GB1583349A

GB1583349A - Pistons

Info

Publication number: GB1583349A
Application number: GB50475/76A
Authority: GB
Original assignee: Hepworth and Grandage Ltd
Current assignee: Federal Mogul Bradford Ltd
Priority date: 1977-11-23
Filing date: 1977-11-23
Publication date: 1981-01-28

Description

(54) CONTINUOUS DRIER FOR LEATHER (71) We, INDUSTRIA TICINESE ESSICCATOI SPECIALI, I.T.E.S., S.p.A., an Italian Company, of Via Marcona, 49 - 20129 Milan, Italy, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- For carrying out the drying of skins and similar materials, it is known that there are in existence in the art various types of driers comprising drilled boards, namely slide-type, rotary and endless belt driers, driers having frames mounted in series and others, in which steps are taken to prevent contraction of the skins during drying.In substantially all these driers, the skins are clasped at their periphery by means of grippers or clamps of various types and all adapted to be manually operated, the said grippers being connected to the board by means of a bottom hook provided on them which is inserted into one of the numerous suitable holes in the subjacent board to keep the skins fixed and stretched during the drying process. In some types of driers, the drilled boards are divided into two or more extensible parts which allow further stretching of the skins after clamping, with a corresponding gain in the area of the skins being treated.

In all these driers, it is necessary to resort to the intervention of operators for performing various operations and especially that of loading the skins (which requires the clamping of the skins themselves and/or the application of the grippers to the drilled boards with tensioning of the skins) and also that of unloading (which requires operations which are the opposite of the previous operations).

It follows that known driers have the disadvantage of a considerable use of manpower and, at the same time, that of discontinuous working due to the need for stops, which are not short, for loading and applying the skins.

In accordance with the present invention there is provided a drier for skins having an enclosed drying zone, an externally accessible loading and unloading zone and an endless conveyor for conveying the skins from the loading and unloading zone through the drying zone and back to the loading and unloading zone wherein the conveyor has the form of a rolling shutter with slats capable of movement towards and away from one another, each slat comprising two elements which are movable longitudinally with respect to one another and which carry respective grippers for grasping the skins, and wherein releasing means are provided upstream of the unloading zone for engagement with the grippers to release their grip on the skins and driving means for the conveyor are provided in the loading and unloading zone and are constructed to move the slats of the conveyor closer together in the said zone.

The positioning of the grippers at the edges of a skin and the closing of the grippers can be effected manually but preferably the drier includes mechanism in the loading and unloading zone for advancing each of the grippers towards the edge of a skin placed on the conveyor, each gripper being slidably mounted on its respective slat element, the advancing mechanism including for each gripper a sensor for detecting the edge of a skin, the sensor being arranged to stop the advance of the gripper and engage the gripper with the skin when the edge of the skin is detected.

In a preferred embodiment of this drier: - the slats of the conveyor belt are fast with the links of two chains of the conveyor belt itself which are passed around toothed or plain wheels, the said links being connected by pins housed in oval slotted holes in the links themselves; - the grippers are mounted on the said elements of the slats, guided slidably in longitudinal slots in these elements and arranged to be pushed from the periphery towards the centre of the conveyor belt, in opposition to the action of a return spring, by L-shaped elements independent of the belt, the lower arm

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

(54) CONTINUOUS DRIER FOR LEATHER (71) We, INDUSTRIA TICINESE ESSICCATOI SPECIALI, I.T.E.S., S.p.A., an Italian Company, of Via Marcona, 49 - 20129 Milan, Italy, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- For carrying out the drying of skins and similar materials, it is known that there are in existence in the art various types of driers comprising drilled boards, namely slide-type, rotary and endless belt driers, driers having frames mounted in series and others, in which steps are taken to prevent contraction of the skins during drying.In substantially all these driers, the skins are clasped at their periphery by means of grippers or clamps of various types and all adapted to be manually operated, the said grippers being connected to the board by means of a bottom hook provided on them which is inserted into one of the numerous suitable holes in the subjacent board to keep the skins fixed and stretched during the drying process. In some types of driers, the drilled boards are divided into two or more extensible parts which allow further stretching of the skins after clamping, with a corresponding gain in the area of the skins being treated.

In all these driers, it is necessary to resort to the intervention of operators for performing various operations and especially that of loading the skins (which requires the clamping of the skins themselves and/or the application of the grippers to the drilled boards with tensioning of the skins) and also that of unloading (which requires operations which are the opposite of the previous operations).

It follows that known driers have the disadvantage of a considerable use of manpower and, at the same time, that of discontinuous working due to the need for stops, which are not short, for loading and applying the skins.

In accordance with the present invention there is provided a drier for skins having an enclosed drying zone, an externally accessible loading and unloading zone and an endless conveyor for conveying the skins from the loading and unloading zone through the drying zone and back to the loading and unloading zone wherein the conveyor has the form of a rolling shutter with slats capable of movement towards and away from one another, each slat comprising two elements which are movable longitudinally with respect to one another and which carry respective grippers for grasping the skins, and wherein releasing means are provided upstream of the unloading zone for engagement with the grippers to release their grip on the skins and driving means for the conveyor are provided in the loading and unloading zone and are constructed to move the slats of the conveyor closer together in the said zone.

