US 3910325 A
A hand-held fastener driving gun is suspended for comparatively free horizontal and vertical movement by an arched leaf spring. The spring also supports a flexible tube for delivering fasteners to the gun and a flexible line for supplying power to the gun, the spring preventing the tube and the line from becoming tangled and kinked during movement of the gun.
Claims available in
Description (OCR text may contain errors)
1451 Oct. 7, 1975 AUTOMATIC FASTENER DRIVING MACHINE WITH HAND-HELD DRIVING GUN Primary Examiner-Al Lawrence Smith Assistant Examiner-Gary L. Smith  Inventor: Paul H. Dixon, Belvidere, Ill.
An ,A t, F -Wlf,Hbb d,L d',  Assignee: Dixon Automatic Tool, Inc., 9mg) gen or [rm 0 e u ar ey lg Volt & Osann, Ltd. Rockford, Ill.
22 Filed: Nov. 4, 1974 211 Appl. No.: 520,236
ABSTRACT A hand-held fastener driving gun is suspended for 70 2 MN 85 41 2 B1 4x4 UB7 1 7 8 m4 2 2 6 mm 4 l 4 0O 1 .c "Ur .e as l C smfw UIF HUN 555 243/17; 2 7/1 0 flexible line for supplying power to the gun, the spring preventing the tube and the line from becoming tangled and kinked during movement of the gun.
 References Cited UNITED STATES PATENTS 1' 3D IF 2,706,504 4/1955 144/32 scams rawmg gums US. Patent Oct. 7,1975 Sheet 1 of2 3,910,325
US. Patent 0a. 7,1975 Sheet 2 of2 3,910,325
AUTOMATIC FASTENER DRIVING MACHINE WITH HAND-HELD DRIVING GUN BACKGROUND OF THE INVENTION This invention relates to an automatic fastener driving machine and, more particularly, to a machine of the type which includes a hand-held driving gun adapted to be maneuvered horizontally to a preselected position over a workpiece and then shifted vertically to assemble a fastener with the workpiece. The gun includes a rotary motor which rotates a driver at high speeds in .the driving gun and which is connected to the gun by a flexible tube. At spaced intervals, a fastener from the feeding and delivery unit is blown through the tube by pressurized air and is loaded into the gun for subsequent driving into the workpiece. A power source is located adjacent the feeding and delivery unit and is connected to the gun by a flexible line which transmits power to the rotary motor of the gun.
SUMMARY OF THE INVENTION The general aim of the present invention is to provide a new and comparatively simple apparatus for suspending the driving gun for relatively free horizontal and vertical movement while also supporting and preventing tangling and kinking of the flexible delivery tube and power line, the foregoing being achieved without need of hanging the gun from an overhead ceiling supp A more detailed object is to provide a suspension and support apparatus in the form of a uniquely curved and pivotally mounted leaf spring which enables the driving gun to be shifted horizontally and then downwardly by the machine operator and which automaticallyreturns the gun upwardly when the operator removes downward pressure from the gun.
A further object is to provide a unique suspension spring which may be flexed to a high degree while still providing a good supporting platform for the flexible delivery tube and power line.
The invention also residesin the comparatively sim ple manner of supporting the driving gun for horizontal swinging and for horizontal adjustment.
These and other objects and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an automatic fastener driving machine equipped with a new and improved suspension apparatus incorporating the novel features of the present invention.
FIG. 2 is a side elevational view of the machine shown in FIG. 1.
FIG. 3 is a fragmentary elevational view of parts of the machine as seen from the right of FIG. 2, certain parts being broken away and shown in cross-section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustration, the invention is embodied in a machine for automatically driving threaded fasteners such as screws 10 into holes in a workpiece 11 which herein is held in a horizontal plane by a suitable fixture (not shown). The machine includes a driving tool or gun 13 which is adapted to be held in the hand of the machine operator and maneuvered horizontally to any selected position over the workpiece so as to aline the screw with a selected hole. Thereafter, the gun is manually moved downwardly to drive the screw and then is returned upwardly prior to being positioned over the next hole.
