US3225878A - Safety locking apparatus to render inoperative machine tools and the like - Google Patents

Description

3,225,878 ATIVE Dec. 28, 1965 J. ESTEPHANIO SAFETY LOCKING APPARATUS TO RENDER INOPER MACHINE TOOLS AND THE LIKE 7 Sheets-Sheet 1 Filed March 26, 1963 INVENTOR JOS asmmmmo ATTORNEYS Dec. 28, 1965 Filed March 26, 1963 MACHINE TOOLS AND THE LIKE 7 Sheets-Sheet 2 INVENTOR J0$ ESTEPHA/V/O ATTORNEYS Dec. 28, 1965 ESTEPHANIQ 3,225,878

SAFETY LOCKING APPARATUS TO RENDER INOPERA'IIVE MACHINE TOOLS AND THE LIKE Filed March 26, 1963 7 Sheets-Sheet 5 F/az ATTORNEYS Dec. 28, 1965 J. ESTEPHANIO 3,225,878

SAFETY LOCKING APPARATUS TO RENDER INOPERATIVE MACHINE TOOLS AND THE LIKE Filed March 26, 1963 '7 Sheets-Sheet 4 INVENTOR J05! S'IEPA 4IV/U ATTORNEYS Dec. 28, 1965 J. ESTEPHANIO 3,225,878

SAFETY LOCKING APPARATUS T0 RENDER INOPERATIVE MACHINE TOOLS AND THE LIKE 7 Sheets-Sheet 5 Filed March 26, 1963 INVENTOR JOS ESTEPHA/V/O 792084004 jouk ATTORNEYS Dec. 28, 1965 ESTEPHANIQ 3,225,878

SAFETY LOCKING APPARATUS TO RENDER INOPERA'IIVE MACHINE TOOLS AND THE LIKE Filed March 26, 1965 7 Sheets-Sheet 6 FIG. 8

INVENTOR JOSE ESTA'P/l/i/V/O AZZUWKM ATTORNEYS E K I L mm mm mm Em To E .E m H C A M Dec. 28, 1965 3,225,878

SAFETY LOCKING APPARATUS TO RENDE'R INOPERATIVE Filed March 26, 1965 7 Shets-Sheet v m 3 TA NP E5 m m w ew- M ATTORNEYS United States Patent 3,225,878 SAFETY LOCKING APPARATUS T0 RENDER IN- OPERATIVE MACHINE TGQLS AND THE LIKE Jos Estephanio, Rua Bnenos Aires 310, Rio de Janeiro, Brazil Filed Mar. 26, 1963, Ser. No. 268,097 Claims priority, application Brazil, Oct. 22, 1962, 1 ,038 11 Claims. (Cl. 192-429) This invention relates to the protection of workers against accidents in industrial plants.

More specifically, the invention provides for a safety apparatus to be adapted to certain dangerous machines such as are more likely to cause serious and permanent injuries to their operators.

Such safety apparatus, briefly stated, is adaptable to such machines, and comprises an oscillatable arm which sweeps the path of the movable parts of the machine which are likely to cause injuries. Such sweeping movement is carried out by the oscillatable arm being oscillated by the main driving means of the machine, so that no failure of the driving power will impair the safety requirements of the device. The movement of the oscillatable sweeping arm is so timed as to be effected immediately before the movement of the dangerous moving parts of the machine.

The sweeping arm holds at its operative end a cocked device which is released if it meets any obstacle, such as, for instance, the operators arm, in the path of the dangerous moving parts of the machine to which it is attached. The release of the device actuates certain locking means which will lock the machine and render it inoperative.

The utmost care has been taken to render the apparatus of the invention foolproof. The following description of the apparatus and of its operation will show that this aim has been attained.

The apparatus of the present invention is designed to contribute to the reduction or elimination of industrial accidents. The first Iber0-American Congress of Social Security disclosed in 1956 that the many methods in use to secure physical protection to the industrial worker are incomplete, many being practically inefficient, and all leave a wide margin for improvement. It was also disclosed at that time that in the United States alone, during 1949, no less than 4,650,000 casualties occurred in American industry.

There is now an ever-increasing demand for solutions to this serious social problem, and even the I.L.O. (International Labor Organization) is earnestly tackling the matter, trying by every possible means to prevent or to reduce the rate of accidents in industry.

Tests have been carried out to locate and reduce the causes.

