US3747828A

US3747828A - Fastener attaching machine

Info

Publication number: US3747828A
Application number: US00125753A
Authority: US
Inventors: D Dupee; W Hodgson
Original assignee: South Shore Machine Co Inc
Current assignee: South Shore Machine Co Inc
Priority date: 1971-03-18
Filing date: 1971-03-18
Publication date: 1973-07-24
Anticipated expiration: 1990-07-24

Abstract

An improved fastener attaching machine comprising a number of oppositely disposed jaw carriers having gravity and vacuum actuated fastener feed ducts leading from a central hopper for feeding fasteners and pre-positioning them for subsequent driving into opposed sides of an article disposed between the jaw carriers.

Description

Umted States Patent 1 91 1111 3,747,828

Dupee et al. 1 July 24, 1973 [54] FASTENER ATTACHING MACHINE 2,273,268 2/1942 Hunter et al 227/112 [75] Inventors: Donald E. Dupee; William S. da both of Hmaham, Mass- 3,023,412 3/1962 Watkins 221/152 x [73] Assignee: South Shore Machine Co., lnc.,

Bramtree1 Mass- Primary Examiner-Granville Y. Custer, Jr. [22] Filed: Mar. 1 1971 Attorney-Alfred H. Rosen et al.

[21] Appl. No.: 125,753

[57] ABSTRACT gill. An improved fastener attaching machine comprising a l 58] Field H 4 l l 5 number of oppositely disposed jaw carriers having 227/116 gravity and vacuum actuated fastener feed ducts leading from a central hopper for feeding fasteners and prepositioning them for subsequent driving into opposed [56] UNlTE S ::?rENTs sides of an article disposed between the jaw carriers. 3,581,967 6/1971 Benson 227/112 5 Clninis, 4 Drawing Figures PATENTEnJuLwm SHEU 1 BF 2 FIG.|

w INVENTORS we eg F IG.4 BY 6? ATTORNEY PAIimin mzmn SHEET 2 OF 2 w K W INVENTORS DONALD E. DUPEE BYWILLIAM S. HODGSON ATTORNEY FASTENER ATTACHING MACHINE This invention relates generally to improvements in fastener attaching machines and more particularly to fastener attaching machines, adapted to position and drive fasteners on opposed sides of a fixed object.

Fastener attaching machines, primarily pneumatically operated are commonly known in the industry and are generally utilized to position nails prior to driving with a machine actuated piston. In the past, nails have been driven on one side of an object and then by a manual or mechanical operation the object is reversed and the operation repeated. However, with the advent of multi-step assembly operations a need has developed for an improved fastener attachment machine, wherein an article, such as a paint brush may be positioned within the jaws of a nailing machine and one or more nails driven into opposed sides of the brush handle, securing the bristle container to the wooden han* dle. In such a manner, one complete step of the operation is eliminated with the resultant saving in manpower, time and an increase in efficiency.

Therefore, it is an object of this invention to provide a fastener attaching machine which will feed a plurality of fasteners to opposed sides of an article, simultaneously position the fasteners and drive them into opposite sides of the article. I

It is another object of this invention to provide a pneumatically operated feed mechanism to position fastening devices on opposed sides of an article, actuate a mechanism to drive one set of fasteners into one side of the object and drive other fasteners into the opposed side of the article.

It is a further object of this invention to provide a fastener attaching machine which will position and clamp an article to be fastened sequentially between the nailing jaws.

Other objects of this invention, will in part be obvious and will in part appear hereinafter.

Broadly stated, the basic feature of this invention is to provide a pneumatically powered transfer mechanism, operated by a vacuum system to position a number of fasteners on the under surface of an object with a gravity and/or vacuum system to feed andposition IN THE DRAWINGS FIG. 1 is a view in front elevation, illustrating the feed mechanism of the invention. 1

FIG. 2 is a view in front elevation, partly in section of machine with the feed mechanism shown in a cut-away position.

FIG. 3 is a view in elevation partly in section, of the jaw positioning and fastener holding mechanism.