The screws 10 are delivered one at a time to the gun 13 by a feeding and delivery unit 14 which is disposed in a fixed location and which stores a large supply of screws. The gun l3 and the feeding and deliveryvunit 14 are disclosed fully in my aforementioned application and thus need not here be described in detail. It will suffice to say that the unit 14 includes a fixed support or housing 15 and that a flexible plastic line or tube 16 leads from the housing and extends to the gun 13. At spaced intervals, a screw from the supply is automatically placed in the tube and then is blown through the tube and to the gun by pressurized air which is introduced into the tube. Each screw delivered to the gun is driven into the workpiece 11 by an elongated screw driver bit (not visible) which is power-rotated by a rotary air motor 17. The latter is housed within the gun and is rotated by pressurized air delivered through a flexible line 19 connected to the upper end of the gun and extending to a pressure source 20 located adjacent the feeding and delivery unit.
In accordance with the present invention, the delivery tube 16 and the air line 19 are strung along a resiliently yieldable leaf spring 25 which not only prevents the'tube and the line from becoming kinked and tangled but which also suspends and supports the gun 13 in an upright position while still permitting horizontal and vertical movement of the gun. The spring is loaded when the operator pulls the gun downwardly to drive a screw 10 and thus the spring automatically returns the gun upwardly for horizontal re-positioning when the operator ceases to pull downwardly.
More specifically, the spring 25 is shaped generally as an inverted J and includes a substantially vertical lower section 26 (FIG. 2) which is located adjacent the housing 15 of the feeding and delivery unit 14. The spring further includes an arched upper section 27 defining a resiliently yieldable cantilever which overhangs the unit 14 and which curves upwardly, outwardly and then downwardly, the free end portion of the upper section being located in a generally vertical plane. The tube 16 and the line 19 are strung upwardly in side-byside relation along the rear side of the lower section, then follow the curvature of the upper side of the arched upper section and finally extend vertically downwardly from the free end portion of the arched section. Suitable clips 29 are snapped around the tube, the line and the spring at spaced locations along the spring in order to secure the tube and the line to the spring.
Advantageously, the spring 25 is defined by a resiliently yieldable spring metal strip 30 (FIG. 2) and by an overlying plastic strip 31 which is suitably secured to the rear and upper sides of the metal strip. The plastic strip 31 is made of a flexible but shape-retaining material such as nylon and has a uniform width of about 1% inches throughout its entire length. The metal strip 30, however, is generally triangular in shape and tapers continuously from a width of about 1% inches at point a (FIG. 2) to a width of only /8 inch at its extreme free end indicated at b. With the metal strip being triangular, virtually every fiber of the strip is flexed uniformly when the strip is deflected and, as a result, the strip is capable of being flexed one-third more than a compa rable strip of uniform width. In spite of the triangular shape of the metal strip 30, a wide supporting base or platform for the tube 16 and the line 19 is formed by the overlying plastic strip 31.
.As shown in FIGS. 2 and 3, the free end of the plastic strip 31 extends downwardly beyond the free end of the metal strip and is connected loosely by rings 33 to a shorter plastic strip 34, the rings 33 forming a horizontal hinge between the strips 31 and 34. The tube 16 and the line 19 are secured to the short strip 34 by an additional clip 29a, and the short strip is twisted through a ninety degree angle to change the plane through which the tube 16 and'line 19 extend. Thus, the tube and the line may be properly connected to the gun 13 when the latter is oriented as shown in FIG. 2. If it is desired-that the gun be turned ninety degrees about a vertical axis, a flat strip may be used in place of the twisted strip 34.
The gun 13 is suspended from the short strip 34 by a sling 35 formed by a slotted flexible strap which is looped around the gun and which is fastened at its upper ends to the lower end of the strip 34 by a clip 36. By virtue of the sling 35, very little force is applied to the tube 16 and the line 19 when the gun is pulled downwardly.
