US1721708A - Guard for shaper heads - Google Patents

Description

July 23, 1929.

c. J. NELSON 1,721,708

GUARD FOR SHAPER HEADS Filed Feb. 20, 1928 2 Sheets-Sheet l INVENTOR.

ATTORNEY.

July 23, 1929. c, NELSON 1,721,708

GUARD FOR SHAPER HEADS Patented July 23, 1929.

UNITED STATES CARL JOHN NELSON, OF BERKLEY, MICHIGAN.

GUARD FOR SHAPER HEADS.

Application filed February 20, 1928.

This invention relates to guards for enclosing vertical wood shapers, which rotate at very high speeds, to prevent injury to the operators, and thereby not only to protect the operators but to relieve them of the severe mental tension which reduces their efliciency to such an extent that their output falls off seriously during the later hours of the working day. The contant danger from unprotected cutting tools of this character is so great that the operators involuntarily slow down because of mental strain long before physical fatigue sets in, as has been demonstrated by comparisons of results obtained with the same machines before and after my guards for theshaper heads were installed.

This invention consists of a guard shell which normally encloses the shaper-head and the knives mounted thereon until the work is moved toward it and then rises to uncover the shaper knives to a predetermined extent to permit the operator to press the work against the cutters, the guard coming down to protective position as soon as the work is moved away from the cutters, in combination with pneumatic means for actuating the guard and a pneumatic valve which is actuated by the work and which controlsfthe operation of the guard.

It further consists of the details of construction illustrated in the accompanying drawings and particularly pointed out in the claims.

In the accompanying drawings, Fig. 1, is a plan of a wood shaper equipped with any novel guard. Fig. 2, is an elevation of this guard, the shaper head being shown in dotted lines. Fig. 3, is a section on the line 33 of Fig. 2. Fig. 4, is a vertical section of the actuating mechanism for the guard. Fig. 5, is a vertical section of the control valve.

Similar reference characters refer to like parts throughout the several views.

The well known cutter head 1 shown in plan in Fi 1 is usually rectangular in crosssection an to it are attached the knives 2, the head being mounted on a shaft 3 which projects upwardly from the table 4. The upper end of the shaft is journaled in a bracket 5 carried by a post 6 which projects upward from a base 7 secured to the table 4. As these heads rotate as high as eight to ten thousand rotations per minute, the danger Serial No. 255,542.

to the hands and arms of the operators is apparent, especially where work is duplicated to such an extent that the operations become mechanical.

In my novel construction, a hub 10 is at-, tached to the base 7 and a round vertical post 11 is mounted in this hub. The upper end 12 of the post is reduced in diameter and on the lower end is slidable a head 13 carrying a key 14 slidable in a key-way 15 shown by a dotted line in Fig. 4, and this key is positioned by the pins 16 and screw 17. A second head 18 is slidable on the upper end of the post and is provided with a stuffing box 19. A cylinder 21 is held between the heads by means of' four bolts 20. The lower head is provided with a vent passage 23 to prevent air being compressed in the lower end of the cylinder.

A piston is mounted on the'post and consists of two disks 24 pressed toward each other by a nut 25 and a packing ring 26 is held between the beveled edges of the disks and pressed against the .interior wall of the cylinder. Air under pressure is conducted to the longitudinal bore 27 of the post by a pipe 28 and flows into the space above the piston through passages 29 above the piston and raises the cylinder and the heads. This movement is limited by an adjustable clamp 30 shown in Figure 3.,

The heads are preferably square in plan and the shell 33 is secured to these heads by screws 36, being formed of two parallel sides 32 and a semi-cylindrical end 34. A reinforcing strap 35 and two short plates 37 may be used, if desired. The guard is elevated by air pressure but descendsby its own weight, the fall being cushioned by a rubber collar 38. The movements of the guard are controlled by the valve shown in Fig. 5.

A valve body 40 is provided with a cylindrical lining 41, held in position by means of the collars 42 and 43. The pipe 44 connects to a source of air under pressure while the pipe 28 connects to the guard. A cylindrical valve 45 has a circumferential groove 51 which connects the ports 46 and 46 when the valve is depressed by work sliding on the table 4 coming in contact with the rounded knob 48 which is adjustably mounted on the valve. The lower end of the valve is formed with a central bore 52 which receives a spring 49 and with an exhaust port 50 which connects to this central bore. The lower colwhen not in use.

lar 43 has an exhaust opening 53 to permit air passing from the pipe 28 through the port and bore- 52 toescape to the atmosphere.

The parts are normally in the position shown in the drawings. When work is slid on the table toward the shaper head, it passes over the button 48 and depresses it against the pressure of the light spring 49. Air rushes from the pipe 44 through port 46, grove 51, second port 46, pipe 28, passage 27 in post'll and passages 29 into the space between the piston 24 and head 18 and forces the guard up until it is stopped by the clamp 30'. lVhen the Work is finished,

it'is moved back from over the button 48 which permits'the spring 49 to raise the valve. The airin the cylinder-now escapes through the passages 29 and 27, pipe 28, ports 46 and 50, bore 52 and opening 53 to the atmosphere, permitting the guard to slide down over the shaper head. movements of the guard are very rapid so that. the shaper head is enclosed'at all times The position of the but ton 48- relative 'to the shaper head will be determined by the character ot'the work.

The details of construction'and the proportion of the parts may all be changed by those skilled in the art without departing from the spirit ofmy invention as set forth in the following claims.

1. A guard for a shaper head comprising a vertically movable shell adapted toenclose said head, a vertical post having a. 1011-- gitudinal passage, a cylinder, heads at the ends. of the cylinder slidable on the post, a

piston for the cylinder secured to the post, 1

a valve adapted to be. positioned by the Work presented to the cutter head, a pipe connecting the valve to a source of air under pressure and a pipe connecting the valve to thepassage in said post.

2.A guard for a shaper head comprising a vertically movable shell adapted to enclose said head, a cylinder attached to the shell, a

piston within the cylinder, a hollow piston.

rod: and. a: pipe connecting thereto to permit The move said valve.

air to pass into and out of the cylinder to cause it to move up, a valve body adjacent the cutter head having a vertical bore and two ports, a pipe connecting to a source of air under pressure and to one of said ports, the other port connecting to said piston rod by said first named pipe, a valve slidable within said valve body and provided with a transverse passage which connects said ports when depressed and with an exhaust passage which connects to the second named port when said valve is elevated, a spring to elevate the valve, and a button attached to the upper end of the valve and adapted to be depressed by Work being presented to the shaper head. 1

3. A guard for a shaper head comprising a vertically movable shell having parallel sides and a semi-cylindrical end adapted to enclose said head, a vertical post having a longitudinal bore, a-cylind'er, rectangular heads at the ends of the cylinder slidable onsa-id post to which heads the parallel sides of theshell are attached,'a piston for said cylinder attached to said post Whose bore terminates above said piston, and a Valve tocontrol the flow of air under pressure to the bore of said post.

4-. A guard for a'shaper head comprising a stationary part and a vertically movable part, said part-s embodying an air cylinder and a piston therein, means to conduct air to and from said cylinder, a valve body ad jacent the shaper head, a piston valfve therein, pipes connecting said valve body to the guard and to a source of air under pressure, and means 1n the path of the work to 5. A guard for ashaper head comprising a stationary part and a vertically movable part, said parts embodying a cylinder and a piston therein, means to conduct fluid under pressure to and from said cylinder, a valve mechanism adjacent the shaper head, pipes connecting said valve mechanism to the guard and to a source of fluid under pressure, and means in the path: of the work to operate the valve mechanism.

CARL JOHN NELSON.

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