rapidFOX
Sustainability
Company
Get in touch
Holding by shape instead of by force: the gripper reaches under a rim, into a hole or around a contour, so the load cannot fall out even without contact pressure. Positive locking is the safer solution and always preferable where the geometry allows – it does not fail on pressure loss and is independent of surface condition.
In positive locking, two bodies engage so that movement would be possible only if one of them gave way. Force is transmitted perpendicular to the contact face, not along it. A form-fit mount therefore needs no contact force, no energy and no clean surface: a hook in an eye holds oiled just as it does dry.
Its counterpart is the friction grip, in which friction or a holding force carries the load. That depends on a friction coefficient and on a supply – both of which can change.
A fork under a rim holds downwards but not against sliding out sideways. A mandrel in a core carries with a horizontal axis, not with a vertical one. Positive locking is always direction-dependent: every mount blocks certain movements and leaves others free.
The decisive design question is therefore: in which directions do weight and acceleration act in every position of the sequence – including rotating, tilting and joining – and is each of those directions blocked? Whatever remains open is closed by a latch, a lip or a second mount.
Instead of a friction coefficient, the strength of the shape counts: shear in the pin, bending in the hook or fork, contact pressure at the support – and the load capacity of the point on the part where it is gripped. A rim that carries only a seal in service is not automatically designed for the full weight.
Positive locking also needs clearance and lead-in chamfers so that the operator finds the mount without aiming, and a safeguard against unintended opening.
Positive locking presupposes geometry – rim, bore, groove, contour, eye. If it is missing, or changes from variant to variant, only a friction grip or a combination remains. With new parts an early look at the design therefore pays off: a bore or collar provided for handling costs little on the part and saves a great deal on the gripper.
In practice, parts are often picked up by force and secured by shape: the clamping jaw has a lip that reaches under the rim; a catch fork swings in below the vacuum gripper; the expanding mandrel reaches behind the core. The clamp then determines the position of the part, and the positive locking is responsible for it not falling.
What Entracon offers here is on the matching page.
See what we offer| Mount | Blocks | Remains open without a safeguard |
|---|---|---|
| Fork under rim or collar | falling downwards | sliding out forwards |
| Mandrel in core, axis horizontal | falling downwards, tipping | sliding off along the axis |
| Pin in bore | movement across the pin | pulling off along the pin, rotating about it |
| V-shaped cradle | falling and rolling away sideways | lifting out upwards, shifting lengthwise |
| Hook in eye with safety latch | all directions in tension | compressive loading |
In the blocked direction, yes: it holds without energy and regardless of the surface. But it is safe only if every direction of force occurring in the sequence is blocked and the mount is secured against opening.
In positive locking, geometry prevents movement and force acts perpendicular to the contact face. In friction locking, friction or a holding force prevents movement; it must exceed all releasing forces and depends on surface and energy supply.
No. It needs load-bearing geometry that the gripper can reach under or into. Smooth panels, sheets and panes do not have it – they are gripped by force and, where possible, secured by shape.
One short conversation usually settles more than three quotations. Call or write — you will reach an engineer directly.
Start typing – for example “balancer”, “SAP” or “pipe stress”.
Reach Entracon
How can we help?
Thank you.
