Hand strapping tool

Abstract: A hand strapping tool (110) has a two-piece outer link (122) assembly wherein a first upper outer link member (122U) is mounted upon a pivot shaft (136) of the tool, while a second lower outer link member (122L) is mounted upon the distal end portion of the feedwheel shaft (116) so as to maintain the feedwheel (118) upon the feedwheel shaft (116). The second lower outer link member (122L) is removably fastened to the first upper outer link member (122U) by suitable fasteners (152) whereby when the feedwheel (118) is to be replaced as a result of, for example, wear thereof only the lower outer link member (122L) needs to be disconnected from the upper outer link member (122U) so as to provide access to the feedwheel (118).

Description: The present invention relates generally to hand strapping tools, and more particularly to a hand strapping tool wherein the feed wheel mounting structure within the tool facilitates and simplifies the replacement of the feed wheel when necessary due, for example, to normal wear of the wheel as a result of its use within such hand strapping tools under strap tensioning conditions. Hand strapping tools are conventionally used to apply strapping material, made of either plastic, steel, or similar materials, around various articles, packages, or loads. In operating such a conventional hand strapping tool, the feed wheel, which is an element or component of the tool tensioning unit, is driven by a suitable motor drive and serves to tension the strapping material to a predetermined amount of tension as determined by stalling of the motor when the predetermined amount of tension level is attained. Subsequently, the strapping is joined and severed and a new article, package, load, or the like is readied for a strapping operation. As a result of such multiple strapping operations involving such tensioning processes, feed wheels undergo wear and therefore need to be replaced. However, with conventional hand strapping tools, the replacement of the feed wheel is not especially convenient and is quite time-consuming as can be better appreciated as a result of reference being made to FIGURES 1 and 2 of the drawings. FIGURES 1 and 2 disclose a conventional hand strapping tool which is generally indicated by the reference character 10. Briefly, the hand strapping tool 10 comprises a tension unit 12 which includes a motor drive, not shown, and a gearbox 14 operatively connected to the tension unit motor drive. An output feedwheel shaft 16 projects laterally outwardly from one side of the gearbox portion 14 of the tension unit 12, and a portion of the external periphery of the feedwheel shaft 16 has a hexagonal configuration. A feedwheel 18, having a complementary internal hexagonal peripheral surface, is adapted to be mounted upon the feed-wheel shaft 16 so as to be driven by the feedwheel shaft 16 as a result of the driving force generated by the tension unit motor drive and transmitted by the gearbox 14. The feedwheel shaft 16 passes through an aperture 19 of a breaker foot 20, and the feedwheel 18 is maintained upon the outer or distal end of the feedwheel shaft 16 by means of an outer link 22, the outer link 22 also being provided with an aperture 23 through which the free or distal end of the feedwheel shaft 16 passes. The outer link 22 is in turn mounted upon a position link 24 by means of a pin 26, wherein the position link 24 and pin 26 comprise a subassembly. Position link 24 is mounted upon a support rod 28 through means of another pin 30. A hanger rod 32, as shown in FIGURE 2, has casting flanges or mounting brackets 34, only one of which is shown in FIGURE 2, mounted thereon upon respective opposite sides of the tool. The tension unit 12, the feedwheel assembly comprising the feedwheel shaft 16 and the feedwheel 18, and the outer link 22 are mounted upon casting flanges 34 through means of a pivot shaft 36 and a nut 38. The pivot shaft 36 and nut 38 permit the tension unit 12, the feedwheel assembly comprising the feedwheel shaft 16 and the feedwheel 18, and the outer link 22 to be pivotally movable between operative and inoperative positions with respect to upper and lower straps which are to be tensioned and joined together and which are shown at 42 and 44 respectively. The pivot shaft 36 is seen to extend or pass through apertures 37,39, 41, and 43 respectively provided within the casting flange 34, outer link 22, breaker foot 20, and the gearbox portion 14 of the tension unit 12. The motor drive of the tension unit 12 is activated by means of a manual trigger lever 40. It can thus be appreciated that when the feedwheel 18 needs to be replaced, the pivot shaft 36 must first be removed from the tool 10 whereby the entire tension unit assembly comprising the tension unit 12, the feedwheel shaft 16 and feedwheel 18, and the outer link 22 are disengaged and able to be removed from the casting flanges 34. The outer link 22 and the pin 26 must then be removed as a subassembly from the position link 24 whereby access to the feedwheel 18 upon the feedwheel shaft 16 is then achieved such that the worn feedwheel 18 can now be replaced. Once the new feedwheel has been placed upon the feedwheel shaft 16, the reverse procedures concerning the disposition or mounting of the outer link 22 and pin 26 upon the position link 24, as well as the disposition or mounting of the entire tension unit assembly upon the casting flanges 34 by means of the pivot shaft 36, must then be performed. It can therefore be appreciated that replacement procedures with respect to the feedwheel 18, comprising the