US2721018A - Bagpacker with serially releasable, two-part bag gripping means - Google Patents

Description

Oct. 18, 1955 J HEAVIN 2,721,018

L. BAGPACKER WITH SERIALLY RELEASABLE, TWO-PART BAG GRIPPING MEANS Filed Jan. 20, 1955 5 Sheets-Sheet l Oct. 18, 1955 J. HEAVIN 2,

BAGPACKER WITH SERIALLY RELEASABLE, TWO-PART BAG GRIPPING MEANS Filed Jan. 20, 1955 5 Sheets-Sheet 2 1955 L. J. HEAVIN BAGPACKER WITH SERIAL 2,721,018 LY RELEASABLE, TWO-PART BAG GRIPPING MEANS 5 Sheets-Sheet 3 Filed Jan. 20, 1955 L. J. HEAVIN Oct. 18, 1955 2,721,018 BAGPACKER WITH SERIALLY RELEASABLE, TWO-PART BAG GRIPPING MEANS 5 Sheets-Sheet 4 Filed Jan. 20, 1955 @wza 73/ J @W 1 1955 J. HEAVIN 2,721,018

BAGPACKER WITH SERIALLY RELEASABLE, TWO-PART BAG GRIPPING MEANS Filed Jan. 20, 19 5 Sheets-Sheet 5 ,IJQ. 8.

five/z 07 eazzawdfieavaz United States Patent BAGPACKER WITH SERIALLY RELEASABLE, TWO-PART BAG GRIPPING MEANS Leonard J. Heavin, Orange, Tex.,

assignor to Spencer Chemical Company,

3 Claims. (Cl. 226-61) This invention relates to bag filling and closing machines of the turret-type as shown in the Allen et al. patents, Nos. 2,343,439, dated March 7, 1944, and 2,360,635, dated October 17, 1944, and the Briggs patent, No. 2,054,279, dated'September 15, 1936, and the patents referred to therein, and more particularly to that portion of such machines as has to do with the support and spacing of the bags during filling and closing.

Such machines comprise essentially a rotatable turret having grippers for supporting the bags during filling periods, and a bag-closing section arranged tangentially to the turret for closing and sewing the bag ends after filling. The turret assembly includes a plurality (usually eight or ten) of bag-filling spouts arranged vertically and projecting into the open bag ends manually placed thereon, which spouts can be charged from above, as they rotate, with the desired amount of material to be bagged. The bags are supported on the spout ends and thereafter by a forward fixed gripper at the leading end of each bag and a rear swingable gripper at the trailing end of each bag. After filling, the grippers and bag are lowered by cam means disclosed in the foregoing patents until the bag engages carrier chains. As the bag leaves the spout the spacing between the forward and trailing grippers is increased to close the end of the bag. As the bag leaves the turret assembly the forward gripper is first released, then the rear gripper is released, and the bag is moved to the bag-closing section which closes and sews the bag.

During the filling operation the bags on the turret are spaced about eight or nine inches apart, i. e., from the trailing bag edge of one bag to the leading bag edge of the succeeding bag when standard 18-inch bags are being filled. Such spacing is necessary to provide working space for the operators as well as the necessary mechanisms. However, during the sewing operations it is highly desirable to reduce this spacing to three or four inches so as to minimize the waste of tape and sewing thread, minimize entangling free ends, and get complete closure and maximum speed and production in the closing operation.

Attempts have been made to reduce this straightaway spacing of the bags. One such attempt was the introduction of a speed-change mechanism in the straightaway movement of the carrier chains as shown in the Allen et al. patent, No. 2,360,635. Such mechanisms are costly to build, operate and maintain. Another attempt involved running the carrier chain in the straightaway at a slower linear speed than the speed of the turret. This, however, resulted in crowding of the bags onto the carrier chains and consequent wrinkling of the bags, making passage thereof through the sewing head impossible. All past attempts caused undue crowding of the bags, raising of the trailing end of the bag and consequent wrinkling and even tearing the bag as it entered the carrier chains, making transportation through the sewing head impossible.

