US3654821A - Personnel safety guard for machinery - Google Patents

Abstract

A safety guard to prevent injury to personnel in connection with the operation of machinery. The guard comprises a plurality of horizontally disposed elongated panels supported in a closed position with the panels in substantially edge to edge relationship and combining to cover the hazardous area. Means is provided for moving the panels vertically in unison to an open position wherein the panels are in side by side stacked relationship to provide a clear area for access to the machine. The guard is arranged to be readily operated without effort by the operator and to provide optimum safety.

Description

United States Patent Mikulin 151 3,654,821 [451 Apr. 11, 1972 [54] PERSONNEL SAFETY GUARD FOR- MACHINERY [72] Inventor: Tom T. Mikulin, 1469 Bellevue Avenue,

Burlingame, Calif. 94010 [22] Filed: May 11, 1970 [21] Appl. No.: 36,266

52 U.S.Cl ..74/6l2,83/544, 100/53 51 1111.01 ..F16p3/00 [58] FieldofSearch ..74/608,616,615,614,613,

[56] References Cited UNIT ED STATES PATENTS 2,724,287 11/1955 Knoth ..74/6l6 FOREIGN PATENTSOR APPLICATIONS Great Britain Primary Examiner--William F. ODea Assistant Examiner-F. D. Shoemaker Attorney-Gordon Wood [57] ABSTRACT A safety guard to prevent injury to personnel in connection with the operation of machinery. The guard comprises a plurality of horizontally disposed elongated panels supported in a closed position with the panels in substantially edge to edge relationship and combining to cover the hazardous area. Means is provided for moving the panels vertically in unison to an open position wherein the panels are in side by side stacked relationship to provide a clear area for access to the machine. The guard is arranged to be readily operated without effort by the operator and to provide optimum safety.

4 Claims, 6 Drawing Figures PATENTEDAPR 11 I972 SHEET 1 OF 2 lii,

55 INVENTOR.

TOM T. MIKULI N 52 9 v i 6 11% W PATENTEDAPR 1 1 m2 SHEET 2 BF 2 INVENTOR,

TOM T. M IKUL I M PERSONNEL SAFETY GUARD FOR MACHINERY This invention relates to safety guards of the type employed to prevent injury to personnel from the operation of machinery. Heretofore the design of safety guards for machines has generally been considered a separate problem in each instance depending on the size, orientation, and the method of actuation of the machine. In most cases it is essential that the guard act as a barrier when the machine is in operation and at the same time be readily removed from the working area to permit access to the machine for purposes of adjustment, changeover, and correction of malfunctioning.

In many instances prior art safety guards have required a considerable amount of room especially when it is desired to open the guard to obtain access to the machine. In other instances the movement of the guard from open position to closed position and vice versa has required a considerable amount of work on the part of the operator thus causing delays and impairing the efficiency of the guarded machine.

The main object of the present invention is to generally improve safety guards for machinery and to overcome many of the disadvantages of prior art devices of like nature.

Another object of the invention is the provision of a safety guard for machinery which is readily opened and closed by the operator without great effort and with much more speed than has heretofore been possible.

Still another object of the invention is the provision of a safety guard which is designed to provide optimum effectiveness as a barrier and at the same time be easily opened and closed.

Other objects and advantages will be apparent from the following specification and from the drawings:

FIG. 1 is a front elevation of the guard with most of the panel actuating mechanism omitted because of the smallness of the scale.

FIG. 2 is a greatly enlarged fragmentary side elevation of the right hand side of the guard with portions broken away to show internal structure.

FIG. 3 is a vertical sectional view taken in a plane indicated by lines 3-3 in FIG. 2.

' FIG. 4 is a fragmentary end elevation showing the locking mechanism.

FIG. 5 is an enlarged horizontal sectional view taken in a plane indicated by lines 55 in FIG. 1.

FIG. 6 is a fragmentary horizontal sectional view through the lower end of the guard showing the locking mechanism.

In detail, and first with reference to FIG. 1., the guard is shown in its entirety but omitting mounting means including brackets that may be employed to secure it in a position covering the hazardous area. It will be understood in this connection that the guard may vary greatly in size depending upon the area to be protected. Furthermore depending on the particular machine involved the method of securing the guard in front of the machine will vary depending on the adjacent structure to which the guard is to be secured. In connection with the following disclosure it will therefore be understood that the frame of the guard must be mounted as desired in a fixed position depending on the particular environment involved.

The guard is provided with a peripherally extending frame including a pair of horizontally spaced end members 1, 2, and a top frame member 3. Said frame members are secured together by any convenient means to constitute the fixed support for the guard.