FIG. 4 is a schematic of the lower driver operating mechanism.

Reference is now to be had to the drawings wherein an illustrative embodiment of the fastener attaching machine, a construction made in accordance with the present invention and designated by the reference numeral 10 is shown.

The basic frame of the machine as shown in FIG. 2, is of the conventional form having a yoke type frame 12 mounted on a supporting base 14 having a work table 16 positioned intermediate thereon. An upper jaw carrier 18 is mounted to an axially slideable guide 20 which is spring biased by means of a spring 22 away from the work table 16. A lower jaw carrier is axially adjustable on the lower guide 26 and operative off a main drive shaft 28 through suitable hydro mechanical linkage, as shown in FIG. 4. The main prime mover is an electric motor 34 (FIG. 1) which imparts motion to the main drive shaft 28 through a belt 36 and pulley 38. The main drive shaft carries

eccentrics

29 and 86, a cam 56, and a cam 40 which is in direct connection with the upper jaw carrier 18 via a projection 19 on the upper surface of the upper jawcarrier mount, guide 20.

An article clamping mechanism 42 comprises a laterally extending bar 44 having a resilient lower surface 46 mechanically connected to an internally spring loaded 48 piston 51 and fluid cylinder 50 actuated through suitable outside-furnished pressure via tubing 52 by means of a valve 54 adapted to be tripped by a cam 56 on the drive shaft 28.

The fastener feed assembly 58 illustrated in FIG. 1 is a simplified illustration representative of fastener feed devices that are available in the art, and comprises a hopper 60 having a plurality of individual races 62 with the forward ends 64 of them, respectively, having spring loaded fastener selector bars 66 actuated by a rocker arm 68 driven off the main shaft from the eccentric 29 via a link 69, in a manner that is known in theart. Each race 62 is individually connected to a fastener positioning tube 71 in the upper or

lower jaw carriers

18 or 70, respectively, by a conduit 72. The assembly comprising the upper jaw carrier 18, yoke frame 12, guide 20 and bias spring 22, as well as related drive mechanisms on the main drive shaft 28, will be recognized as a prior-existing product of the Assignee of this application, known as the Milliken Precision Nailing Machine. The fastener feed assembly 58 is also one of several available known forms of fastener feed assemblies which are sold with such machines. These assemblies, being prior-known commercial devices, are not illustrated in detail.

For purposes of illustration the lower jaw carrier 70 is shown in FIG. 3 with a fastener 74 in position in a fastener positioning tube 71 prior 'to actuation of the driver 76 therein. Fastener holding mechanisms or jaws .78 extends laterally across the upper surface of the jaw carrier 70 and are bifurcated by a slot, shown at 79 in FIG. 2, having a central aperture 80 in register with the output end of the positioning tube 71, and with a diameter less than that of the fastener shank 82. The fastener holding jaw mechanisms 78 are maintained in abutting relationship by means of spring members 84 (FIG. 2) positioned externally of the jaw carrier 70. (Similar jaws 78 and spring members 84 are found on the upper jaw carrier 18, and are, per se, known in the art.) Vacuum ports 87 connected via conduits 85 to a vacuum source (not shown) are utilized to maintain a pressure differential across the fastener in the jaw carrier 70 for positioning the fastener 74 in the positioning tube 71.

The fastener feed mechanism 58 is adapted by means of the tubing 72 so that fasteners 74 are dropped by gravity into the tubing leading to the upper jaw carrier 18 and positioned ready for driving by the respective drivers 76 (this much being known in the prior art), and the tubing 72 leading to the lower jaw carrier 70 is maintained under a vacuum applied at the output ends so that fasteners dropped thereon at the feeder ends are positioned by a vacuum system via conduits 85 energized without interruption from an external source (not shown), in the proper position prior to actuation of the drivers 76, as is apparent in FIG. 3.

