RU2086497C1 - Sack gripper - Google Patents

Abstract

FIELD: materials handling facilities; load-gripping devices for sacks with loose materials. SUBSTANCE: sack gripper has sides, fixed and movable clamping stepped strips, with larger step in central portion and working surface over entire length, arranged parallel to each other and installed in recesses of sides, pins connecting clamping stepped strips, thrust member coupled with sides and clamping device in form of screw with heel arranged in threaded hole of thrust member made in form of plate. Heel is secured on one end of screw, and clamping handle is mounted on other end of screw. EFFECT: enlarged operating capabilities. 2 cl, 6 dwg

Description

 The invention relates to material handling equipment, in particular to gripping devices for bags with bulk materials when consuming material in a small amount.

 Known grip for bags containing sidewalls made with recesses and holes, fixed and movable clamping step strips with a larger step in the central part, made with a working surface along the entire length, parallel to each other and installed in the recesses of the sidewalls, fingers connecting the clamping step straps located on the fingers of the spring, a suspension bracket for connection with a lifting mechanism connected to the sidewalls, a clamping handle, an abutment element associated with the sidewalls, and a clamping device whipping associated with a thrust element.

 The known device is not reliable enough.

 The technical result of the proposed device is to increase reliability.

 The specified technical result is achieved by the fact that in the grip for bags containing sidewalls made with recesses and holes, the fixed and movable clamping step strips with a larger step in the central part, made with a working surface along the entire length, parallel to each other and installed in recesses sidewalls, fingers connecting clamping step strips located on the fingers of the spring, a suspension bracket for connecting with a lifting mechanism connected to the sidewalls, a clamping handle, a thrust element nt associated with the sidewalls and the clamping device associated with the stop element, the working surface of one of the clamping step strips along the entire length has a protrusion, and the working surface of the other clamp strip along the entire length of the cavity corresponding to the configuration of the protrusion, the stop element is a rigid installed in the holes of the sidewalls and made with a threaded hole, and the clamping device is a screw located in the threaded hole of the bar with a fifth fixed on one end of the screw on the other end of which is attached to the clamping handle.

 Also, the heel of the screw mounted on it movably.

 In FIG. 1 shows a gripper for bags in a working position; in FIG. 2 - the same, top view; in FIG. 3 section AA. in FIG. one; in FIG. 4 section BB in FIG. 2; in FIG. 5 and 6 diagram for calculating the reliability of holding the bag by the grip.

 The grip turns off two sidewalls 1 with round holes 2 in the upper part for hanging on the suspension of the lifting mechanism and recess 3, in which are mounted a stepped fixed bar 4 and a movable bar 5 (L bag width), with large steps in the middle, one of which has a protrusion 6 over the entire working surface, and the second corresponding to the configuration of the protrusion of the cavity, and in smaller steps 7 along the edges with holes for the fingers 8, on which the springs 9 are worn; washers 10 and cotter pins 11 to hold the strap 5 on the fingers; rigidly fixed in the rectangular holes 12 of the sidewalls 1, an abutment plate 13 having a threaded hole in the center through which a screw 14 passes, having a handle 15 on one side and a heel 16 freely mounted on the flared shaft of the screw.

 The device operates as follows.

 The grip suspended from the opening 2 in the sidewall 1 on the lifting mechanism is mounted on the bag so that the end edge of the bag, not occupied by the material, is between the protrusion and the depression of the strips 4 and 5, then the screw 14 is turned by the handle 15 so that its heel 16 comes In contact with the movable strap 5, she pushed it on the fingers 8 with the fixed strap 4, introducing the protrusion of one of them into the cavity of the other and squeezing the entire end edge of the bag between them. In this case, the springs 9 are compressed. The screw with the fifth can be turned with one hand, and the second hold the grip on the bag, preventing it from moving.

 To release the bag, the handle 15 is turned in the opposite direction, the clamping screw 14 with the fifth 16 are moved from the strap 5, and the springs 9 return the latter to its original position, freeing the bag.

