US3063421A

US3063421A - Fastener applying implements

Info

Publication number: US3063421A
Application number: US99186A
Authority: US
Inventors: Edward I Fisher
Original assignee: Bostitch Inc
Current assignee: Bostitch Inc
Priority date: 1960-03-22
Filing date: 1961-03-29
Publication date: 1962-11-13
Anticipated expiration: 1979-11-13
Also published as: GB915858A; DE1478800A1

Description

Nov. 13, 1962 E. 1. FISHER 3,

FASTENER APPLYING IMPLEMENTS Original Filed March 22, 1960 2 Sheets-Sheet 1 INVENTOR. L EdzdMZJZZ-sfiar '0 T BY ATTORNEYS Nov. 13, 1962 E. 1. FISHER FASTENER APPLYING IMPLEMENTS 2 Sheets-Sheet 2 Original Filed March 22, 1960 INVENTOR. Bylzzhz-JZW ATTORNEYS I United States Patent Ofilice 3,%3,4Zl Patented Nov. 13, 1962 3 Claims. (Cl. 121-3) This application is a division of my prior application Serial No. 16,702 filed March 22, 1960, for Improvements in Piston-Actuated Fastener Applying Machines and Implements.

The present application relates to adjustable connecting means between the piston and fastener-driver for altering their relationship to vary the effective length of the driver for driving fasteners of different lengths. In most machines ofthe prior art it is necessary to open the casing of the machine to gain access to the means for adjusting the relationship between the driver and piston to render it capable of driving fasteners of different lengths.

One object of the present improvement is to provide adjustable connecting means between the piston and driver accessible from the outside of the machine so that the necessary adjustment may be accomplished without opening the casing of the machine or disassembling any parts of its mechanism.

Another object is to provide adjustable connecting means between the piston and driver conveniently accessible from the outside of the machine without removing a cap, cover or other closure member or disassembling any of the parts of the machine.

Another object is to provide an improved construction of screw-threaded connecting means between the piston and driver which is accessible from the outside of the casing to effect relative displacement between said elements for adjusting the extent of stroke of the driver.

Another object is to provide an improved construction of the adjustable connecting means which requires relatively few elements of simple construction applied to the driving means of the machine.

While the invention is herein disclosed as applied to use with a power-driven stapling machine, it is to be understood that the present improvements may be adapted for use with manually-operated stapling appliances. As shown in my prior application from which the present application is divided, the present invention is applied to a stapling machine driven by pressure fluid as described briefly herein; reference being had to the prior pending application for a more detailed description of the complete machine.

Further objects and advantages of the present improvement are set forth in the following specification, or will be obvious to those skilled in the art; it being understood that the present disclosure is by way of example only to illustrate a preferred embodiment of the invention as shown by the accompanying drawings. In the drawings:

FIG. 1 is a side 'elevational view of the complete implement, part-sectional in a plane intersecting the vertical axis of the machine and showing the driving piston as raised to its uppermost position;

FIG. 2 is a similar sectional view of the fore part of the implement showing the piston depressed and the driver at the end of its stroke with the trigger-operated valve open for exhausting pressure from the bottom of the cylinder;

R6. 3 is a transverse sectional plan view on line 33 of FIG. 1 illustrating the detent-means for locking the adjusting means in fixed relationship;

FiG. 4 is a transverse sectional plan view on line 4-4 of FIG. 1 with the locking means for the adjusting means illustrated in detail; and

FiG. 5 is a bottom plan view of the base of the machine head on line 5-5 of FIG. 1 showing the gland through which the driver-blade slides.

While the present invention is herein illustrated and described as applied to use in a portable, pneumaticallyoperated machine, it is to be understood that it may be embodied in other, structures such as avmanually-operable implement in which the driver-blade is connected to a slidable plunger; or a stationary machine mounted on a suitable base or standard. The present implement may be employed in many different industries, for example: to drive fasteners for attaching the parts of automobile bodies; for fastening covers to boxes and cartons; tacking or nailing sheathing and roofing to buildings; and for fastening together numerous other articles and objects.