The positioning of the grippers at the edges of a skin and the closing of the grippers can be effected manually but preferably the drier includes mechanism in the loading and unloading zone for advancing each of the grippers towards the edge of a skin placed on the conveyor, each gripper being slidably mounted on its respective slat element, the advancing mechanism including for each gripper a sensor for detecting the edge of a skin, the sensor being arranged to stop the advance of the gripper and engage the gripper with the skin when the edge of the skin is detected.

In a preferred embodiment of this drier: - the slats of the conveyor belt are fast with the links of two chains of the conveyor belt itself which are passed around toothed or plain wheels, the said links being connected by pins housed in oval slotted holes in the links themselves; - the grippers are mounted on the said elements of the slats, guided slidably in longitudinal slots in these elements and arranged to be pushed from the periphery towards the centre of the conveyor belt, in opposition to the action of a return spring, by L-shaped elements independent of the belt, the lower arm of which is in the form of a fork with tapered ends bearing a sensor for detecting the presence of the skins;; - the grippers comprise a fixed toothed lower jaw, a movable upper jaw swinging about a fixed pin, a closing spring, and an opening lever system provided with a rounded head for engagement by the releasing means for opening the grippers; and a a disengaging device actuated electrically or by fluid pressure and arranged to disengage a latch which holds the gripper in the open state is associated with the said right-angled guides.

The invention will now be described in greater detail, purely by way of example, with reference to a preferred embodiment thereof illustrated in the accompanying drawings, in which: Figures 1 and 2 are general views, from the side and from above, respectively, of a drier according to the invention; Figures 3, 4 and 5 show one of the grippers of the drier in two side views (closed and open) and from above;while Figure 6 illustrates the control system for positioning a gripper on a slat element; Figure 7 shows in detail the system controlling the automatic opening of the grippers; and Figure 8 illustrates a drive mechanism for drawing the conveyor belt for the skins through the drier and for shifting the slats of the said conveyor close together in the loading and unloading zone of the drier; and Figure 8A illustrates an alternative drive mechanism.

Referring to the drawings, it can be seen at once that the drier comprises a frame 1 (Figures 1 and 2) closed by panels after the fashion of a box, within which moves a conveyor belt assembly 2 of the rolling shutter type comprising lateral chains 3 passing around guide wheels and a plurality of transverse slats 5 bearing grippers 5 for grasping the skins.

As can also be seen clearly in Figures 1 and 2, the drier provides a loading and unloading zone 6, drying zones 7 and 8, and a zone 9 for automatically unlocking the grippers. In the same Figures, the reference 10 indicates a system for carrying the conveyor belt 2 along and also adapted to control the mutual distance between the slats 4 of the belt itself in the loading and unloading zone 6 (which system is illustrated in detail in Figure 8 and may be replaced by the system illustrated, also in detail, in Figure 8A), while the reference 11 relates to a device for automatically unlocking or opening the closed grippers 5.

The slats 4 forming the rolling shutter type conveyor 2 are composed of two C-shaped elements 4' and 4" of pierced metal plate which can be moved longitudinally towards and away from each other in known manner by sliding on guides by way of self-lubircating shoes or sliding blocks. Each slat 4 is connected at its ends to the links of the chains 3, which links are interconnected by cylindrical pins seated in the slotted oval holes of the links themselves, so as to allow limited approaching or spreading movements between link and link and, therefore, between slat and slat of the conveyor belt.

Each of the elements 4' and 4" df the slats 4 comprises a top longitudinal slot 12 in which a gripper 5 is guided and moved by the system illustrated in Figure 6.

As can be seen therein the grippers 5 are controlled by L-shaped elements 13, the horizontal lower arm of which is in the form of a fork adapted to contain the gripper 5 and having tapered ends 13' bearing detectors 14 of any type (electronic, fluid, mechanical). In order to avoid disadvantages and damage which could be caused by the striking of grippers pushed towards the centre of the conveyor against other grippers which are possibly already in position, a sensing system mounted on the two ends of the fork causes the gripper to be automatically returned in such case to the periphery of the conveyor.

The L-shaped elements 13 are located only in correspondence with the loading and unloading zone 6, the number thereof being equal to that of the grippers by which the skins are grasped. The grippers 5 are biassed towards their outermost position with respect to the slats 4 by one or more bottom springs 15. The elements 13, in turn, are controlled to shift towards the centre of the slat and vice verso by a flexible thrust element 16 constituted by a helical spring, the path of which is constrained by a curved sheath 16' and develops outside the chain 3 of the conveyor. Each element 16 operates at its tip and is controlled by a cylinder and piston unit 17; the element acts on the vertical upper arm of the L-shaped element 13.

Fitted to this same arm of the guide is an electromagnet 18 adapted to control a latch 19 by means of its core to produce the release of the gripper 5. A suitably operated fluid-pressure cylinder could be used as an alternative to the magnet 18.

The gripper 5 (see Figures 3 to 6) comprises two jaws, one of which 20 is fixed and has a toothed end and one of which 21 is movable and formed in two articulated parts and pivoted on a pin 22. A lever 25 for actuating the movable jaw 21 is provided with an attachment 26 terminating in a flexible tonque designed to engage a spring 24 which allows the jaw 21 of the gripper to be kept open in opposition to the action of a spring 27 mounted on the pin 22 and tending to hold the gripper in the closed position of Figure 3, with the gripping element 21 thrust against the jaw 20.

Figure 7 shows in detail the automatic opening system for the grippers which is indicated as a whole by the reference 11 in Figure 1.

The system concerned is substantially a roller 28 covered with a first thick layer 28' of