In the investigation resulting in the present invention, attention was directed particularly to reducing industrial accidents, to the apparent causes of such accidents, and to the field of the greater incidence thereof. Thus, it has been ascertained that, in automatic press machines, the number of accidents reaches the order of thousands, these accidents crippling and maiming the hands and arms of operators. To reduce this toll of injuries, the apparatus of the present invention was developed and is in fact a safety apparatus which operates simultaneously with the press machine to which it is adapted, although in advance of the actual operation of the machine, as mentioned above.

It is understood that the apparatus of the invention can be employed in connection with a great variety of dangerous machines, with minor adaptations evident to those skilled in the art. In the detailed description be- "ice low, and in the accompanying drawings, it is understood that the apparatus is connected to a press machine for the sake of exemplification and clarification only, such description and such drawings in no way limiting the scope of the invention which is set forth in the appended claims.

In the attached drawings:

FIG. 1 shows a conventional eccentric press machine whereon the apparatus is mounted, with the trigger device on the area sweeping arm cocked for safety action;

FIG. 2 is another view of the press machine with the trigger device released after having been actuated by hitting an obstacle;

FIG. 3 shows in detail the safety apparatus of the invention, all the conventional parts of the press machine being drawn in dot-and-dash lines;

FIG. 4 shows the members of the apparatus which transmit movement from the machine driving means to the sweeping device;

FIGS. 5 and 6 show, respectively, the area sweeping device and the trigger device;

FIG. 7 shows the locking system actuating device, the press machine being operatively free;

FIG. 8 shows the same system, the press machine being operatively locked;

FIGS. 9 through 15 show isolated parts of the apparatus.

The safety apparatus of the invention is illustrated, in the drawings, as mounted on an eccentric type press having a conventional reciprocable head 1 which, as best seen in FIG. 4, has attached thereto a horizontal arm 2 extending perpendicularly therefrom. One end of an intermediate arm 3 is attached to the free end of arm 2, and the lower end of intermediate arm 3 has an arm 4 extending therefrom parallel to arm 2. A slide 5 is adjustably secured to arm 4 and is formed with a rack 6. Slide 5 is slidably mounted on a fixed guide 7 and, during sliding movement, its rack 6 rotates a spur gear 8, as best seen in FIGS. 3 and 9. A bevel gear 9 is integral with gear 8 and meshes with a bevel pinion 10 secured to a tubular axle or sleeve 11 adjacent the upper end of the latter. The lower end 12 of sleeve 11 is mounted in a seat 13, with the upper end of sleeve 11 being supported by a bearing ring 14.

A cylindrical stem, or inner shaft, 15, is slidably mounted inside sleeve 11. The area sweeping arm 18 is mounted on bracket member 16 on sleeve 11 so as to pivot horizontally (see also FIGS. 56) across the operation path of the press head, in a sweeping movement, imparted by the angular movement of tubular sleeve 11. Such angular movement is caused by the action of rack 6 on gears and pinions 8, 9 and 10. As rack 6 is permanently attached to the conventional head 1 of the press machine by members 2, 3 and 4, it will move together with head 1.

Bracket 16 is fixedly mounted on axle 11, being held in place by screw 17. Sweeping arm 18 projects from bracket 16, and has slidably telescoped therein an inner shaft 19 having one end fixed to radial lever 20 (FIG. 15) engaged in aperture 21 of shaft 15, so as to produce a vertical movement of shaft 15. A space is provided inside arm 18 to receive a coil spring 22 embracing shaft 19 and having one end permanently held in place while its other end is regulatably set in any of a number of holes 23 radially disposed in member 24 so as to urge member 24 downwards. Member 24 is traversed by shaft 19 and is fixed thereto, so as to impart to shaft 19 any radial movement whenever action of spring 22 is released. Member 24 has a hooked arm or catch 25 which engages its counterpart catch 29 fixedly mounted on abutting bar 26, which latter is parallel to arm 18 and fixed thereto by pins provided with springs 27 housed in projections 28 of arm 18. These pins are retractable into projections 28 against the bias of springs 27. The engagement of catches and 29 is obtained by shifting abutting bar 26 toward arm 18 and against the bias of springs 27.

Abutting bar 26 constitutes the trigger device of the apparatus. Whenever it strikes an obstacle during the sweeping movement of arm 18, it is pressed towards said arm and disengages catches 25 and 29. Member 24- will then be free to rotate by the pull of coil spring 22, and will impart rotary movement to inner shaft 19 on which it is fixedly mounted. The radial movement of inner shaft 19 will be transmitted to radial lever 20 at its other end, and this will move shaft 15 downwardly inside tubular shaft 11.