As herein illustrated, the implement is generally of conventional design comprising a casing A embodying a head H containing the operating mechanism and surmounting the forward end of a magazine M of usual construction for supplying inverted U-shaped fasteners such as wire staples S. The forward end of the magazine M may be connected to the base of the head H by any suitable means, being shown as constructed with a nosepiece N having a slotted raceway or guideway 11 in which the staple-driver D reciprocates. The nosepiece N may be formed with a bifurcated bracket T having lateral flanges F at the top abutting a closure plate P fastened to the base of the head H of the casing A. The head H is initially left open at the bottom for assembling the operating mechanism of the machine therein and the plate P may be fastened to its base by screws 1 (FIGS. 1, 2). The magazine M extends rearwardly from the nosepiece N and may be of U-shape in crosssection formed of sheet-metal folded to provide a hollow structure. Fastened within the magazine M is a longitudinally-extending core or rail C on which the staples S are mounted to slide forward for feeding the foremost staple of the series into the guideway n through which the staple-driver D slides. A staple-pusher I of usual construction is slidably mounted on the core C to be urged forward by a suitable spring (not herein shown) for advancing the staples to deliver them singly to the driving means; these last-named elements of the machine not being described in detail herein as they form no part of the present invention.

The main casing A of the machine may be constructed as a casting comprising the hollow head H containing an integrally cast cylinder 2 having an open top. The upper portion of the head H forms a generally flaring interior chamber 3 constituted as a reservoir for pressure fluid. The walls of the chamber 3 in the head H are continued rearwardly in the form of a hollow handle 4 at? by which the implement may be grasped for transporting it and holding its nose N against the work. Compressed air or other pressure fluid may be supplied to the reservoir 3 in the head H by connecting the end of the handle 4 to a hose 12 leading from a suitable source thereof. The interior of the handle 4 opens into the pressure chamber 3 in the head H through an orifice 5 of relatively large area so that constant pressure may be maintained within said chamber.

The upper open end of the cylinder 2 is flanged inwardly at 8 and formed with an interior groove 3 in which is mounted a sealing gasket 10. The cylindrical piston 7 is of hollow construction, open at the top and closed at the bottom by a relatively thick wall 11. The bottom wall 11 of the piston 7 is shouldered on the outside at 12 to project outwardly for increasing its lower area and thus provide a differential relationship with the area on its upper surface. A groove 13 formed in the periphery of the projecting portion 12 of the wall 11 has a flexible gasket 14 held therein. A second gasket 15 mounted above the projecting rim 12 at the bottom of the piston 7 seats against the shoulder of the enlargement so that both gaskets are in sliding contact with the inner wall of the cylinder 2 to form a seal between the piston and cylinder.

For diflerent kinds of work requiring staples of greater or lesser length it has usually been the practice to adjust the connection between the driver blade and piston for changing their relationship so as to regulate the extent of the driving stroke of the driver for inserting staples of certain length to the proper depth in the work. It will be obvious that for driving relatively large staples with long legs the stroke of the driver must be continued to an extent equal to or even slightly greater than the length of the staple legs. Consequently, the driver must be ad justed to project below the piston in proportion to the maximum extent required. On the other hand, for shorter staples the extent of projection of the driver below the piston is reduced by adjusting the driver in its connection to the piston dependent upon the type of work and the size of the staples being used. In practically all machines now in use adjustment of the connection between the staple-driver and piston to regulate the eflective length of the driver has only been possible by opening the casing of the machine and disassembling parts of its driving means. In the present improved construction, however, the head of the machine may be closed after the operating parts have been assembled therein and means conveniently accessible from the outside of the machine provide for adjusting the driver-blade vertically in relation to the piston without opening the casing. The novel and ingenious means for eflecting this advantageous result are constructed and arranged as next described:

The staple-driver D is in the form of a flat metal blade provided at the top with a transverse enlargement or cylindrical bead 16 engageable in a drilled hole 17 diametrically bisecting a screw-threaded plug or stud 20. The stud 20 is screwed into a bore 21 in the bottom wall 11 of the piston 7 with the flat portion of the driver engaging in a slot 22 below the hole 17. By the present improved construction relative turning motion between the piston 7 and the stud 20 will effect micrometer adjustment of the driver-blade D by small increments or decrements to lower or raise its driving end in relation to the piston.

The threated stud 20 is formed with a disk-like head 23 connected to its upper portion by a square neck 24 (FIGS. 1, 4). The neck 24 of the plug 20 provides means cooperating with a hairpin-shaped pawl 25 arranged with its legs resiliently engaging opposite flat sides of the neck to act as detent-means for preventing unwarranted rotary movement of the piston 7 with respect to the driver-blade D. A relatively long pin 26 held in a drilled hole in the bottom wall 11 of the piston 7 projects upwardly therefrom between the legs of the pawl 25 to adapt it to engage therewith for limiting the turning of the piston in the bore of the cylinder 2.

For rotating the piston 7 about its axis in the cylinder 2 to adjust the vertical extent of projection of the driver D relatively thereto, manually-operable means may be provided available above the top of the head H. As herein illustrated one form of such adjusting means may consist in a knurled knob or disk 30 adapted to be gripped in the fingers and engaged with the piston 7 for turning it. As herein shown a stud 32 projects from the under side of the disk 30 by which it is rotatively mounted in a bore 33 in the top of the head H. The stud 32 may be secured to the finger-grip or disk 30 by its reduced knurled end 33' (FIG. I) forced into a bore therein. Held in a slot in the periphery of the stud 32 is a flexible gasket 34 engaging the interior of the bore 33 for sealing the joint therebetween. The lower end of the stud 32 is formed with a disk-like head 35 engaging in a finished recess 36 on the under side of the top wall of the head H.

A thin metal strip or bar 37 is held in a transverse slot on the'under side of the head 35 with its ends projecting radially therefrom to provide a key-like wrench for engagement with the piston 7. The projecting ends of the bar 37 are adapted to engage in pairs of diametrically opposed slots 40-40 and 4141 (FIG. 3) in the upper rim of the piston 7 to provide for turning the latter about the screw-threaded stud 20 to adjust the vertical relationship between the driver D and the piston; that is, for either increasing or decreasing the extent of projection of the driver and the position of its lower driving edge below the piston. It is obvious that the driver-blade D will be prevented from turning when the piston 7 is rotated due to its engagement with the sides of the throat n in the nosepiece N.

To relieve shock and jar on the piston 7 as it descends in a driving stroke a resilient washer or bumper is disposed in the bottom of the cylinder 2 seated on the closure plate P. The bumper 50 may be constructed of rubber or other suitable resilient material with a central slotted opening 52 in alinement with a slot 53 in the plate P through which the driver slides. The opening 52 at the center of the bumper 50 is enlarged at the top and formed with a relatively deep lip 55 (FIGS. 1, 5) surrounding the driver-blade D and having its marginal edge impinging resiliently thereagainst to provide a leak-proof g and.

