., ; T]lis invent~on relates to a paperboard carton blank ar~ n~ore particu]arly ~o such a blank with a product registering tab for cartoning on a horizontal top loading pacXa~ing machine. There axe three basic cartoning methods. The first method is top loading of product into partially erected cartons. This is accomplished by folding up and sealing the front, back and side panels of a carton blank to form an open top box, load- ing the product in from the top, and then closin~ and sealing the top The second approach is to end Load the product into pre-glued carton sleeves. A sleeve style carton is one in which th~ blank manufacturer ma~es the flat carton b]ank inLo a sleeve ; before shipping it by sealing the side seam of the carton, more generally known in the art as a manufacturer's glue seam. The packager then erects the carton sleeves, loads the product into the open-ended sleeve, and finally completes the package by closing and sealing the end flaps. The third cartoning system a~nd the one to which this carton invention pertains is horizontal top loading (NTL). The .. . . HTL concept involves wrapping the carton blank around the product. - The HTL machine feeds in a flat carton blank when product is present. The product is placed on the bottom panel of the flat blank which is then wrapped around the product and the side seam sealed. The loaded carton sleeve is then grasped by top clamps, turned 90, and carried through the end sealing stations to com- plete the package. ` A problern with HTL systems has been to maintain the product in proper registration on the flat carton blank as the blank initially progresses through the HTL packaging machine. . . . The rapid movement of the flat blank through the machine tends to cause the product placed thereon to shift rearwardly on the blank which then subsequently interferes with the proper closing '' '~-`6 1 -- , ' :'.: - -'- . ` ':' ' ' : ,. : `~ 5 o~ tne end panels of the carton. Accordi.ng to the present invention there is provided a paperboard carcon blank comprising a hingedly connected rectan- gular bottom, top, front and back panels, a pair of leading and top an~ bottom end flaps hingedly connected along a first score line recpectlvely t.o said top and bottom panels, a pair of trail- ing top and bottom end flaps hingedly connected along a second score line respectively to said top and bottom panels, said trail ing hottom end f].ap comprising a pair of laterally spaced side ~: 10 portions, and a trailing edge product registering tab hingedly conneeted along said second score line to said bottom panel bet- ween the side porti.ons comprising said trailing bottom end f~.ap. ~ 3 The paperboard carton blank of this invention has a ; trailing edge product registering tab particularly suited for use in con~unction with HTL packaging machines. The trailing edye product registering tab is formed between the side portions of . . -the trailing bottom end flap to allow a bottom pusher lug of the packaging machine to engage the tab to prevent the product from slipping back on the blank a sufficient distance to prevent proper closing. In one version, where the product registerlny tab is of substantially the same height as the adjacent side portions of the trailing bottom end flap, the tab is separated from these side portions by a eut-line or notch and is folded up and held. against the trailing end of the produet by the pusher lug of the . . . paekaging machine to prevent the product. from slippiny rearwardly on the blank. , The present lnvention will be furt.her illustrated by - way of the accompanying drawings in which: . .. 30 Figure 1 is a plan vie~ of the ins;.de surface of a ~-~ carton blank embodying the principles of this invention. Figure 2 is a fragmentary plan view of the inside _ . . , : . : .. : .: .: ~ ` ` ` 1~)69~9~;; . ~ . `~ surface of a ~o~tion of another embodiment of a carton blank em~odyin~3 the principles of this invention; Fi~ure 3 is an isometric view of product on the carton blank of Figure 1 with a machine pusher lug~ (in phantom) encJag- ing'the ~ood product registering tab; and Figure 4 is an isometric view (partially in phantom~ showing ~he sealed package formed from the carton blank shown in Figures 1 and 3. Referring more particularly to the drawin~s wherein li~e numerals refer to like parts throughout the several views, the paperhoard blank, as shown in Figure 1, is suitably cut and scored to provide the carton generally referred to at 11 in Figure 4. The blank 10 has rectangular top panel ]2, bottom panel 13, front panel 14, back panel 15, and front glue flap 16, all hingedly connected in the well known manner show~. The -~ blank may have a product viewing window in the top panel such as is shown at 17. The particular carton blank shown could be used for packaging a product such as sliced bacon or the like. The product such as bacon 1~ shown in Figure 3 may or may not be in a separate sealed plastic pouch. The movement of the blank through the HTL machine (not shown~ is in the direction of the ~ arrow in Figure 3. ; Referring again to Figure 1, the carton blank 10 also.-. . . has a pair of leading top and bottom end flaps 19 and 20 hingedly connected a]ong a score line 21 respectively to top and bottom panels 12 and~13. The blank also has a pair of trailing top and bottom elld flaps 22 and 23 hingedly connected along a second score line 24 respectively to top and bottom panels 12 and 13. The ~railing bottom end flap is comprised of a pair of laterally spaced side portions-23a and 23b. A trailing edge product reg- istering tab 25 is hingedly connected along score line 24 to bottom panel 12 between the side portions 23a and 23b of the . ~, . ' ,.~ . ,, . , . ~ . . . . - . ~ . . : : . - '? `, ~ ~ ~i 9 ~ 9 5 ``' .. tra.i1ing bottom end flap. Irhe trailing edge product registra- ,. tion tab 25 i.s separated from both of the side portions 23a and 23b of the trailing bottom end flap by a pair of cut-out notches 26 and 27 which extend to score line 24. The blank 10 has a pair of leading dust flaps 28 and 29 hingedly connected along score line 21 respectively to front and back panels 14 and 15 and also has a pair of trailing dust flaps hingedly connected along score line 24 to front and back panels 14 and 15. The dust flaps which form the corners of the carton are folded in ` 10 before the end flaps are folded up. ~ As shown in,Figure 2, in a second embodiment a trail- : ing edge product registering tab 32 may be separated from the . '~ . side'portions of 33a and 33b of the trailing bottom end flap by cut lines or sl.its 34 and 35 rather than notches as shown in Figure 1. The cut-out notches 26 and 27 on blank 10 allow for .' better clearance of the product registering tab 25 with side por- ,~ tions 23aand 23b than the cut-line or slits 34 and 35 in the embodiment sllown in Figure 2. However, this second embodiment provides some~hat more package strength because the edges of 2o tab 32 directly abut the adjacent edges of said portion 23a and 23b in the sealed carton. ^i ~eferring now to ~lgure 3, the IiTL packaging machine (not shown~ feeds the flat carton blank 10 i.n the direction of. the arrow when product is pre'sent. The product shown, bacon 18, is placed on the bo-ttom panel of the flat blank. The packaging machine has a bottom pusher lug, shown in phantom at 36, which ; folds the product registration tab 25 upwardly and holds it '~ against the t.ra;.ling end of the product 18 thereby preventing ; the product from sli.pping rearwardly on the blank as it ~oves through the pac~aging machine for completion. ; . The completed carton 11 is shown in Figure 4 with the underl.ying product registration tab 25 shown in phantom. ' .,~''`~ . .