The lower section 26 of the spring 25 is supported for selective vertical adjustment and also for swinging about an upright axis. For this purpose, a C-shaped bracket 37 (FIG. 2) is attached to the forward side of the lower spring section 26 and is rotatably received on an upright post 39. The latter is attached to the housing 15 by upper and lower brackets 40 and extends upwardly along the forward side of the lower spring section. A collar 41 is telescoped over the post 39 and is located between the C-shaped bracket 37 and the upper bracket 40. By loosening a set screw 43, the collar 40 may be adjusted vertically along the post to change the elevation of the spring 25 and thus enable the gun 13 to be adjusted to a selected vertical position.
If the operator pulls sideways on the gun 13, the C- shaped bracket 37 will pivot freely on the post 39 to enable the spring 25 to swing horizontally and thus permit the operator to position the gun in the vicinity of the workpiece 11. When the gun is pulled forwardly or rearwardly, the strip 34 will hinge relative to the spring 25 as shown in phantom in FIG. 1 and enable the operator to position the gun over any one of the holes in the workpiece. After the gun has been so positioned, the operator may pull the gun downwardly to drive the screw 10. The arched upper spring section 27 deflects downwardly to permit downward movement of the gun and, as an incident thereto, is resiliently loaded so as to exert an upward bias on the gun. Accordingly, the spring automatically returns the gun upwardly when the operator stops pulling downwardly on the gun after driving the screw.
Means are provided to restrict bouncing of the spring 25 and also to enable the operator to adjust the preload on the spring. Herein, these means comprise a weight 45 which is adapted to be secured at various positions along a horizontal rod 46 by a set screw 47. The rear end of the rod is pivotally connected to the bracket 37 as indicated at 49 while the forward end of the rod is connected to the spring 25 by an upwardly extending flexible strap 50 which is looped through the free end portion of the plastic strip 31. When the operator releases the gun 13, the rod 46 and the strap 50 limit upward flexure of the spring 25 and help restrict bouncing of the spring. By adjusting the weight 46 along the rod 45, the operator may change the preload on the spring and thus adjust the liveliness of the spring.
From the foregoing, it will be apparent that the present invention brings to theart a new and improved suspension apparatus for a fastener-driving gun or the like. The spring 25 supports the gun for virtually universal movement and for automatic upward return while being far more convenient and versatile than a ceilingsupported suspension mechanism.
I claim as my invention:
1. An automatic fastener driving machine having a hand-held driving gun adapted to be moved horizontally to a preselected position and then shifted vertically to assemble a fastener with a workpiece, a feeding and delivery unit disposed in a fixed location and storing a supply of fasteners, a flexible tube extending between said feeding and delivery unit and said gun for carrying fasteners from said supply to said gun, a power source located adjacent said feeding and delivery unit, and a flexible line extending between said source and said gun for transmitting power from said source to said gun, the improvement in said machine comprising, means for supporting said tube and said line while suspending said gun for horizontal and vertical movement, said means including a resiliently yieldable leaf spring having a lower section extending upwardly from said feeding and delivery unit and having an upper section which arches upwardly, outwardly and then downwardly toward said gun, said tube and said line being strung along and supported by said spring, a pivot supporting the lower section of said spring for swinging about an upright axis to enable said gun to be swung horizontally, and the upper end section of said spring defining a vertically resilient cantilever and exerting an upward bias on said gun to enable the gun to be manually pulled downwardly and then automatically returned upwardly upon removal of the downward manual force.
2. A machine having a fixed support and having a hand-held tool, a flexible line extending between said support and said tool, and means for supporting said line while suspending said tool for up and down movement, said means comprising a resiliently yieldable leaf spring having a lower section extending upwardly from said support and having an upper section which arches upwardly, outwardly and then downwardly toward said tool, said line being strung along and supported by said spring, the upper section of said spring defining a vertically resilient cantilever and exerting an upward bias on said tool to enable the tool to be pulled manually downwardly and then automatically returned upwardly upon removal of the downward manual force.
3. A machine as defined in claim 2 in which said spring comprises a spring metal strip having an upper section which continuously decreases in width upon progressing outwardly, and a strip of substantially uniform width overlying said metal strip and supporting said line.
support for swinging about an upright axis and for selective vertical adjustment.
5. A machine as defined in claim 4 further including a hinge connecting said tool to the free end of the 4. A machine as defined in claim 2 further including 5 upper section of said spring.
means mounting the lower section of said spring on said