disassembly of the tool component parts, and the re-assembly of such parts, as noted hereinabove, can be quite time-consuming. A similar hand strapping tool in accordance with the preamble of claim 1 is disclosed in US-A-3028885. A need therefore exists in the art for a hand strapping tool wherein the structural assembly of the tension unit, and in particular, the mounting of the feedwheel thereon, is such that replacement of the feedwheel as necessary due to wear or other conditions, is considerably simplified in order to render the replacement procedure for the feedwheel relatively easy, straightforward, and quick with minimum production downtime. According to this invention in a hand strapping tool as defined in claim 1 the mounting structure for the feedwheel assembly comprises a two-part or two-piece outer link comprising an upper outer link member and a lower outer link member. The upper outer link member is mounted upon the pivot shaft in a manner similar to the outer link members of the existing or conventional hand strapping tools, whereas the lower link member is disposed upon the outer or distal end of the feedwheel shaft so as to maintain the feedwheel mounted upon the feedwheel shaft. The lower link member is fixedly secured to the upper link member by means of two bolt or threaded fasteners. Accordingly, when the feedwheel needs to be replaced, the two bolt or threaded fasteners are simply removed from the outer link assembly comprising the upper outer link member and the lower outer link member whereby the lower outer link member is now able to be removed from the upper outer link member as well as from the outer or distal end of the feedwheel shaft thereby exposing or providing access to the feedwheel which may now be replaced. When the feedwheel is replaced, the lower outer link member is simply replaced upon the outer or distal end of the feedwheel shaft, and the two bolt or threaded fasteners are reinserted so as to fixedly mount the lower outer link member upon the upper outer link member and thereby maintain the lower outer link member upon the feedwheel shaft so as to in turn maintain the feedwheel upon the feedwheel shaft. A particular embodiment in accordance with this invention will now be described with reference to the accompanying drawings; in which:- FIGURE 1 is an exploded perspective view of some of the component parts comprising a conventionally existing PRIOR ART hand strapping tool; FIGURE 2 is a partial perspective view showing the hand strapping tool of FIGURE 1 in its assembled state; FIGURE 3 is a partial perspective view similar to that of FIGURE 2 a hand strapping tool in accordance with the present invention; FIGURE 4 is a front elevational view of the upper outer link component; FIGURE 5 is a side elevational view of the upper outer link component; FIGURE 6 is a front elevational view of the lower outer link component; and FIGURE 7 is a side elevational view of the lower outer link component. Referring now to the drawings, and more particularly to FIGURE 3 thereof, the new and improved hand strapping tool constructed in accordance with the teachings and principles of the present invention is disclosed and is generally indicated by the reference character 110, while FIGURES 4-7 disclose the details of the new and improved upper and lower outer link components which comprise the essential component parts of the new and improved feedwheel mounting system incorporated within the tool 110. It is also noted that the hand strapping tool 110 disclosed within FIGURE 3 is essentially the same as that disclosed within FIGURE 2, except as will be specifically noted hereinafter, and therefore those parts of the tool 110 which correspond to similar parts of the tool 10 disclosed within FIGURE 2 are designated by similar reference characters except that the reference characters of the parts of the tool 110 as disclosed within FIGURE 3 are in the 100 series. Referring then to FIGURE 3, it is briefly seen that the hand strapping tool 110 comprises the tension unit 112 which has the gearbox 114 operatively associated therewith. The feedwheel 118 is mounted upon the feedwheel shaft 116, and the pivot shaft is shown at 136. However, it is critically noted that in lieu of the single outer link component or member 22 which mounts the tension unit 12 upon the pivot shaft 36 as disclosed in accordance with the structural arrangement of the PRIOR ART hand strapping tool 10 disclosed in FIGURES 1 and 2, there is provided a two part or two-piece outer link sub-assembly which comprises an upper outer link member 122U and a lower outer link member 122L. More particularly, with additional reference also being made to FIGURE 4, it is seen that the upper outer link member 122U is provided with an aperture 139 through which the pivot shaft 136 is inserted so as to mount the upper outer link member 122U, as well as the breaker foot 120 and the gearbox portion 114 of the tension unit 112 upon the casting flange or mounting bracket 134. As can be further appreciated as a result of additional reference being made to FIGURE 5, the lower portion of the upper outer link member 122U also comprises a dependent flanged portion 146 which is set back rearwardly with respect to the front face of the upper outer link member 122U and within which a pair of apertures 148, 148 are provided. With additional reference being made to FIGURES 6 and 7, it is seen that the lower outer link member 122L is provided with an aperture 123 through which the free or distal end portion of feedwheel shaft 116 is disposed, and the upper portion of the lower