What’s Old is New (Again)

Innovation or Novelty in Vise Jaws?

Seldom has the colloquialism, What’s Old is New, Again, been more appropriate than when considering vises and their accessories. Ubiquitous in their application, vises are not only the most versatile Machine Tool Workholding solution but also the most cost effective as they can be used to hold a wide variety of workpieces. They are less effective when needing to hold a variety of old shaped workpieces, workpieces that are round, or any workpiece that does not have two perpendicular surfaces.?New products on the market aim to tackle this challenge; but will the be effective? History will be our guide in this consideration.?

The Classic Solution

Classically, and let’s be honest in Machine Shops everywhere, even today, machinists will use scrap material of nearly any shape to kind to act as a “shim” to support unique workpieces in a vise. If the workpiece is “close enough” to parallel the machinist is likely to deploy their hammer, or a breaker bar, to apply “maximum” force to the vise; often resulting in damage to the workpiece, vise, or Machine Tool. To compensate for this shaky set-up they will typically slow the speeds and feeds of the Machine Tool to reduce the force applied to the workpiece; slowing production.?

Pendulum/Pivoting/Compensating Jaws

These jaws rotate axially around the centerline of the vise supporting polygonal shaped workpieces. They are most practical when workpieces have flat, smooth sides, even though they are not parallel to each other.?By compensating in this way they transfer holding force more efficiently than shims but remain less effective that other options.

Soft Jaws

The ultimate solution for holding unique workpieces in a vise Soft Jaws are designed to be pre-machined to a net shape of the workpiece. This solution is especially well-suited to round or radiused workpieces and provides for optimal holding force transfer. But this solution undermines the value of the vise as a versatile, quick, and low-cost workholding solution as Jaws are usually only used for a single workpiece and they must be designed and pre-machined. This additional cost, time, and effort is typically reserved for production-type quantities or repeating work. With repeating work changing the jaws, manually, can also be time consuming.?

Quick-Change Soft Jaws

Virtually every Vise manufacturer has at least one Quick-Change Jaw solution. Solutions for Soft Jaws have even inspired new manufacturers, like Chick or Jergens-Bock. The challenge with these solutions becomes scalability. Manufacturers, from time-to-time change and evolve their designs, obsoleting prior jaw connection systems. For companies with hundreds of machined jaw sets this can present a significant issue in both cost, to buy a new system and jaws, and time, the necessary machine capacity to machine the jaws.?This issue has driven perennial interest in a “Holy Grail” like solution; the Pin-Type Jaw system.

Pin-Type Jaw Systems

The earliest available Patent data for a Pin-Type system is from 1995. German national Antonius Theiler filed as the inventor of DE19603579A1; Mold Clamping jaws for a Clamping Device.

Mr. Theiler describes the invention thus, “a shaped clamping jaw for a clamping device…a plurality of clamping rams arranged in a parallel transversely to the plane of the frame and movable independently of one another and a clamping mechanism.” The application includes several helpful diagrams.

Since Mr. Theiler’s inventory has enter the public domain, and the Patent no longer applies, several manufactures have begun to market their own items; seemingly inspired by this patent. This image is of a Pin-Type solution from ROMEHELD.

In the ROEMHELD system the pins are spring loaded, allowing the work piece to be gripped by the pins, compensating for any surface that is not flat, and it can be used to support the bottom of the workpiece preventing damage to the vise or eliminating the use of parallels.

Kurt Mfg, the North American market leader in vises, offers a “3-in-1” jaw plate solution that uses pins to support a workpiece but virtually all of their application information is limited to the elimination of parallels.?

This new design, from Norgren Workholding offers the ability to conform to the workpiece in addition to replaceable tips or grippers, the portion of the pin that contacts the workpiece. Unlike spring loaded systems this design is pre-positioned around the workpiece then the pins, are tighten in place. While videos show the pins being tighten in place by hand the Norgren technical specification do require 67.8N-m or 50Ft-Lbs of force which virtually requires a large torque wrench. Tightened to that specification Norgren does claim 26kN, or 6,500lb-f, of clamping force.?This force, while very substantial is less than the clamping force from a conventional vise.

Summary

Each of these solutions has its’ constraints. Additionally, more sophisticated the solution the greater the expense. Why do we not see these solutions, even solutions as simple as pendulum jaws, in more use through-out the marketplace? The time, effort, and acquisition of these solutions is frequently rivaled by the cost of a dedicated fixture. Sure, there are a few companies who have dedicated all of their workholding to Quick-Change Soft Jaw solutions but even those have their limitations; after all the size of the vise dictates the maximum workpiece size – and that size is likely to be much, much smaller than the average machine tool workspace.

While re-inventions of classic ideas are interesting and novel this novelty remains their greatest constraint. It is also the primary reason why, despite the introduction of similar inventions to the market decades ago, they have failed to proliferate.