The downward movement of shaft 15 will naturally cause its upper end to retract downwards (FIG. 3) pulling down a transverse rod to which it is attached. At its inner end, rod 30 is pivotally mounted, by means of a pin 31, on a member 32 fixed to the body of the machine. A pin 33 pivotally connects the slotted outer end of arm 38 to a bent vertical arm 34, as best seen in FIGS. 3 and 8. By means of a pivot pin 36, the upper end of bent or curved arm 34 is pivotally secured to a free end of a lever 35. The other free end 37 of lever is arranged to be disposed in the path of movement of a sleeve 38 slidably mounted on a rod 39. Sleeve 38 is biased along rod 39 by a compression coil spring 40 embracing rod 39 and disposed between sleeve 38 and a fixed sleeve 41 adjustably secured to rod 39. A spring 57, illustrated per se in FIG. 13, biases lever 35 clockwise, as viewed in FIG. 8, to bias its end 37 downwardly.

Rod 39 is displaceable longitudinally of itself through a seat hole bored through the frame of the machine. The extent of the longitudinal displacement of rod 39 is limited by a transverse retaining member 43, shown in detail in FIG. 10, fixed to the frame of the machine by a bolt 44 extended outwardly to form the pivot of lever 37. This retaining member 43 engages in a notch in an enlargement 42 of rod 39.

The inner end of rod 39 engages a horizontal key member 45 extending at right angles thereto. Member 45 serves to obstruct the operating path of the head of the press, by engaging its notched end 54 with a notched portion 55 of the head of the press. The inner end of rod 39 engages a dual notch 46, 56 of key member 45.

Key member 45 is slidable in a cylindrical passage in the frame of the machine, being based by a coaxial coil spring 50. This key member is locked in place by the inner end of rod 33 when such inner end engages the deeper portion 46 of notch 46, 56 (FIGS. 3 and 8). Thus key member 45 is allowed two positions: a retracted position leaving the machine operatively free, when the end of rod 39 engages the deeper notch 46 and an advanced position, wherein the inner end of rod 39 engages the shallower notch 56, and key member 45 obstructs the path of the head or striking member of the machine.

Normally the parts occupy the position of FIG. 7 in which end 37 of lever 35 is engaged between sleeve 38 and the outer end of enlarged portion 42 of rod 39, and in which retaining member 43 is engaged against the left hand edge of the notch in enlargement 42. Under these conditions, and with the inner end of rod 39 engaged in the deeper step 46 of the double notch in member 45, spring 40 is considerably compressed. When contact device 26 strikes an obstruction during oscillation of arm 18, and the shaft 15 within shaft 11 is pulled down by radial lever 21, rod 30 and bent arm 34 are pulled downwardly. This lifts the end 37 of lever 35 which frees both sleeve 38 and rod 39. Due to the reaction under the bias of compressed spring 40, sleeve 38 strikes against the frame of the machine, this sleeve being larger than the rod 39 or its enlarged portion 42 so that it cannot pass through the seat hole. The combined reaction biases rod 39 to the left, as viewed in FIG. 7, and the parts now occupy the position of FIG. 8 wherein the inner end of rod 39 is seated in a shallower notch 56 of the double notch of member 45. Spring 59 thus biases key member 45 to the right, as viewed in FIGS. 7 and 8, so as to position its abutment surface 54 in the path of downward movement of machine head 1. The notched end 54 of key member 45 will thus engage the notch portion 55 of head 1. In such case, retaining member 43 engages the inner end of the notch in enlargement 42 thus limiting outward movement of rod 39 to a position in which its inner end is still seated in a shallower notch 56.

The shifting of key member 45 is transmitted to another rod 51 extending at right angles from member 45. Rod 51 is connected, by a link or tie rod 52, with the operator of a switch 53 so that, upon movement of key member 45 to the right to interrupt downward movement of the pread head, the power supply to the machine is interrupted, thus avoiding undesirable slipping of transmission belts when movement of the machine is obstructed.

To reset the parts, key member 45 is pushed to compress spring 50 until the inner end of rod 39 can engage in the deeper notch 46. The rod 39 is then moved to the right, with spring 38 being held back, to engage the end 37 of lever 35 between sleeve 38 and the outer end of enlargement 39. The resultant pivoting movement of lever 35 pulls rod 35) and shaft 15 upwardly, rotating shaft 19. Contact member 26 is then pushed inwardly so that the hooks 25 and 29 may be reenacted.

