US 3556579 A
Description (OCR text may contain errors)
SUCTION PADS 2. Sheets-Sheet 1 Filed June 17, 1968 u Ill lIlLlIll |lllI i l l ll l II I ll llll, .lllll II II III lllll ll hlllllllllllllll a l llsllllll If!!! I lulllilllll |I|||||||I ngfime EH K. J. $EYMOUR-WALKER ETAL 3 55mm SUCTION mas Filed J1me 1.7, 1963 2 Sheets-Sheet 2 United States Patent Office 3,556,579 Patented Jan. 19, 1971 3,556,579 SUCTION PADS Kay John Seymour-Walker and David John Tudor Webb,
Garston, Watford, England, assignors to National Research Development Corporation, London, England, a corporation of Great Britain Filed June 17, 1968, Ser. No. 737,756 Int. Cl. 1366c 1/02 US. Cl. 294-65 5 Claims ABSTRACT OF THE DISCLOSURE There is described a suction pad having side portions depending downwardly from a top portion and adapted to be brought into gripping relationship with the side faces of an article to be lifted by the pad. In preferred embodiments the pad presents a lifting surface also to the top surface of the article.
The present invention relates to suction pads and in particular to suction pads for lifting uncured concrete articles.
Hitherto such articles have been lifted by suction pads arranged to apply a holding force only on the upper surface of the article. This method has the disadvantage that only one article may be lifted at a time so that considerable inconvenience is experienced where e.g. it is required to move a pile of concrete slabs from one location to another. Another disadvantage is that the known pad must necessarily engage the upper surface of the article for lifting and this face is often visible when the article is being put to use e.g. as a wall panel; thus in such cases, special precautions may be necessary to see that the pad does not spoil the appearance of the finished panel.
The present invention provides, for lifting an article having a top surface and side surfaces extending downwardly from said top surface, a suction pad comprising a top portion adapted to be located over the top surface of said article, side portions to said pad depending downwardly from said top portion, holding means carried on said side portions, said holding means being adapted to make sealing engagement with said side surfaces of said article during operation of the pad, and inlet means for connection of said pad with a vacuum source thereby to bring said holding means into gripping relationship with said side surfaces of said article.
In order that the invention may be more fully understood embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, of which:
FIG. 1 is a part vertical section of a first embodiment of the invention;
FIG. 2 is a detail of FIG. 1; and
FIG. '3 is a vertical section of a second embodiment of the invention in combination with a block splitting apparatus.
Thus referring first to FIGS. 1 and 2, a suction pad comprises a support structure 11 carrying at its lower surface a top portion 12 of the pad and at its upper end a lifting eye 13. Four side portions 14 each have one of their long edges attached to the top of the portion 12 by a rubber hinge member 16 whereby each side portion may be moved from an operative position in which it depends downwardly from the portion 12, to an inoperative position (e.g. as indicated by chain lines 16') in which it extends upwardly from the portion 12.
Each hinge member 16 (FIG. 2) comprises a top strip 17 and a second strip 18 having one of its long edges attached to or integral with the centre line of the strip 17. The strip 17 is clamped to the border region of the upper surface of the portion 12, and to the edge face of the side portion 14, by a rubber cover strip 19 held in place by metal strips 19. The strips 17 and 18 are made of rubber to enable the hinge member to function correctly. At its lower long edge, each strip 18 is secured to a length of woven wire cloth 24 running substantially the whole length of the adjacent side portion 14. The side portions 14 are each formed with a recess 20 which in the operative position of the side portions opens into the space below the top portion 12 of the pad. Each recess 20 is provided with an inlet connection 32 whereby an external vacuum source (not shown) may be connected with the chamber provided by the recess. The wire cloth 24 extends fully across the opening of the recess and carries on its side remote from this opening an apertured plate 34 which provides one of the holding surfaces 3-6 of the pad.
Although four side portions 14 have been shown in FIGS. 1 and 2 (providing two pairs of opposed lifting surfaces 36) it will be appreciated that the invention also extends to the case where only one pair of such surfaces is present or is in its operative condition. The separation of the surfaces of the or each pair of surfaces is of course designed to correspond to the dimensions of the article to be lifted.
In operation of the pad, the side portions 14 are moved into their inoperative positions and the bottom surface of the top portion 12 is lowered onto the top surface of the article to be lifted. The side portions 14 are then pivoted about hinge members 16 into their operative positions (e.g. manually, using handles 38), and the vacuum source is connected with the inlet connections 32 by tubing (not shown). The effect of applying suction to the recesses 20 is to draw the side portions 14 into gripping engagement with the sides of the articles to be lifted, sealing strips 40 at the bottom of portions 14 being effective to provide adequate sealing of the recesses from the surrounding atmosphere. With the pad thus sealed onto the article, the pad can be lifted by its hook 13 and moved with the supported article to some new location. The pad is then lowered, the vacuum source disconnected, the portion 14 moved into their inoperative positions and the pad moved away for further use.