The lower drivers 76 are actuated by means of an eccentric 86, shown in FIG. 4, which is secured to the drive shaft 28 and is operative through an eccentric strap 88 to create pressure in a master hydraulic cylinder 90 which pressure is applied through tubing 92 to a slave hydraulic cylinder 94 having a piston shaft 95 which is normally spring biased away from the work table 16 by spring 96 as is shown in FIG. 1. The lower drivers 76 are connected to a cross-arm 77 which in turn is connected to the outer end of the shaft 95. It will be appreciated that the hydraulic system shown in FIG. 4 is exemplary only.

OPERATION An article to be fastened is presented to the machine as shown in the dotted outline in FIG. 2 and for purposes of illustration is depicted as a paint brush 97 in such a manner that its full insertion on the work table manually actuates a switch 98. The sole purpose of the switch is to trip a clutch (not shown) causing the motor 34 through said clutch to rotate the shaft 28 one revolution and thereby allow the machine to make a single cycle. As the main drive shaft 28 rotates the cam 56 (FIG. 2) at a point in the machine cycle of approximately past top dead center opens valve 54 allowing fluid pressure to be exerted on the piston 51 in the fluid cylinder 50 overcoming the force of the spring 48 causing the bar 44 to clamp the article onto the upper surface of the work table 16. As the drive shaft continues to rotate after a predetermined arc the valve 54 closes and fluid is bled from the fluid cylinder 50 and the spring biasing action allows the bar to release the article.

During this primary operation the rocker arm 68 operative off the main shaft eccentric 29 laterally moves the selector bars 66 allowing one fastener to be dropped into each of the conduits 72 leading to the

jaw carriers

18 and 70. Simultaneously the hopper 60 is tilted upward by the link 61 coupled to the pulley 38 so that fasteners 74 will be urged toward the conduits 72. The fasteners in the conduits leading to the upper jaw carriers 18 fall by means of gravity and the fasteners in the conduits leading to the lower jaw carriers 70 fall by gravity until they come under the influence of the vacuum system connected via conduits 85.

The rotation of the drive shaft 28 causes the upper jaw carrier 18 to reciprocate in the prior known usual manner, simultaneously causing the drivers 76 therein to drive the upper fasteners by rotating the crank stud 31. The lower drivers 76 are actuated by the eccentric 86 to pressurize the closed hydraulic link comprised of the master cylinder 90, tubing 92 and slave cylinder 94 to overcome the biasing action of the spring 96 to force the lower drivers to reciprocate. The lower jaw carrier and guide 26 are relatively fixed and adjustable on the guide 24 for varying thickness of the article. The force of the drivers 76 in the lower jaw carrier 70 against the fasteners 74 therein forces the fasteners upward, pivoting the jaws of the nail holding mechanism 78 outwardly overcoming the holding action of the spring member 84 and allowing the drivers to drive the fasteners into the article. Since the upperjaw carrier 18 is spring loaded away from the work table 16 by the bias spring 22, after the fasteners are driven into the article the upper jaw carrier returns to its open position away from the work table 16, while the lower jaw carrier 70 remains in its predetermined fixed position.

While there have been described herein what are at present considered preferred embodiments of the invention, it will be obvious to those skilled in the art, that modifications and changes may be made without departing from the essence of the invention. It is therefore to be understood that the exemplary are illustrative and not restrictive of the invention, the scope of which is defined in the appended claims and that all modifications that come within the meaning and range of equivalency of the claims are intended to be included herein.

We claim:

1. A fastener attaching machine comprising:

a. a frame supporting upper and lower jaw carriers in vertical alignment and oppositely spaced from each other, each jaw carrier having at least one jaw mechanism for holding a fastener in position for placement in a workpiece,

b. means for moving at least one of said jaw carriers into engagement with an article disposed therebetween,

0. a fastener reservoir and conduit means connected from said reservoir to each of said jaw carriers for bringing fasteners to said jaw mechanisms, said conduit means being at all times open at their respective ends adajcent said reservoir,

d. said conduit means connected to said upper jaw carrier being arranged for conveying fasteners to the upper jaw carrier by means of gravity, and

e. pneumatic means coupled to said conduit means connected to said lower jaw carrier for delivering and positioning fasteners in the lower jaw carrier, said pneumatic means providing a less than atmospheric continuous pressure in the portion of said conduit means adjacent the jaw mechanism and before the fastener therein thus attaining a continuous pressure gradient across said fastener for imparting continuous motion to said fastener through said conduit from the reservoir end thereof to said jaw mechanism, and

f. driving members cooperating with each of said jaw carriers for driving fasteners into an article held between said jaw carriers.