The operation of the above described means for adjusting the connection between the driver blade D and the piston 7 is explained as follows: Assuming the piston 7 to be at the upper end of its stroke as shown in FIG. 1, the finger-knob or disk 30 will normally be raised with its key or wrench bar 37 above the slots 40 and 41 in the upper end of the piston. By simply pressing the disk 30 downward the ends of its key 37 may be engaged with either pair of slots 40-40 and 41-41 in the upper rim of the piston 7; it being observed by reference to FIG. 3 that said slots are of somewhat greater extent than the width of the key 37 to render it convenient for engaging the key therein. For example, even though neither pair of slots may be in alinement with the ends of the key 37, a slight turning movement of the finger-knob 30 will locate the key for engagement with one pair of slots as it is pressed downwardly by the operator. After the key 37 has been entered in the slots 4040 or 41-41, as the case may be, the piston 7 may be rotated by the knob 30, either clockwise or counter-clockwise, to a suflicient extent to eifect the desired adjustment for raising or lowering the driver-blade D with respect to the piston 7. As the piston 7 is rotated the pin 26 in its interior will engage one or the other of the legs of the pawl 25 to swing the latter around until its legs come into engagement with certain of the opposite sides of the square neck 24 of the stud 20. With the adjustment completed the pawl 25 will act as detent-means to prevent unwarranted turning of the piston 7 in the cylinder 2; although a limited amount of rotative motion of the piston may be permitted during its reciprocation as usually considered desirable to prevent undue wear.

It will be understood that the piston 7 may be rotated through an arc of from 90 to 360, or even throughout several turns to effect the desired extent of relative vertical adjustment between it and the driver-blade D. In any case, the preferred practice is to rotate the piston until the opposite legs of the pawl 25 snap into engagement with certain of the opposed flat sides of the neck 24 on the stud to prevent it from further unwarranted turning. Even though such engagement is not completed the detent-means still will act to prevent excessive rotative movement of the piston with respect to the threaded stud 20 which connects it with the driver-blade D. Through this construction and arrangement of the present improved micrometer adjusting means, the relationship between the driver-blade D and piston 7 can be regulated with extreme accuracy without opening the head H or disassembling any parts of the machine.

The method of operation of the complete machine is explained in full in my previous application from which the present case is divided. It is to be noted, however, that the instant invention of means for conveniently adjusting the relationship between the driving piston and fastener driver-blade increases the utility or versatility of the machine by adapting it for driving fasteners of different lengths. It is to be understood that the stroke of the piston 7 is of constant length at all times but to adapt it to drive fasteners of relatively large size, such as staples with legs of maximum length, the driver must be of sufficient extension to insert the staples to the required depth. Usually, machines of the present type are constructed to provide a piston stroke of a length at least equal to, or slightly greater than, the length of the longest staples. In machines of the prior art, however, it has been necessary to open the casing of the machine to adjust the parts of the driving mechanism for driving staples of greater or lesser length. For this purpose either a different length of driver is necessary or the relationship between the driver and piston required adjustment.

In the present machine the stroke of the piston 7 is of such extent that normally with the piston in its uppermost relationship as shown in FIG. 1 its lower driving edge is raised somewhat above the staple S to be operated on even though staples of substantially maximum length are being used. Consequently if shorter staples are to be used it is only necessary to adjust the driver D upwardly in relation to the piston 7 in the manner as hereinbefore explained; that is by rotating the piston about the stud 20. In this way the relative extension of the driver can be regulated with micrometer accuracy by turning the finger-grip or knob 30 without opening the casing of the machine or disassembling any of the parts. In fine, the present improvement provides manually operable means readily accessible from the outside of the casing and available at all times for adjusting the amount of extension of the driver below the piston without delays for opening the casing or disassembling any of the parts.

While the present improvements are shown and described as embodied in a preferred form of construction, it is to be understood that various modifications may be made therein without departing from the spirit or scope of the invention as set forth in the accompanying claims. Therefore, without limiting myself in this respect, I claim:

1. In a machine of the type indicated, a casing having a head with a cylinder therein, a piston reciprocable in said cylinder, a driver-blade slidable in a guideway in said head to prevent it from turning therein, screwthreaded means connecting said driver-blade with said piston, and means engageable with the top of said piston to effect relative rotative movement between said piston and said screw-threaded means for adjusting the effective length of said driver-blade below said piston, said means engageable with said piston being manually operable from above the top of said head.