It will be understood that the vertical extent of the lifting surfaces may be sufficient to allow two or more similarly dimensioned articles to be lifted at the same time provided that together these articles present appropriate surfaces with which the lifting surfaces of the pad can co-operate. This property is especially useful when the pad is used in combination with a method of splitting concrete panels as will be hereinafter described in more detail in connection with the embodiment shown in FIG. 3 of the drawings.
The top portion 12 may also present a lifting surface; this allows additional support to be given to the article during lifting besides providing the pad with a convenient resilient surface which lessens the possibility of damage to the upper surfaces of the article (as for example might otherwise occur if the pad was being used to lift uncured concrete panels). This additional lifting surface is provided in much the same way as for the side portions 14, that is to say the top portion 12 provides a body portion formed with a recess 42 (FIG. 2) opening into the space below this portion, and separated from this space by a wire mesh cloth 44 carrying on its lower surface an apertured plate 46. Sealing strips 48 are secured around the edges of the lifting surface thereby provided, and an inlet connection (not shown) allows connection of the recess 42 with an external vacuum source (not shown). In operation this additional lifting surface, if present, will normally be used in combination with other lifting surfaces presented by the side portions of the pad.
portions 102 are in addition provided with sealing pads '104 at their lower ends, that is to say removed from the lower surface of the top portion 100. Tubing 106 is provided at the top of the pad for connection with an external vacuum source (not shown), the lower end of the tubing communicating via channels 108 with a vacuum chamber bounded in part by the inner surfaces of the top portion 100 and side portions 102 and with a sub-chamber 109 bounded in part by the lower surface of the top portion 100 and by sealing pads 110 located at the periphery of this lower surface adjacent to the roots of the side portions 102. The remaining boundaries of the chamber and sub-chamber above referred to, are provided, in operation, by external surfaces of the article(s) 111 to be lifted. Conduit means (not shown) connect the space between the pads 104 and 110 with the tubing 106.
As will be seen from FIG. 3, the sealing pad 104 for the side portions is carried on an inwardly projecting flange 112 so as to present a vertical lifting surface 114 to the article to be lifted.
The operation of the above embodiment is analogous to that already described with reference to the embodiment of FIGS. 1 and 2, the lifting surfaces presented by the side portions being used in place of the lifting surfaces 36 of the first described embodiment, and the sub-chamber 109 bounded by lifting pads 110 being used (if desired) in place of the additional lifting surface presented by the top portion 12 of the first described embodiment. The subchamber will be used, for example, when articles of low rigidity such as uncured concrete panels are being lifted.
FIG. 3 shows the suction pad of the second embodiment in use with the two halves of a concrete panel split into two using the block splitting method described below.
In this method the concrete mix is poured into the mould around resilient members which provide the resulting panel 118 with a number of bores 120 passing from end to end of the panel. The panel is then removed from the mould, using the sealing pads 104 and 110, and is stacked in an appropriate place. To split the panel, it is then sufiicient to release the vacuum applied to the space between pads 104 and 110 and to move the suction pad upwards thereby to lift the upper portion of the panel away from its lower portion. The resilient members can then be removed from the concrete and the top portion of the panel replaced on the bottom portion. The suction pad can then be used as illustrated in FIG. 3 to move the two halves of the split panel to some new location.
In a variation of the suction pad shown in FIG. 3, additional (upper) sealing pads are provided on the side portions 102 (above pads 104) and sealing pads 110 are omitted. An appropriate valve arrangement allows either the space between pads 110 and the additional pads or just the space above the additional pads to be brought into operation as desired.
In a further variation, the sealing pads 110 are omitted and the lower surface of the top portion 100 is provided with a perforated plate and wire mesh in the same way as is the corersponding lifting surface of the embodiments of FIGS. 1 and 2.
1. A suction pad for lifting an article having a top surface and side surfaces extending downwardly from said top surface, said suction pad comprising:
a top portion to be located over said top surface of said article,
top vacuum holding means substantially confined to said top portion,
side portions adapted to depend downwardly from said top portion,
side vacuum holding means substantially confined to said side portions,
first means to permit connection of said side holding means with a vacuum source,
second means to permit connection of said top holding means with a vacuum source, and
said first and second means being independently operable to permit independent operation of said side and said top holding means.
2. A suction pad as in claim 1 comprising:
a hinged connection between said top portion and said side portions whereby said side portions may be moved relative to the top portion to increase or decrease the separation of the holding means, and
means for moving said side portions relative to said top portion.
3. A suction pad as claimed in claim 1 wherein side portions are provided with recessed parts at their inner surfaces, said holding means comprise apertured plates adapted to cover said recessed parts, and said inlet means comprise duct means opening into said recessed parts.
4. A suction pad as claimed in claim 1 comprising a recessed body portion associated with said top portion and means for applying suction to the recess within said body portion to enable suction to be applied also to the top surface of the article.
5. A suction pad as claimed in claim 4 wherein sealing means are associated with said body portion for engagement with said top surface of said article to be lifted.
References Cited UNITED STATES PATENTS 9/1967 Dean 294-X EVON C. BLUNK, Primary Examiner D. D. WATTS, Assistant Examiner US. Cl. X.R.