US2994880A

US2994880A - Upholsterer's pneumatic tack driving hammer

Info

Publication number: US2994880A
Application number: US21022A
Authority: US
Inventors: Willis Clyde Pharis
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-04-08
Filing date: 1960-04-08
Publication date: 1961-08-08
Anticipated expiration: 1978-08-08

Description

Aug. 8, 1961 c. P. WILLIS UPHOLSTERERS PNEUMATIC TACK DRIVING HAMMER Filed'April 8, 1960 4 Sheets-Sheet 1 INVENTOR ATTORNEYS Aug. 8, 1961 c. P. WILLIS UPI-IOLSTERERS PNEUMATIC TACK DRIVING HAMMER Filed April 8, 1960 4 Sheets-Sheet 3 61/? WILL/5 INVENTOR ATTORNEYS Aug. 8, 1961 c. P. WILLIS UPI-IOLSTERERS PNEUMATIC TACK DRIVING HAMMER Filed April 8, 1.960

4 Sheets-Sheet 4 61/ WILL/5 INVENTOR ATTORNEYS United States Patent 2,994,880 UPHOLSTERERS TACK DRIVING HAMMER Clyde Pharis Willis, Conover, N.C. Filed Apr. 8, 1960, Ser. No. 21,022 Claims. (Cl. 144.4)

This invention relates to tools, of the pneumatic driving type used by upholsterers.

The primary object of the invention is to provide a power hammer which will successively feed tacks from a magazine into the path of travel of a pneumatically operated hammer in the form of a plunger rod, which positions the tacks upon contact therewith.

An important object of the invention is to provide a pneumatic hammer of this character which may be held at a particular location to drive a tack through the medium of a pneumatically operated hammer rod controlled by the movement of a trigger, thereby insuring the proper positioning of the tacks passing through the driving end of the tool.

A further object of the invention is to provide a tool of this character which is supplied with a handle of pistol like form so that the tool may be conveniently handled and manipulated with the minimum amount of effort on the part of the operator.

A still further object of the invention is to provide a pneumatically operated hammer wherein the hammer rod will be moved to the rear end of the body of the hammer compressing a coiled spring held therein, means being provided for automatically releasing the hammer rod to the action of the coiled spring, to suddenly urge the hammer rod forwardly into contact with a tack delivered in the path of travel of said hammer rod, positioning the tack.

Still another object of the invention is to provide means for adjusting the tension of the spring to regulate the power and stroke of the hammer rod, thereby adapting the tool for a particular use. 7 I

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combination of parts, hereinafter more fully described and pointed out in the claims, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawings:

FIGURE 1 is an elevational view of a pneumatically operated tack driving hammer, constructed in accordance with the invention.

FIGURE 2 is a longitudinal sectional View through the major portion of the tool.

FIGURE 2* is a fragmental sectional view of the rear end of said tool.

FIGURE 2 is a fragmental sectional view through the driving end of the tool.

FIGURE 3 is a plan view of the driving end of the tool, the tack chute being shown in section.

' FIGURE 4 is a sectional View taken on line 4-4 of FIGS. 1 and 3.

FIGURE 5 is a sectional view taken on line 5-5 of FIGS. 1 and 3.

FIGURE 6 is a sectional view taken on line 66 of FIGURE 3.

' FIGURE 7 is a. sectional view taken on line 7-7 of FIG. 2.

FIGURE 8 is a sectional view taken on line 8'8 of FIG. 2*-

FIGURE 9 is a fragmental longitudinal sectional view through the hammer rod setting sleeve.

Patented Aug. 8, 1961 FIGURE 10 is a side elevational view of said hammer rod setting sleeve.

FIGURE 11 is a sectional view taken on line 1111 of FIG. 10.

FIGURE 12 is a transverse sectional view taken on line 12-12 of FIG. 2.

FIGURE 13 is a bottom view showing the manner of mounting the tack magazine.

