Device for transporting hollow bodies

1. A conveyor device ( 10 ) for transporting hollow bodies formed of a thermoplastic material, which comprises:

at least one means ( 16 ) for grasping a hollow body which is to be displaced along a given trajectory, comprising at least one cam follower ( 30 A, 30 B) constructed of an electrically conductive material;

at least one fixed cam ( 32 ) for the control of the means for grasping ( 16 ), arranged longitudinally to at least one section of the trajectory of the means for grasping ( 16 ) and designed to cooperate with the cam follower ( 30 A, 30 B), the cam ( 32 ) being constructed of an electrically conductive material;

a contact layer ( 34 ), which is formed of an electrically insulating material and is interposed between the cam ( 32 ) and the cam follower ( 30 A, 30 B);

wherein the cam follower ( 30 A, 30 B) is connected to a source of a first electrical signal (P 1 ), wherein the cam ( 32 ) is connected to a source of a second electrical signal (P 2 ), and wherein the device ( 10 ) is provided with an element ( 36 ) for the detection of electrical contact between the cam follower ( 30 A, 30 B) and the cam ( 32 ), thereby signaling the deterioration of the layer ( 34 ).

2. The device ( 10 ) as claimed in claim 1 , wherein the source of the first signal (P 1 ) is provided by the ground potential.

3. The device ( 10 ) as claimed in claim 1 , wherein the second electrical signal (P 2 ) for the cam ( 32 ) is a potential which exceeds the potential of the first electrical signal (P 1 ) for the cam follower ( 30 A, 30 B).

4. The conveyor device according to claim 1 ,

wherein the detection element ( 36 ) is formed by an electric dipole which is capable of detecting the flow of an electric current and is interposed in the electric circuit between the source of the second electrical signal (P 2 ) and the fixed cam ( 32 ), whereby electrical contact between the fixed cam ( 32 ) and the cam follower ( 30 A, 30 B) results in the flow of an electric current on the interior of the electric dipole.

5. The device ( 10 ) as claimed in claim 1 , wherein the cam follower ( 30 A, 30 B) and the cam ( 32 ) control opening and closure of the means for grasping.

6. The device ( 10 ) as claimed in claim 1 , wherein the means for grasping ( 16 ) comprise a clamp ( 20 ) which is mounted on the end of an articulated arm ( 18 ), and wherein the cam follower ( 30 A, 30 B) and the cam ( 32 ) control orientation of the arm.

7. A conveyor device ( 10 ) for transporting hollow bodies formed of a thermoplastic material, which comprises:

at least one means ( 16 ) for grasping a hollow body which is to be displaced along a given trajectory, comprising at least one cam follower ( 30 A, 30 B) constructed of an electrically conductive material;

at least one fixed cam ( 32 ) for the control of the means for grasping ( 16 ), arranged longitudinally to at least one section of the trajectory of the means for grasping ( 16 ) and designed to cooperate with the cam follower ( 30 A, 30 B), the cam ( 32 ) being constructed of an electrically conductive material;

a contact layer ( 34 ), which is formed of an electrically insulating material and is interposed between the cam ( 32 ) and the cam follower ( 30 A, 30 B);

wherein the cam follower ( 30 A, 30 B) is connected to a source of a first electrical signal (P 1 ), wherein the cam ( 32 ) is connected to a source of a second electrical signal (P 2 ), and wherein the device ( 10 ) is provided with an element ( 36 ) for the detection of electrical contact between the cam follower ( 30 A, 30 B) and the cam ( 32 ), thereby signaling the deterioration of the layer ( 34 ), and

wherein the cam follower ( 30 A, 30 B) is formed by a roller covered with a rolling tread which forms the insulating material layer ( 34 ).

8. A conveyor device ( 10 ) for transporting hollow bodies formed of a thermoplastic material, the conveyor device comprising:

means ( 16 ) for grasping a hollow body which is to be displaced along a given trajectory, comprising a cam follower ( 30 A, 30 B) constructed of an electrically conductive material;

a fixed cam ( 32 ) for control of the means for grasping ( 16 ), arranged longitudinally to at least one section of the trajectory of the means for grasping ( 16 ) and designed to cooperate with the cam follower ( 30 A, 30 B), the fixed cam ( 32 ) being constructed of an electrically conductive material;

a contact layer ( 34 ) formed of an electrically insulating material and interposed between the fixed cam ( 32 ) and the cam follower ( 30 A, 30 B);

a source of a first electrical signal (P 1 ) connected to the cam follower ( 30 A, 30 B);

a source of a second electrical signal (P 2 ) connected to the fixed cam ( 32 ); and

a detection element ( 36 ) for detecting of electrical contact between the cam follower ( 30 A, 30 B) and the fixed cam ( 32 ), thereby signaling deterioration of the contact layer ( 34 ),

wherein the detection element ( 36 ) is formed by an instrument for measurement of potential difference, one terminal of which is electrically connected to the fixed cam ( 32 ) and another terminal of which is electrically connected to the cam follower ( 30 A, 30 B), whereby a drop in voltage indicates electrical contact between the cam follower ( 30 A, 30 B) and the fixed cam ( 32 ).