Extending horizontally between the side frame members 1, 2 are a plurality of panels 5. Each panel 5 may be divided into two parts as indicated in FIG. 1 in the event the length of the guard is fairly long. In many instances the guarded area is sufficiently narrow so that each panel may be made in one piece. Each panel is provided at its opposite ends with end pieces 6 which may be made from angle bar so that the panel material may be secured to one leg of the angle bar while the other leg provides means for pivotally supporting the panel.

In the particular guard shown in FIG. 1 upper panels 5A, 5B, 5C and lower panels 5F, 5G are provided with expanded metal 7 whereas the intermediate panels SD, SE are provided with transparent material such as a tough transparent plastic indicated at 8. By this arrangement an adequate barrier is pro vided when the panels are in closed position shown in FIG. 1 and at the same time the operator may view the operation of the machine indicated by dot dash lines at 10 in FIG. 1 through the transparent panels SD, SE.

The panels 5 are adapted to be moved from the closed position shown in FIG. 1 to an open position shown in dot dash lines in FIG. 3 in which the panels 5 are in substantially stacked relationship under the top 3 of the frame. In such open position it will be apparent that a generous access area is available through the frame permitting the operator to perform whatever functions are required on the machine.

The guard is moved from closed to open position by the operator by means of a horizontally extending hand bar 12 adjacent the lower frame member 4 of the guard. As will be explained in greater detail later on the panels 5 move in unison under the control of lazy tong mechanisms actuated by movement of the bar 12. In order to minimize the effort required by the operator in opening the guard counterweights 9 are provided which move from the upper position shown in FIG. 1 to a lower position as the panels 5 are raised to their upper position shown in dot dash line in FIG. 3. Smooth actuation of the guard is achieved by a parallel motion device which will now be described.

Rotatably supported at the lower ends of sides 1, 2 are pulleys 13, 14 around which is reeved a flexible wire. The inner runs 15, 16 of the wire extend from the pulleys 13, 14 up to connectors 17, 18 which in turn are pivotally connected to lower panel 5G in a manner to be described. The left hand inner run 15 continues up from the connector 17 to a small pulley 19 and then horizontally within the frame top 3 to an outer pulley 20 at the upper end of side frame member 2 and thence down to the right hand counterweight 9. From said counterweight the outer run 22 of the wire extends downwardly around pulley 14. In like manner the inner run 16 at the right hand end of the frame is reeved over a pulley 24, then along the top 3 and around a pulley 23 at the upper end of side frame member 1 thence down to the pulley 13.

From the above general description it will be seen that the wire insures parallel motion of the panels when the same are moved and at the same time the counterweights 9 may be adjusted in weight so that substantially no effort is required to move the guard from closed to open position and vice versa.

It will be understood that the invention also contemplates horizontal movement of the guard to a position alongside one of the end members 1, 2 of the frame.

Referring now to the details of the guard actuating means shown in FIGS. 2, 3, and 5 the upper panel 5A is pivotally connected by a pivot 27 to the lower end of a short link 25 which is swingably secured at its upper end to a rod 26 extending horizontally the length of the guard and secured at its opposite ends to end frame members 1, 2. Centrally between its opposite side edges panel 5A is provided at each end with a pivot pin 30 which is passed through a hole in the laterally outwardly facing flange of angle bar 6. Each pivot pin 30 is formed with an integral annular collar 31 (FIG. 5) which serves to space apart an outer link 32 carried at its opposite ends by panel 5A and an inner link 33 pivoted on pin 31 and pivotally connected at its upper end to the lower ends of a pair of links 23 (FIG. 3). It will be seen from FIGS. 2, 3 that the pair of links 23 are swingable at their upper ends on rod 26 together with link 25.

Each panel 5 is pivoted in like manner as panel 5A with the same linkage arrangement as above described except for the omission of short links 23, 25. Said lazy tong linkage arrangement permits the panels to be moved to their open position at the upper side 3 of the frame as indicated in dot dash lines in FIG. 3.

Referring to FIG. 5 the pin 30 is fixedly secured to the panel 56 by means of nut 34 and rotatably supported on each pin 30 is a roller 38 which is received within a slot 39 formed between the opposed flanges of a substantially channel shaped element 40. Said element 40 is fixedly secured to a similar channel shaped element 41 and together said elements constitute the side frame member 2. Left hand frame member 1 is similarly constructed.

The particular pin 30 carried by panel A is preformed with an extension 43 (FIG. 5) to which is secured the wire connector 18. From this structure it will be seen that the pins 30 move smoothly along the length of slot 39 under the control of rollers 38 when the panels 5 are moved.