Referring to the drawings in detail, the tool comprises a cylindrical body portion indicated generally by the reference character 5, the body portion 5 having its for- Ward end threaded at 6 to secure the head 7 of the tool, which is internally threaded and fitted over the threaded end of the body portion 5, as shown by FIG. 2 of the drawings.

This head 7 is formed with a bore 8 extending longitudinally through the axis thereof, one end of the bore being enlarged and threaded at 9 to receive one end of the hammer rod barrel 10, the hammer rod barrel being of a length to extend to a point adjacent to the rear end of the body portion 5 where it is closed by means of the cap 11.

The rear end of the body portion 5 is closed by means of the threaded cap 12 and the cap is provided with a recess 13 in which one end of the coiled spring 14- rests. The coiled spring 14 is substantially large and encircles the hammer rod barrel 10, with one end thereof engaging one end of the cam sleeve 15, which is slidably mounted on the hammer rod barrel, as clearly shown by FIG. 2 of the drawings. This cam sleeve 15 is extern-ally threaded throughout the major portion Of its length and is provided with an annular flange 16 extended outwardly .therefrom. This flange 16 provides a stop for the cup washer 17, which is held in place on the cam sleeve 15, by means of the nut 18. The cam sleeve- IS-being of a diameter appreciably less than the interior diameter of the body portion 5 provides a chamber 19 between the cam sleeve and body portion 5, to receive air under pressure for moving the cam sleeve longitudinally of the hammer rod barrel, in one direction.

The cam sleeve 15 is formed with openings in which the cams 20 are slidably mounted, the cams 20 being normally urged inwardly by means of the spring member 21 that is secured to the outer surface of the cam sleeve 15 by a screw 22, as shown by FIGURE 11, the ends of the spring 21 resting against the outer ends of the cams 20.

These cams 20 move through slots 23 formed in the wall of the hammer rod barrel and are disposed diametrically opposite to each other. The rear ends of the slots 23 are inclined at 24 providing cam surfaces whichlie in the path of travel of the cams 20 when the cam sleeve 15 moves to its limit at the rear end of the hammer rod barrel, so that as the cams ride over the inclined or beveled edges 24, the cams 20 will be moved outwardly for purposes to be hereinafter more fully described. A stop ring indicated at 25 is threaded on the rear end of the hammer rod barrel 10 and is held in place by set screw 26, to the end that the stop ring may be adjusted to various positions to regulate the rearward movement of the cam sleeve 15.

The hammer rod, which is indicated by the reference character '27, is slidably mounted within the hammer rod barrel 10 and is urged towards the forward end of the tool, by means of a coiled spring 28, mounted within the hammer rod barrel, one end of the coiled spring engag-- ing the rear end of the enlargement 29 formed on the inner end of the hammer rod, while the opposite end of said coiled spring 28 rests against the threaded cap 11, as shown by FIG. 2. Due to this construction, it

, be seen that the tension of the coiled spring 28 may be regulated to project the hammer rod with various grees of force to meet the requirements of use.

As shown by FIG. 2 of the drawings, the forward end of the enlargement '29 is formed with a shoulder 30 with which the cams 20 engage so that upon movement of the cam sleeve 15 towards the rear end of the-tool, the hammer rod is moved therewith, the hammer rod being released as the earns 20 move outwardly over the inclined or beveled edges 24 of the slots 23. The hammer rod is then projected forwardly by the action of the coiled spring 28. p