2. In a fastener applying machine, a casing having a head, a pressure chamber in the upper part of said head, a cylinder located below said pressure chamber and open at the top for communication therewith, a piston reciprocable in said cylinder, a driver fo reciprocation by said piston, screw-threaded means connected to said driver and engaging a threaded bore in said piston, and rotatable means at the top of the head manually operable for effecting relative displacement between said piston and said threaded stud to effect longitudinal adjustment of said driver axially of said piston.

3. In a fastener applying machine, a casing having a hollow head with a pressure chamber therein, -a cylinder in said head, a piston slid-able in said cylinder, a threaded stud screwed into the bottom of said piston, a driver fixedly connected to said stud to project downwardly therefrom, manually-operable means rotatable above the top of said head, and a member carried by said lastnamed means for engaging slots in the upper end of said piston for rotating it about said threaded stud to raise or lower the driver in relation thereto for adjusting the extent of its driving stroke 4. In a fastener applying implement, a casing having a head with a closed top, a reservoir for pressure fluid in said head, a cylinder in said head in communication with said pressure fluid reservoir, 2. piston slidably in said cylinder, a threaded stud screwed into said piston, a driver fixedly connected to said stud to'project downwardly from said piston, yieldable detent means for normally preventing said piston from turning relatively to said stud, a finger knob rotatably mounted in the top of said head, and means carried by said knob for engaging said piston to effect relative rotation between it and said stud to adjust the extent of driving stroke of said driver.

5. In a fastener applying machine, a casing having a head closed at the top and open at the bottom for insertion of the operating mechanism thereinto, a closure for the bottom of said head, a cylinder in said head, a fluid pressure reservoir above said cylinder, a piston reciprocable in said cylinder, a driver reciprocable by said piston, screw-threaded means connecting said driver to said piston, and manually-operable means accessible above the top of the head and provided with means within the head for relatively rotating said piston and said screw-threaded means to adjust said driver and vary the extent of its driving stroke.

6. In a fastener applying implement, a casing formed with a hollow head closed at the top and provided with a reservoir therein for pressure fluid, a cylinder in the lower part of said head with its upper end in communication with said pressure reservoir, a hollow piston in said cylinder open at the top and closed by a bottom wall, a threaded stud screwed into the bottom wall of said piston, a driver-blade fastened to 'said stud, said stud having a flat-sided portion, a resilient pawl engageable with the flat sides of said stud, means engageable with said pawl fo normally preventing rotation of said piston about said threaded stud, a finger-knob mounted above the closed top of said head by a stern rotatable in a bore therein, and means carried at the lower end of said stem engageable with means on the piston for turning it relatively to said stud whereby to adjust said driver-blade vertically to extend or reduce its length below said piston.

7. In a machine of the type indicated, a casing having a head with a cylinder therein, a piston reciprocable in said cylinder, a driver-blade slidable in a guideway in said head, screw-threaded means connecting said driver-blade with said piston, means for preventing rotative movement of said screw-threaded means relative to said piston, means engageable with the top of the piston for rotating it relative to said screw-threaded means for adjusting the effective length of said driver-blade below said piston, and

7 means accessible from above the top of the head for manually rotating said piston engageable means.

8. In a machine for driving fasteners, a casing, a cylinder in said casing, a piston reciprocable in said cylinder, means for reciprocating said piston, -a driver for applying fasteners to a workpiece, screw-threaded means connecting said driver with said piston for reciprocation thereby, means for positively preventing rotation of said screw-threaded means, resiliently operated mean for normally preventing rotation of said piston relative to said screw threaded means, means in the casing for engaging the top of the piston to rotate it relative to said References Cited in the file of this patent UNITED STATES PATENTS 2,703,557 Polki Mar. 8, 1955 2,729,198 Faccou Jan. 3, 1956 2,774,968 Osborne et al Dec. 25, 1956 2,881,738 Baker Apr, 14, 1959