As best seen in FIG. 5 counterweights 9 are secured by bolts 45 to slides 46 which include a portion 47 slidable within the slot 39 of channel 41.

Although the weight of counterweights 9 may be predetermined so that there is no tendency for the guard to open from its closed position shown in FIG. 1 it is nevertheless preferable to have said counterweights of such a weight that substantially no effort is required to actuate the guard.

Since vibration of the guarded machine may tend to open the guard from the closed position of FIG. 1 it is preferable to provide a positive locking means for retaining the guard in closed position. Such positive locking means is shown in FIGS. 2, 4, 6.

The hand bar 12 is fixedly secured at its opposite ends to the angle bars 6 of bottom panel 50 by means of brackets 50 which are shaped so as to position the hand bar at a point spaced outwardly from the vertical plane of the guard where said bar is readily grasped by the operator. Rotatably supported at its opposite ends in brackets 50 is a rod 51 to the opposite ends of which are secured bosses 52 by means of pins 53 (FIG. 6). Carried by the bosses 52 are small rollers 55 which are adapted to be received within notches 56 (FIG. 4) formed in plates 57 which in turn are integrally secured to the lower ends of sides 1, 2.

Integral with rod 51 and with each boss 52 is a plate 59 provided with a handle 60 by which the plate 59, boss 52 and rod 51 may be swung from an upper position indicated in dot dash lines in FIG. 4 to the lower full line position.

Plate 59 is provided with an extension 62 (FIG. 4) which is adapted to be received under a pin 64 carried by bracket 50 when the hand bar 12 is in its lowermost position. By employing the pin 64 as a pivot the operator may swing either plate 59 downwardly from the dot dash position of FIG. 4 so that the roller 55 is engaged within the notch 56. Such movement of plate 59 is performed with the hand bar 12 held downwardly in its lowermost position and against the resiliency of'the lazy tong mechanism above described. When roller 55 is thus received in notch 56 the mechanism is positively locked and there is no danger of vibration causing the panels 5 to creep upwardly to open position. When it is desired to open the guard a positive movement of bar 12 downwardly together with positive upward swinging of plate 59 is required to release the device from locked position. Since there is a plate 59 at each end of rod 51 either one may be operated.

In the event the panels 5 are required to be of such a length that support is required intermediate their length as indicated in FIG. 1 a lazy tong mechanism may be employed between the panel portions similar to that shown in FIGS. 2, 3.

The operation of the counterweights 9 may be made smooth and unnecessary noise eliminated by providing nylon pads 66 at the upper and lower ends of said counterweights. These pads are similar in shape to the rollers 38 and are adapted to slide within the adjacent slot 39 of the frame side.

I claim:

1. A safety guard adapted to be positioned adjacent a machine such as a punch press to protect personnel from injury comprising:

a vertically disposed frame defining a vertical working area centrally thereof,

a plurality of horizontally elongated panels of protective material,

means supporting said panels for movement in unison from a closed position with said panels approximately within said working area and combining to cover such area to an open position atone end of said frame with said panels in substantially side by side stacked relationship to provide access through said central area to such machine,

said panels being supported at their opposite ends by lazy tong mechanisms to permit such movement,

said frame being formed in its opposite vertically extending marginal portions with longitudinally extending slots for receiving therein the central pivots of said lazy tong mechanism.

2. A guard according to claim 1 wherein locking means is provided for positively holding said panels in closed position.

3. A guard according to claim 1 wherein movement of said panels is controlled by a parallel motion mechanism to insure pure translation of said panels.

4. A guard according to claim I wherein a counterweight is employed to facilitate movement of said panels upwardly to open position.

Claims (4)

1. A safety guard adapted to be positioned adjacent a machine such as a punch press to protect personnel from injury comprising: a vertically disposed frame defining a vertical working area centrally thereof, a plurality of horizontally elongated panels of protective material, means supporting said panels for movement in unison from a closed position with said panels approximately within said working area and combining to cover such area to an open position at one end of said frame with said panels in substantially side by side stacked relationship to provide access through said central area to such machine, said panels being supported at their opposite ends by lazy tong mechanisms to permit such movement, said frame being formed in its opposite vertically extending marginal portions with longitudinally extending slots for receiving therein the central pivots of said lazy tong mechanism.

2. A guard according to claim 1 wherein locking means is provided for positively holding said panels in closed position.

3. A guard according to claim 1 wherein movement of said panels is controlled by a parallel motion mechanism to insure pure translation of said panels.

4. A guard according to claim 1 wherein a counterweight is employed to facilitate movement of said panels upwardly to open position.

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