Strap path access means for a strapping machine

Abstract: A strapping machine includes a pivotal strap path access cover (1) with an integral feed wheel (4) mechanism. The strap path access cover (1) is pivotable, without the use of tools, to an open inspection position, such that the feed wheel (4) integral with the access cover (1) is also moved clear of the inspection area, allowing unhampered access to the inspection area for removal of strap debris or correction of various malfunctions.

Description: Strapping machines are prone to strap jamming, misfeeding, and other problems. The present invention concerns providing access to enable such difficulties to be rectified without the need for removal of fasteners, or separation of elements from the body of the strapping machine. In the past, strapping machines as described in document US-A-5 442 899, for example, have required detachable strap guides and access covers to allow service access to problem areas of the strapping machines. Access to certain areas of the strapping machine is important because of normally encountered problems such as strap jamming, misfeeding, and excess accumulation of strap debris. In particular, access to areas near the feed and tensioning wheels and direction changing strap guides is critical because of the generally close space tolerances at these points. Prior art strapping machines required detachable elements for providing the necessary access. However, the temporary detachment of elements from the strapping machine presents several problems. Tools are usually required to remove and install the necessary fasteners on the detached elements. Detached elements, such as access covers and guides, are subjected to the increased threat of damage or loss as a result of being separated from the strapping machine. Those prior art strapping machines which allow for removal of elements without tools provide for only limited access to the necessary areas. According to this invention a strapping machine includes a main access cover pivotally mounted on its frame, a first feeding means mounted on the main access cover, and a latching means, wherein upon unlatching the latching means, the main access cover and first feed means are pivotable from a closed operating position to an open access position, thereby allowing access to a strap path through the machine without the detachment of any element from it. Such a strapping machine provides convenient access to the strap path of the feed and tensioning mechanism. The pivotable strap path cover is held in place and is also releasable via a latching mechanism which requires no tools for operation. A particular embodiment of a strapping machine in accordance with this invention will now be described with reference to the accompanying drawings; in which:- Figure 1 is a top front perspective view; Figure 2 is a top back perspective view; and Figure 3 is a front view. As shown in Figure 1, the present invention discloses a main access cover 1 pivotally mounted to a frame of a strapping machine. In one embodiment, the main access cover 1 is hinged at two points adjacent a lower edge of the cover. At a point distal the hinged edge, the cover 1 eliminates in a curved access cover guide 18. The guide 18 in one embodiment directs the strap around a first tension wheel 12. In one embodiment, the invention may include a first tension wheel 12 and a second tension wheel 13 having parallel central access, tension wheels 12 and 13 being fixed to the frame of the strapping machine and located at a point above the feed wheels. Second feed wheel 8 may be fixed to the frame and located directly below second tension wheel 13. First feed wheel 4 is attached to and rotatable within the main access cover 1 about a feed wheel lever shaft 6. A feed wheel lever 5 is pivotally attached to the main access cover 1, the feed wheel lever 5 being spring biased in a direction which angles the first feed wheel 4 against the strap in a manner which firmly presses the strap against the opposing second feed wheel 8. A spring loaded latch 9 is mounted on the main access cover 1. When the main access cover 1 is in the upright, closed, operating position, the latch 9 secures the main access cover in this position. Upon applying an external force to the latch handle 17, the latch 9 is moved out of the locked position, allowing the main access cover to be pivoted down into the open position. Pulling open the latch handle 17 also acts against the spring biasing the first feed wheel 4 against the strap, moving the first feed wheel 4 away from the strap and opposing second feed wheel 8, thereby creating sufficient clearance between the first feed wheel 4 and the strap and other elements to facilitate opening and closing of the main access covers. In one embodiment, the main access cover 1 is formed such that during operation in the closed position, only a small segment of the first feed wheel 4 circumferential surface is exposed to the strap, via a slot which is present in the main access cover 1. The slot may be formed in a feed wheel receiving block 22. The circumferential surface of the first feed wheel 4 is withdrawn from the slot upon pulling open the lateral handle 17. A pivotable actuation lever 11 having a cammed surface 14 may be used to control the position of the first feed wheel 4 and the first tension wheel 12. Before the strapping machine enters the strap feed mode, the cammed surface of the pivotable actuation lever 11 holds the first feed wheel 14 away from the strap, until the strap feed mode begins. The cammed surface 14 may ride along a roller surface 19 when the main access cover 1 is in the closed, operating position. Referring now to Figure 3, the actuation lever 11 may be strategically positioned by the action of the strapping machine main space cam against the main cam roller 20. As the actuation lever is urged by the main space cam, the actuation lever cam surface 14 acts against the roller surface 19, thereby urging the first feed wheel actuation lever 21 against the feed wheel lever 5 to alternately engage and disengage the first feed wheel 4 with the strap. Referring now to Figures 2 and 3, upper access cover 2 is spring biased to open when the main access cover 1 is in the open position. When in the closed, operating position, the upper access cover 2 provides a guide path for the strap downstream of the first tension wheel 12. In operation, the pivotable main access cover 1 with the integrated first feed is wheel 4 allows for unrestricted access to the critical areas between the feed wheels and between the tensioning wheels, greatly facilitating the ability of an operator to clear debris and correct strap misfeeds in this area. Because the operation of cleaning and troubleshooting this area is made simple, while maintaining and enhancing the performance of the normal feeding and tensioning modes, the overall performance of any strapping machine incorporating these features will be greatly enhanced.