 To accelerate the movement of the clamp screw along its axis, it is necessary to use a thread with a large pitch (for example, rectangular).

A diagram for calculating bag retention reliability is shown in FIG. 5, 6, where
N is the pressure force between the working grips; the pressure force on the clamping screw is N, but opposite in direction;
G weight of the transported bag;
f _Tr the friction force arising between the fabric of the bag and the working straps when they are compressed;
F is the force exerted on the handle of the clamping screw when compressing the end edge of the bag between the straps;
f $\genfrac{}{}{0ex}{}{\text{R}}{\text{tr}}$ the friction force arising in the threaded connection of the clamping screw and the threaded hole of the retaining plate during compression of the end edge of the bag;
l and r, respectively, the shoulders on which the forces F and f act $\genfrac{}{}{0ex}{}{\text{h}}{\text{tr}}$ .

Условие, при котором можно провернуть рукоятку зажимного винта, определяем по формуле:
F•l > f $\genfrac{}{}{0ex}{}{\text{р}}{\text{тр}}$ •r
Так как f $\genfrac{}{}{0ex}{}{\text{h}}{\text{тр}}$ =N•μ_р (где μ_р коэффициент трения в резьбовом соединении), то F•l > N•μ_р•r
Учитывая выражение (1), получаем:

Известно, что коэффициент трения между тканью и металлом заметно больше, чем между металлическим поверхностями.The condition under which the bag, sandwiched between the working strips of the grip, will be kept on weight, is determined by the formula:
f _tr ≥ G
Since f _Tr = N • μ (where μ is the coefficient of friction between the bag material and the metal strips), then N • μ ≥ G or

The condition under which the handle of the clamping screw can be turned is determined by the formula:
F • l> f $\genfrac{}{}{0ex}{}{\text{R}}{\text{tr}}$ • r
Since f $\genfrac{}{}{0ex}{}{\text{h}}{\text{tr}}$ = N • μ _r (where μ _{r is} the friction coefficient in the threaded connection), then F • l> N • μ _r • r
Given the expression (1), we obtain:

It is known that the coefficient of friction between fabric and metal is noticeably greater than between metal surfaces.

Принимаем:
1) G 70 к (наибольший вес мешков);
2) l 200 мм (приблизительно половина ширины мешка);
3) r 10 мм (при диаметре зажимного винта 20 мм)
Отсюда получим F 3,5 кг
Учитывая, что рабочий в подобных условиях создает минимальное усилие около 30 кг, т.е. на порядок больше, чем усилие, полученное при расчете, следовательно, предлагаемая конструкция захвата обеспечивает надежное удержание мешка.Conditionally considering them equal, which obviously increases F, we obtain from (2) the equation:

Accept:
1) G 70 k (the largest weight of the bags);
2) l 200 mm (approximately half the width of the bag);
3) r 10 mm (with a clamp screw diameter of 20 mm)
From here we get F 3.5 kg
Given that the worker in such conditions creates a minimum force of about 30 kg, i.e. an order of magnitude greater than the force obtained in the calculation, therefore, the proposed gripper design provides reliable retention of the bag.

Claims (2)

 1. Grip for bags containing sidewalls made with recesses and holes, fixed and movable clamping step strips with a larger step in the central part, made with a working surface along the entire length, parallel to each other and installed in the recesses of the sidewalls, fingers connecting clamping step strips located on the fingers of the spring, a suspension for connection with a lifting mechanism connected to the sidewalls, a clamping handle, an abutment element associated with the sidewalls, and a clamping device, associated with the stop element, characterized in that the working surface of one of the clamping step strips along the entire length has a protrusion, and the working surface of the other clamp strip along the entire length of the depression corresponding to the configuration of the protrusion, the stop element is a bar rigidly mounted in the holes of the sidewalls and made with a threaded hole, and the clamping device is a screw located in the threaded hole of the bar with a fifth fixed on one end of the screw, on the other end of which is fixed clamping handle.  2. The capture according to claim 1, characterized in that the heel of the screw is mounted on it movably.

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