From the foregoing, the functions, the utility and the operation of the apparatus of the present invention will be seen readily.

It will also been seen from the foregoing that although the invention is illustrated in connection with an eccentric press machine, it can be readily adapted to any other operating machine, by having the same force that actuates the movable parts likely to cause injuries to actuate also an area sweeping arm mounting a cocked trigger device, releasable by hitting an obstacle, such device instantaneously and efiiciently locking said movable parts, as illustrated and described.

It may further be said that the operation of the safety apparatus includes the transmission of movement of the press head shaft by means of an arm and rack, to the shaft whereon the sweeping arm oscillates. Thus, to each reciprocating up-and-down movement of the press head corresponds a to-and-fro movement of the oscillatable sweeping arm across the Working area. The trigger device carried at the end of said sweeping arm is cocked, being releasable by any light impact; its releasing will cause the inner shaft of the sweeping arm to turn around its axis, lowering a vertical shaft which actuates a system of levers which will cause the retraction of a catch member, releasing a key member which is pushed forward and intercepts the shaft of the press head in its downward movement, interrupt such movement.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

I claim:

ll. In combination with a machine tool having a work space, a work-engaging member movable into said work space, and driving means for said work-engaging memher; a safety arrangement comprising, in combination, a work space sweeping arm pivotally mounted on said machine for swinging through said work space; driving mechanism connecting said arm to said driving means for swinging of said arm in synchronism with movement of said work-engaging member, said driving mechanism swinging said arm through said space immediately in advance of movement of said work member into said space; detector means, including an element on said arm, operable responsive to engagement of said element with an obstruction in said space, to interrupt operation of said machine tool; said detector means element com-prising a striking device on the free end of said sweeping arm and extending substantially parallel thereto; means movably mounting said striking device of said sweeping arm for movement toward and away from said sweeping arm; spring means biasing said striking device outwardly of said sweeping arm; a first inner shaft extending longitudinally of said sweeping arm and rotatably mounted therein; spring means operatively associated with said shaft and biasing the same to rotate in a selected direction; and interengageable catch means on said striking device and said shaft effective to retain said shaft against rotation by said spring means; said interengaging catch means being released upon said striking device engaging an obstruction in said work space.

2. A safety arrangement fora machine tool, as claimed in claim 1, wherein said tubular shaft extends vertically and said first gear is mounted on the upper end of said tubular shaft; a rod telescoped through said tubular shaft and having an upper end projecting beyond the upper end of said tubular shaft; an operating arm swingably mounted on said machine and having a free end engaging the upper end of said rod; said detector means, responsive to engagement thereof with an obstruction, releasing said rod to move downwardly in said tubular shaft, and the resultant lowering of said operating arm effecting interruption of the operation of the machine tool.

3. A safety arrangement of a machine tool, as claimed in claim 1, wherein the means pivotally mounting said sweeping arm comprises a vertically extending tubular shaft rotatably mounted in said machine tool; means fixing said sweeping arm on the lower end of said shaft; a first gear secured to the upperend of said tubular shaft and intermeshing with a second-"gear included in said driving means; a rod telescoped through said tubular shaft for vertical movement therethrough and projecting above the upper end thereof; an operating arm swingably mounted on said machine and having a free end engaging the upper end of said rod; said rod being formed with apertures therein; said first inner shaft extending into said tubular shaft; a radially extending finger on the inner end of said first inner shaft engaged in one of said apertures; said finger, when said catch means are interengaged, maintaining said rod projecting upwardly from said tubular shaft and, upon disengagement of said catch means, moving said rod downwardly in said tubular shaft to drop said operating arm; said operating arm forming part of the means effecting interruption of operation of said machine tool upon dropping of said operating arm.

4. A safety arrangement for a machine tool, as claimed in claim 3, in which said detector means includes a springbiased component; catch means maintaining said springbiased component in a retracted position; and means interconnecting said catch means and said operating arm and operable, responsible to lowering of said operating arm, to release said catch means from said spring-biased means.

5. A safety arrangement for a machine tool, as claimed in claim 3, including a lever pivotally mounted on said machine tool; said detector means being operable to interrupt operation of said machine tool upon swinging movement of said lever; and means interconnecting said lever and said operating arm and effective to swing said lever upon lowering of said operating arm.