Claims: A strapping machine including: a main access cover (1) pivotally mounted on its frame, a first feeding means (4) mounted on the main access cover (1), and a latching means (9), wherein upon unlatching the latching means (9), the main access cover (1) and first feeding means are pivotable from a closed operating position to an open access position, thereby allowing access to a strap path through the machine without the detachment of any element from it. A strapping machine according to Claim 1, further comprising a feed wheel lever means (5) pivotally mounted on the main access cover (1), the first feeding means (4) being rotatably attached to the feed wheel lever means (5), the feed wheel lever means (5) being biased to urge the first feeding (4) means against a strap during a feeding mode of the strapping machine. A strapping machine according to claim 1 or 2, further comprising a feed wheel receiving block, wherein the first feeding means comprises a first feed wheel (4) which partially extends through a slot in the feed wheel receiving block when the main access cover (1) is in the closed operating position, and is retracted from the slot when the main access cover (1) is opened. A strapping machine according to any one of the preceding claims, further comprising hinge points disposed at a lower edge of the main access cover (1), and an access cover strap guide (18) disposed at a distal end of the main access cover (1). A strapping machine according to any one of the preceding claims, further comprising a first and a second tension wheel (12,13) disposed adjacent a top portion of the main access cover (1), a second feeding means, including a feed wheel (8) disposed adjacent a bottom portion of the main access cover (11), and a feed wheel pressure adjuster (16), wherein pressure exerted by a first feed wheel (4) against a strap fed between the first and second feed wheels (4,8) is held at a selected pressure level by the feed wheel pressure adjuster (16). A strapping machine according to any one of the preceding claims, further comprising an upper access cover (2) which cooperates with an actuator lever (11), the actuator lever having a main cam roller (20) which is acted upon by a main cam, wherein the upper access cover (12) is moved to an open position upon opening of the main access cover (1). A strapping machine according to claim 6, further comprising an actuation lever cam surface (14) disposed at a bottom portion of the actuation lever (11), a first feed wheel actuation lever (21) acting in cooperation with the feed wheel lever (5), and a roller surface (19) which cooperates with the actuation lever cam surface (14), wherein the main cam (20) acts upon the actuation lever (11) which cooperates via its actuation lever cam surface (14) with the roller surface (9) and first feed wheel actuator lever (21) to hold the first feed wheel (4) at a distance from the strap until the strapping machine enters the strap feed mode.

Inventors: BELL LEM, HABERSTROH JAMES, PEARSON TIM, BELL, LEM, HABERSTROH, JAMES, PEARSON, TIM
Applicants: ILLINOIS TOOL WORKS, ILLINOIS TOOL WORKS INC.
Application year: 1996
Main classification: B65B13
IPC codes: B65B13, B65B59