outer link member 122L is provided with an upstanding flanged portion 150 which is disposed forwardly with respect to the rear face of the lower outer link member 122L and within which a pair of apertures 152,152 are provided. The flanged portions 146 and 150 of the upper and lower outer link members 122U,122L, respectively, comprise complementary structural configurations such that the upper and lower outer link members 122U,122L, can be fixedly fastened together when the flanged portions 146 and 150 thereof are disposed in an abutting overlapping disposition with respect to each other ana suitable bolt or threaded fasteners 154,154, as shown in FIGURE 3, are inserted through the sets of apertures 148 and 152. With particular reference lastly being made to FIGURE 3, it can therefore be readily appreciated that as a result of the particular structural arrangement developed in accordance with the teachings and principles of the present invention by means of which there is provided the two-piece or two-part outer link assembly comprising the upper outer link member 122U and the lower outer link member 122L for mounting and maintaining the disposition of the feedwheel 118 upon the hand strapping tool 110, when the feedwheel 118 is to be replaced, such procedure is simply and quickly accomplished by simply removing the lower outer link member 122L from the upper outer link member 122U as a result of removing the fasteners 154,154. The lower outer link member 122L may then be simply removed from the free or distal end portion of the feedwheel shaft 116, and the feedwheel 118 may then be similarly removed and replaced with a new feedwheel. The lower outer link member 122L may then be simply remounted upon the upper outer link member 122U as a result of reinserting the fasteners 154,154. Thus, the pivot shaft 136 need not be removed from the tool assembly, and similarly, the entire tension unit assembly, including the upper outer link member 122U, need not be removed from the tool assembly, that is, for example, from the casting flanges 134,134 as well as from the position link 124. Thus, it may be seen that as a result of the aforenoted structural arrangement or system, replacement of the feedwheel is readily simplified, is able to be accomplished quickly and easily, and production downtime is minimized. In addition, by replacing conventional one-piece outer link members, currently in position and in use upon conventional PRIOR ART hand strapping tools, with the new and improved two-piece or two-part outer link structural system, such conventional PRIOR ART hand strapping tools may be readily retrofitted so as to substantially improve the utility and service of such tools from a production point of view.

Claims: A hand strapping tool (110), comprising: a mounting bracket (134); a tension unit (112); a feedwheel shaft (116) operatively connected at a first proximal end portion thereof to said tension unit (112), and having a second distal end portion; a feedwheel (118) mounted upon said feedwheel shaft (116); a pivot shaft (136) for pivotally mounting said tension unit upon said mounting bracket (134); an outer link (122) mounted upon said pivot shaft (136) and mounted upon said distal end portion of said feedwheel shaft (116); and characterized in that said outer link comprises a first outer link member (122U) mounted upon said pivot shaft (136), and a second outer link member (122L) mounted upon said distal end portion of said feedwheel shaft (116) and removably fastened to said first outer link member (112U), whereby when said feedwheel (118) is to be removed from said feedwheel shaft (116), only said second outer link member (122L) need be disconnected from said first outer link member (122U). A hand strapping tool according to claim 1, wherein said first outer link (122U) is formed by an upper link, and said second outer link (122L) is formed by a lower link. A hand strapping tool according to Claim 1 or 2, wherein: said first outer link member (122U) includes a dependent flanged portion (146); and, said second outer link member (122L) includes an upstanding flanged portion (150) complementary to said dependent flanged portion (146) of said first outer link member (122U). A hand strapping tool according to Claim 3, wherein: said first outer link member (122U) comprises a first pair of apertures (148) defined within said dependent flanged portion (146) for receiving fasteners for fastening said first and second outer link members together; and, said second outer link member (122L) comprises a second pair of apertures (152) defined within said upstanding flanged portion (150) for receiving the fasteners for fastening said first and second outer link members together. A hand strapping tool according to claim 3 or 4, wherein: said first outer link member (122U) has a front surface, and said first dependent flanged portion (146) of said first outer link member is set back rearwardly from said front surface of said first outer link member; and, said second outer link member (122L) has a rear surface, and said second upstanding flanged portion (150) of said second outer link member is disposed forwardly from said rear surface of said second outer link member. A hand strapping tool according to any one of the preceding claims, further comprising: fastener means (154) for fixedly fastening said second outer link member (122L) to said first outer link member (122U).

Inventors: CHEUNG NELSON, CHEUNG, NELSON
Applicants: ILLINOIS TOOL WORKS, ILLINOIS TOOL WORKS INC.
Application year: 2000
Main classification: B65B13
IPC codes: B65B67, B65B13, B65B59