-. Formed on the hammer rod 27 and disposed in spaced relation with the shoulder 30, is an annular shoulder 31, which shoulder 31 is designed to contact the shoulder 32 formed in the surface of the bore ,8, as better-shown by FIG. 2 of the drawings. This shoulder 31 is so arranged that when the hammer rod 27 moves to the limit a,994,ssq

of its forward movement in setting a tack, the hammer rod 27 will be in a position so that the earns may engage the shoulder 30 for the return movement of the hammer rod 27, with the sleeve 15. The head 7 is formed with elongated cut out portions 33 arranged on opposite sides thereq Within which the spring fingers 34 are arranged, the spring fingers 34 having their forward ends extending laterally as at 35, where they lie in the path of travel of tacks delivered thereto from the magazine 36, which is fed with tacks that are positioned in the chute 37. The magazine 36 is formed with a slot 38 that extends therethrough, the lower portion ,of the slot accommodating a pivoted arm 39 that has its; forward end curved as at 40, the curved end being of a length to extend through the slot, the curved upper surface of the pivoted arm providing a support for the lowermost tack .41 in the vertical line of tacks held within-the magazine 36, as better shown by FIG. 2 of the drawings.

The pivoted arm 39 is formed with a pair of inclined slots 42 arranged in vertical spaced relation with respect to each other, the slots 42 being provided for the reception of the pivot pins 43 that are secured to the rear of the magazine 36. Thus it willbe seen that upward movement of the pivoted arm 39 will cause an inward swinging movement of the arm and that upon downwardmovement of the arm, the curved end will move between the lowermost tack 41 and adjacent'upper tack, separating the lowermost tack from the line of tacks held in the magazine allowing the lowermost tack to assume a position as shown in dotted lines in FIG. 2 of the drawings, and within the path of travel of the hammer rod 27 which seats the tack upon sudden forward projection of the hammer rod.

' Secured to the upper end of the pivoted arm 39 and extending laterally therefrom, is a short rod 44 that operates in a slot 45 of the lower arm 46 of the bell crank 47 which is pivotally mounted at one side of the maga zlne.

Swiveled on the upper arm of the bell crank lever 47 is a bearing member 48 which is formed with an opening to receive the threaded end of the actuating rod 49, which actuating rod 49 has its rear end extended downwardly at 50 and forwardly at 51, the forwardly extended end 51 being disposed through the opening 52 formed axially of the cap 12, from which the forwardly extended end 51 passes through the opening 53 of the cap 11 that closes the rear end of the hammer rod barrel 10, as clearly shown by FIG. 2 of the drawings. Thus, it will be seen that due to this construction, the forwardly extended end 51.of the actuating rod 49 normally lies in the path of travel of the rear end of the hammer rod 27 and is engaged by the hammer rod as the hammer rod moves to the limit of its rearward position, thereby operating the rod 49, which results in the movement of the pivoted arm 39 to release a tack into the path of travel of the hammer rod 27, for positioning as described.

The magazine 36 embodies separable sections which are held together by means of bolts 53' and 54, which extend transversely through the sections of the magazine, the latter bolt constituting the pivot for the bell crank lever 47, thereby providing a structure which may readily be assembled.

The forward end of the head 7 is formed with a recess in which the curved lower ends of the sections of the magazine are held.

Mounted for sliding movement on the forward end of the tubular extension of the head 7, is a supporting ring 55 which is formed with slots 56 extending inwardly from the outer end thereof, in which the pivoted jaws 57 operate on their bearings 58 at their inner ends, while the outer ends of the jaws extend through slots 59, which slots are formed in the tubular extension of the head 7 adjacent to the dischargeend thereof. These pivoted jaws 57 are normally biased inwardly towards the body portion 5, by means of the coiled springs 60, which spring's have one of their respective ends secured to the head 7 at.61, while the opposite ends'thereof are secured to the supporting ring 55 at 62. s

The pivoted jaws 57 have their forward ends formed with stops 63 that are so constructed that they will engage the heads of the tacks as' they are driven forwardly by the hammer rod, holding the tacks in the proper positions in securing an article. I v A coiled spring 64 in the form of a ring, is positioned around the pivoted jaws 57 and rest in recesses 57 formed in the outer surface of said jaws, as shown by FIG. 2 ofthe drawings. Thus it will be seen that due to this construction, the tacks which are being positioned, will be held indirect alignment with the work being secured by the tacks delivered with the tool.