6. A safety arrangement for a machine tool, as claimed in claim 3, including a second rod mounted for longitudinal sliding movement in said machine tool; retaining means engageable with said second rod and limiting longitudinal displacement thereof; a first sleeve mounted on a projecting portion of said second rod for sliding movement therealong; spring means interengaged between said first sleeve and a fixed portion of said second rod; catch means engageable with said sleeve and normally maintaining said spring means compressed; said catch means being secured to said operating arm and engaged with said first sleeve in the upper position of said operating arm; said catch means being released upon downward movement of said operating arm to release said sleeve; said sleeve, when so released, and under the bias of said spring means, acting as a projectile moving along said second rod to strike the frame of the machine tool to move said second rod in the reverse direction through its limited movement as determined by said retaining means.

7. A safety arrangement for a machine tool, as claimed in claim 6, including a second sleeve securable in adjusted fixed position to said second rod; said spring means embracing said second rod between said first and second sleeves.

8. A safety arrangement for a machine tool, as claimed in claim 7, including a third rod mounted for sliding movement in the machine tool frame at right angles to the direction of sliding movement of said second rod; means biasing said third rod for movement in a selected direction; said second rod having an end engaged in notch means in said third rod and normally restraining said second rod against movement in said selected direction; said third rod, upon retraction of said second rod, moving in said selected direction to interrupt operation of said machine tool.

9. A safety arrangement for a machine tool, as claimed in claim 8, in which said third arm has a free end movable into the path of movement of said work-engaging member to mechanically interrupt movement of the latter.

10. A safety arrangement for a machine tool, as claimed in claim 8, in which said driving means is electrically operated; a switch controlling operation of said driving means; and means interconnecting said third rod and said switch and operable, upon movement of said third rod in said selected direction, to open said switch to deenergize said driving means.

11. A safety arrangement for a machine tool, as claimed in claim 8, wherein said notch means in said third rod comprises two adjacent notches of different depths; said second rod normally being engaged in the deeper notch and being retracted from the deeper notch upon release of said first sleeve; said second rod thereupon engaging the shallower notch to limit movement of said third rod in said selected direction.

References Cited by the Examiner UNITED STATES PATENTS 1,084,631 1/1914 Hazel et a1 74615 1,648,232 11/1927 Ischinger 74615 2,030,976 2/1936 Fairfield et a1 192-134 2,524,090 10/1950 Swan 74614 FOREIGN PATENTS 728,909 4/1955 Great Britain. 1,251,389 12/1960 France.

DAVID J. WILLIAMOWSKY, Primary Examiner.

Claims (1)

1. IN COMBINATION WITH A MACHINE TOOL HAVING A WORK SPACE, A WORK-ENGAGING MEMBER MOVABLE INTO SAID WORK SPACE, AND DRIVING MEANS FOR SAID WORK-ENGAGING MEMBER; ASAFETY ARRANGEMENT COMPRISING, IN COMBINATION, A WORK SPACE SWEEPING ARM PIVOTALLY MONTED ON SAID MACHINE FOR SWINGING THROUGH SAID WORK SPACE; DRIVING MECHANISM CONNECTING SAID ARM TO SAID DRIVING MEANS FOR SWINGING OF SAID ARM IN SYNCHRONISM WITH MOVEMENT OF SAID WORK-ENGAGING MEMBER, SID DRIVING MECHANISM SWINGING SAID ARM THROUGH SAID SPACE IMMEDIATELY IN ADVANCE OF MOVEMENT OF SAID WORK MEMBER INTO SAID SPCE; DETECTOR MEANS, INCLUDING AN ELEMENT ON SAID ARM, OPERABLE, RESPONSIVE TO ENGAGEMENT OF SAID ELEMENT WITH AN OBSTRUCTION IN SAID SPACE, TO INTERRUPT OPERATION OF SAID MACHINE TOOL; SAID DETECTOR MEANS ELEMENT COMPRISING A STRIKING DEVICE ON THE FREE END OF SAID SWEEPING ARM AND EXTENDING SUBSTANTIALLY PARALLEL THERETO; MEANS MOVABLY MOUNTING SAID STRIKING DEVICE OF SAID SWEEPING ARM FOR MOVEMENT TOWARD AND AWAY FROM SAID SWEEPING ARM; SPRING MEANS BIASING SAID STRIKING DEVICE OUTWARDLY OF SAID SWEEPING ARM; A FIRST INNER SHAFT EXTENDING LONGITUDINALLY

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