2. A fastener attaching machine as set forth in claim 1, wherein the pneumatic means for delivering and positioning fasteners to the lower jaw carriers comprise port means in the lower jaw carrier in connection with the end of said conduit means connected to said lower jaw carrier, and further conduit means for coupling said port means to a source of vacuum.

3. A fastener attaching machine comprising, a source of fasteners, a frame having a work table disposed thereon, an upper jaw carrier axially movable on said frame toward the work table, a lower jaw carrier positioned on said frame in opposed alignment with said upper jaw carrier relative to said work table, so that an article located on said work table will be between said jaw carriers, means for moving said upper jaw carrier into abutting relation with an article on said work table, fastener conduits running from said source to each of said jaw carriers, said conduits having continuously open input ends for receiving fasteners from said source, mechanical means for actuating drivers within said jaw carriers, and continuously-applied vacuum means for delivering fasteners to at least the lower jaw carrier.

4. A fastener attaching machine comprising,

a. a prime mover,

b. a frame having a work table disposed thereon,

c. an upper jaw carrier axially moveable toward said work table, d. fasteners adapted for gravity feed to said upper jaw carrier,

e. a lower jaw carrier positioned in axial relationship with said upper jaw carrier,

f. continually operable pneumatic means for delivering fasteners to said lower jaw carrier,

g. means for retaining a work object in position between said jaw carriers,

h. driving members cooperating with each of said jaw carriers, whereby actuation of said driver members will drive fasteners into opposed sides of said work object.

5. A fastener attaching machine as set forth in claim 4 wherein said means for retaining a work object between said jaw carriers comprise, a laterally extending bar positioned over said work table and being connected to a fluid cylinder, valve means operative by a cam off said prime mover to pressurize said cylinder in a time sequence prior to actuation of said driving members, for moving said bar toward said work table to hold an article on said work table.

Claims

1. A fastener attaching machine comprising: a. a frame supporting upper and lower jaw carriers in vertical alignment and oppositely spaced from each other, each jaw carrier having at least one jaw mechanism for holding a fastener in position for placement in a workpiece, b. means for moving at least one of said jaw carriers into engagement with an article disposed therebetween, c. a fastener reservoir and conduit means connected from said reservoir to each of said jaw carriers for bringing fasteners to said jaw mechanisms, said conduit means being at all times open at their respective ends adajcent said reservoir, d. said conduit means connected to said upper jaw carrier being arranged for conveying fasteners to the upper jaw carrier by means of gravity, and e. pneumatic means coupled to said conduit means connected to said lower jaw carrier for delivering and positioning fasteners in the lower jaw carrier, said pneumatic means providing a less than atmospheric continuous pressure in the portion of said conduit means adjacent the jaw mechanism and before the fastener therein thus attaining a continuous pressure gradient across said fastener for imparting continuous motion to said fastener through said conduit from the reservoir end thereof to said jaw mechanism, and f. driving members cooperating with each of said jaw carriers for driving fasteners into an article held between said jaw carriers.

4. A fastener attaching machine comprising, a. a prime mover, b. a frame having a work table disposed thereon, c. an upper jaw carrier axially moveable toward said work table, d. fasteners adapted for gravity feed to said upper jaw carrier, e. a lower jaw carrier positioned in axial relationship with said upper jaw carrier, f. continually operable pneumatic means for delivering fasteners to said lower jaw carrier, g. means for retaining a work object in position between said jaw carriers, h. driving members cooperating with each of said jaw carriers, whereby actuation of said driver members will drive fasteners into opposed sides of said work object.