The barrel 5 is provided with a block 65 to which the upper end 66 of a handle 67 is secured, the handle affording means for holding and manipulating the hammer as desired V 7 As better shown by FIG. 2 of the drawings, the handle is provided with a bore 68 that communicates with the interior of the body portion 5, at a point between the cup washer 17 and end of the head 7 that connects with the body 5. One end of the bore 68 is enlarged and interiorly threaded to receive the threaded coupling 69 of an air hose 70 that. connects with, a suitable source of compressed air, not shown. Through this bore 68 air is directed to the chamber 19 .or space between washer or gasket '17. and the rear end of the head 7 to force the cam sleeve 15 rearwardly whereupon the cams 20 are moved outwardly releasing the hammer rod to the action of the coiled spring 28 operating thehammer rod to set a tack moved in the path of travel of hammer rod 27.

An outlet passageway in the form of a bore 71 also extends longitudinally through the handle 67 and communicates with the chamber 19 between the washer or gasket 17 and the inner end of the head 7 so that air which enters the chamber 19 to operate the cam sleeve 15, may exhaust to allow the coiled spring 14 to permit the return of the cam sleeve 15 to the forward end of the tool or to the limit of its forward movement for further operation towards the rear end of the tool under air pressure admitted through bore 68.

A slide valve 72 is disposed within the handle and is normally urged to'its outermost position by means of coiled spring 73 that is seated in a recess formed in one end of the valve 72 with one end of the spring contacting the inner end of the bore in which the valve 72 is mounted.

The valve 72 is formed with an opening 74 which is so constructed and arranged that it will normally register with the bore 71 releasing air from the chamber of the body 5.

This opening 74 also communicates with the bore 68 when moved to its rear position to 'allow air under pressure to pass into the chamber of the body 5 and simul-' taneously close the bore 71.

As shown by FIG, 5 of the drawings, the valve "is formed with a stem 75 which projects through the nut 76 in one end of the bore in which the valve 72 operates.

This stem extends beyond the nut 76 and is engaged by the trigger 77 pivotally connected to the handle 67 at 78. This trigger is so disposed that the person gripping the handle 67 may operate the trigger with the index finger of the hand.

In operation the hammer is positioned with the nozzle of the tool resting against the furniture to receive the tack in securing upholsterers cloth. The trigger 77 is now operated to move the valve 72 rearwardly until the opening 74 registers with bore 68, the bore 71 being closed. The air under pressure will enter the chamber 19 of the body 5 between the cup washer or gasket 17 and inner end of head 7, forcing the cam sleeve 18 rearwardly against the combined action of the spring 14 and 28, with the result that the hammer rod which is connected with the sleeve 15 through the medium of the cams 20, will be moved to the rear end of the hammer rod barrel 10. It is obvious that as the cams move upwardly over the inclined ends 24 of the slots 23 the cams will be moved out of contact with the shoulder 30 of the hammer rod 27, releasing the hammer rod to the action of the compressed spring 14, which projects the hammer rod 27 with such force as to set a tack which has gravitated into the path of travel of the driving end of the hammer rod.

When a tack has been set by the hammer it is obvious that the adjacent upper tack will fall into the bore of the head 7 to be set in a manner as described, by the succeeding action of the hammer rod.

By the continuous operation of the trigger 77 it will be obvious that the seating of the tacks will be continuous, until the supply of the tacks in the magazine has been exhausted.

In view of the foregoing detailed disclosure it is believed that further description as to the operation of the pneumatic hammer is unnecessary.

Having thus described the invention, what I claim is:

l. A tool of the class described, comprising a cylindrical body, a handle secured to said body by means of which the tool is manipulated, a hammer rod barrel mounted within said cylindrical body, a hammer rod slidable longitudinally within said hammer rod barrel, fluid controlled mechanism embodying a cam sleeve adapted to move said hammer rod rearwardly to set position within said cylindrical body, a coiled spring fitted in said hammer rod barrel against which said hammer rod moves tensioning said spring, means for releasing said hammer rod to the action of said tensioned coil spring projecting said hammer rod forwardly driving tacks fed into the path of travel of said hammer rod.