It is the purpose, therefore, of this invention to provide a simple, inexpensive means for reducing the turret spacing of the bags prior to sewing and one that is not only economical to build but also to operate and maintain without the above-mentioned drawbacks. The foregoing is accomplished by operating the carrier chain at a linear speed slightly less than the peripheral speed of the turret and by providing a trailing bag gripper that is movable in a substantially horizontal direction for a substantial distance opposite to that of the turret movement and so moving the trailing gripper as the bag is fed onto the bag carrier chains. This prevents crowding, wrinkling and tearing of the bags and in that sense compensates for the difference in speed between the turret and straightaway sections.

A better understanding of this invention will be had from the following description of a preferred embodiment of this invention, particularly when read in connection with the accompanying drawings in which:

Figure l is a plan view of a bag filling machine constructed according to this invention;

Figure 2 is a fragmentary side elevation of a hopper and bag-supporting means with the bag in filling position;

Figure 3 is a similar view with the bag filled and lowered to the rear end of the carrier chain with both grippers engaging the bag and holding the latter taut and the front gripper about to be released;

Figure 4 is a similar view with the bag farther along on the carrier chain and the front gripper released and the rear gripper holding the bag taut;

Figure 5 is a similar view with the bag still farther along on the conveyer chain and the rear gripper still holding the bag taut but about to be released by the release cam;

Figure 6 is a reverse fragmentary side elevation of a portion of the rear gripper;

Figure 7 is a horizontal sectional view taken along line 7-7 of Figure 6;

Figure 8 is a vertical sectional view 8-8 of Figure 6; and

Figure 9 is a sectional view taken along line 99 of Figure 8.

There is illustrated a turret-type bag filling and closing machine of the type shown in the prior patents mentioned and again referred to for details of construction not necessary to repeat here for a ready understanding of this invention. In the illustrated machine the continuously rotatable turretS has eight filling spouts 10 fed from above as they rotate, from any suitable hopper, with a weighed amount of material to be bagged. Any number of filling spouts can be used although most frequently eight or ten are employed. Bags B to be filled are placed on the spouts by an operator as the turret rotates by the loading station. Any suitable drive motor 6 for rotating the turret may be utilized as shown in the prior patents.

Each bag is grasped and supported by a forward fixed gripper indicated generally by the reference character and having automatically operable separable jaws and by a trailing gripper indicated generally at 20, also having separable jaws. The grippers are constructed and operated as disclosed in Patent No. 2,343,439. After being filled, the bags and grippers are lowered as shown in the heretofore mentioned patents, and the filled bag is fed onto the carrier chains arranged tangentially to the turret as is common in this type of machine. The carrier chains comprising the lower endless slat conveyer and the upper endless side chains 26 convey the filled bags to the bag-closing mechanisms including the stitching or sewing head 27 where the bag mouth is closed and stitched, through the tape-applying devices 28 where tape is applied over the stitching, and which devices taken along line 3 include press rolls and -shear devices where the sewing thread and tape are pressed and severed, and thence to the loading conveyers.

For further details of the foregoing mechanisms reference is made-to 'th' patents heretofore mentioned.

The problem of attaining proper bag spacing is accomplished without the use of'intricate and costly speedchanging mechanisms by operating the straightaway car riers 25 and 26 at a' constant speed having a linear travel somewhat less than the peripheral speed of the rotatory turret, preferably in the ratio of 111.23, and by causing the'trailing gripper 20 to support the bag in such a manner as to prevent crowding of the bags and consequent wrinkling and jamming and tearing of the bags otherwise caused by the differential in speed of the turret and straightaway conveyers. I e

As shown in Patent- No. 2,054,279, the leading and trailing grippers are supported from pivoted arms 30 (67 of the patent) which provides for vertical movement of both grippers permitting lowering of the bag from the filling spouts while remaining gripped. The

trailing gripper 20 is supported from bracket 32 bolted to an arm 30 and to which is bolted a. fixed pivot arm 34 extending vertically upward a substantial distance such as 19 inches and terminating in a boss 36 carrying a fixed pivot pin 38 upon which is journaled a swinging vertical radial arm 40. To the lower end of arm 40 is secured the trailing gripper housing 42 adjustably supporting the fixed gripper jaw 44. Cooperating withthe fixed jaw 44 is the separable jaw 46 pivoted to the housing 42 at 48 and movable toward the fixed jaw by a toggle link 50 and arm 52. The latter carries a roller 54 upon its free end engageable with a cam 56. The separable or retractable jaw is urged to either open or closed position by a spring 58.

