722 | Marks | Sep 1997 | A |
5927922 | Miller | Jul 1999 | A |
5979735 | Olvera et al. | Nov 1999 | A |
6010291 | Schwingle | Jan 2000 | A |
6131787 | Curtis | Oct 2000 | A |
6422447 | White et al. | Jul 2002 | B1 |
6443348 | Lamb | Sep 2002 | B2 |
7090455 | Lamb | Aug 2006 | B2 |
7228998 | Schulz et al. | Jun 2007 | B1 |
20060102683 | Schnell et al. | May 2006 | A1 |
20070114259 | Bromley et al. | May 2007 | A1 |
20080260496 | Parmann | Oct 2008 | A1 |
Entry |
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D.C. Greenwood. Engineering Data for Product Design. (McGraw-Hill: New York 1961). |
Section entitled “10 ways to change straight-line direction,” pp. 324-327. |
Paslode 18 Gauge Cordless Finish Nailer: Operating Manual © 2001 Illinois Tool Works. Inc. |
Paslode Cordless 18 Gauge Brad Nailer: Tool Schematic and Parts © 2006 Illinois Tool Works. Inc. |
Number | Date | Country | |
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61190706 | Sep 2008 | US |