2. A tool of the class described, comprising a cylindrical body, a handle secured to said body for eflecting manipulation of said tool, a hammer rod barrel mounted within said body, said hammer rod barrel having longitudinal slots in the wall thereof, one of the end walls of each slot being inclined, a hammer rod having an annular shoulder, mounted for sliding movement within said hammer rod barrel, a cam sleeve having cam openings in the wall thereof, slidable on said hammer rod barrel, cams carried by said cam sleeve, slidable through said openings and slot engageable with said shoulder of said hammer rod connecting said cam sleeve to said hammer rod, a washer mounted on said cam sleeve contacting the wall of said cylindrical body providing an air chamber with one end of said cylindrical body, mechanism for directing air under pressure to said chamber moving said cam sleeve and hammer rod rearwardly, said cams moving over said inclined end walls of the slots disconnecting said cam sleeve and hammer rod, and mechanism for projecting said hammer rod forwardly when disconnected for contact with tacks fed into said housing setting said tacks.

3. A tool of the class described, comprising a cylindrical body, a handle for effecting manipulation of said tool, a hammer rod barrel within said cylindrical body, a hammer rod slidably mounted within said hammer rod barrel, a cam sleeve slidable on said hammer rod barrel, a washer carried by said sleeve contacting with said cylindrical body providing an air chamber within said cylindrical body, means for directing air under pressure to said air chamber for moving said cam sleeve rearwardly within said cylindrical body, mechanism for releasing said cam sleeve and hammer rod upon movement of said cam sleeve to the limit of its rearward movement, and mechanism for projecting said hammer rod forwardly against tacks successively delivered in the path of travel of said hammer rod, positioning said tacks.

4. A tool of the class described, comprising a cylindrical body, a tapered head having a bore, closing one end of said cylindrical body, a hammer rod barrel mounted within said cylindrical body aligning with said bore of the tapered head, said hammer rod barrel having longitudinal slots formed in the wall thereof, a hammer rod having an annular shoulder formed thereon mounted for sliding movement in said hammer rod barrel, a cam sleeve mounted for longitudinal sliding movement on said tubular housing, said sleeve having openings in the wall thereof, spring pressed cams mounted within said openings extending through said slots adapted to engage said shoulder of the hammer rod, connecting said cam sleeve and hammer rod, a washer mounted on said cam sleeve contacting the wall of said cylindrical body, providing an air chamber within one end of said cylindrical body, and mechanism for directing air under pressure to said air chamber moving said cam sleeve and hammer rod rearwardly within the cylindrical housing, cam surfaces on said hammer rod barrel over which said cams move forcing said cams outwardly and disengaging said hammer rod and cam sleeve, and a coiled spring for projecting said hammer rod forwardly into said tapered head for contacting with tacks delivered to said tapered head.

5. A tool of the class described, comprising a cylindrical body, a handle for effecting manipulation of said tool, a hammer rod barrel within said cylindrical body, a hammer rod slidably mounted within said hammer rod barrel, a cam sleeve slidable on said hammer rod barrel, a washer carried by said sleeve contacting with said cylindrical body providing an air chamber within said cylindrical body, means for directing air under pressure to said air chamber for moving said cam sleeve rearwardly within said cylindrical body, mechanism for releasing said cam sleeve and hammer rod upon movement of said cam sleeve to the limit of its rearward movement, a coiled compression spring mounted on said hammer rod barrel,

normally urging said cam sleeve to its initial position, and

a coiled compression spring mounted within said hammer rod barrel contacting with said hammer rod adapted to project said hammer rod forwardly for contacting tacks fed into said housing, independently of said first mentioned spring.

References Cited in the file of this patent UNITED STATES PATENTS 2,792,571 Klopstack May 21, 1957