Normally, the radial arm 40 and the trailing gripper are urged counterclockwise about pin 38 (Figs. 2, 3, 4 and by the stretch rod spring 60, as shown in Figure 2, to move the trailing gripper horizontally and toward the leading gripper. The leading gripper has a fixed jaw, and a retractable jaw under control of a toggle arm 52a and roller 54a, all operable in the same manner as the trailing gripper and releasable upon contact of roller 54a with cam 56.

The action of spring 60 is efiective only when the gripper assembly and bag are in raised position with the bag around the filling spout (Fig. 2). As the bag and gripper assembly are lowered, after the bag is filled, by cam action as disclosed in the aforementioned patents, the trailing gripper is urged in a horizontal direction away from the forward gripper, i. e., in a direction opposite to the movement of the bag as it is fed onto the carrier chains. This is accomplished by means of a weight 65, preferably approximately 25 pounds, adjustably secured to the free end of horizontal arm 66 attached at its other end to the swinging radial arm 40, thus urging the swinging arm and trailing gripper clockwise about pivot pin 38. Due to the long radius, i. e., distance between pin'38 and the jaws of the trailing gripper, the jaws move in a substantially horizontal direction with substantially no vertical movement tending to raise the gripped bag/ As the bag is lowered from the spout the bag is first stretched tight and closed (Fig. 3). Then as the bag progresses toward the carrier chains the forward gripper is released as its roller 54a engages cam 56 (Fig. 3'). However, the trailing gripper still holds and the weight and arm 66 continue to urge the trailing gripper in a direction opposite to that of the travel of the bag, thus keeping the upper edge of the bag closed and stretched free of wrinkles. The bag continues onto the carrier chains (Figs. 4 and 5) until finally the roller 54 of the trailing gripper engages cam 56 and the trailing gripper is released. Following this the bag progresses on through the bag-closing mechanisms, that is, through the stitching head and tape-applying mechanisms and then to the loading platform (not shown).

Due to the slight reduction in linear speed of the carrier chains of the straightaway with relation to the peripheral speed of the turret, the preferred ratio being 1:123, and the substantially horizontal movement of the trailing gripper, a compensating action is provided, that is, the trailing swingable gripper is urged back substantially horizontally about the pivot pin' 38 by the action of gravity on weight 65. Thus, the trailing swingable gripper moves backward a distance necessary to retain the bagtop taut and Wrinkle free while the bag spacing is reduced approximately five inches, i. e., from that on the turret to that desired in the straightaway, maintaining necessary tension on the bag top at all times to prevent wrinkling; The foregoing is accomplished without the use of complex and expensive gear speed-changing mechanisms or other intricate devices.

It is obvious that variations in details of construction 4 may be indulged in such as substituting springs for the weight 65 without departing from the spirit and scope of this invention as defined in the attached claims.

I claim: e

1. In a machine for filling and closing bags, a rotatable turret having means thereon for circumferentially supporting and filling said supported bags while being conveyed by said turret, and a traveling carrier arranged tan- 7 gentially to said turret to receive filled bags and convey.

them to suitable closing means at a linear speed slightly less than the peripheral speed of the turret, said supporting means comprising a gripper for engaging the leading upper edge of a bag during filling thereof, a gripper for engaging the trailing edge of a bag during filling thereof, means for releasing said grippers in sequence as the filled bag is received by said carrier, one of said grippers being movable prior to release in a substantially horizontal direction away from the other gripper to increase the distance between said grippers,'and means for so moving said movable gripper.

2. In a machine for filling and closing bags as defined in claim 1 wherein said movable gripper is the trailing gripper and is moved substantially horizontally in a direction opposite to the direction of travel of said bag when on said turret.

No references cited.

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