Disposable razor suitable for injector blades

Not all razors are meant to become heirlooms. Some are meant simply to be a disposable razor. Or, as Roy E Mullen said it in his 1966 patent application:

There are many occasions when an individual would find the use of a good razor to be a comfort and convenience, under circumstances where the services of a barber are not readily available and where it is either undesirable or uneconomical to purchase an ordinary razor.

From US patent 3,413,720

Visually similar to any other disposable razor, what attracted me to this patent was it’s use of standard injector blades. That, and the multiple drawings on how to insert the blade into the moulded razor. Complete with arrows, and circles, and paragraphs explaining what they are.1

The razor would be – according to the patent – moulded in one piece. The head would have a slot just wide enough for the blade, and with an integral backstop. It would feature an open comb, which would likely be easier to demould than a safety bar. Inserting the blade after the handle was moulded – as opposed to during moulding – would likely make it easier to cast the handle. At the same time, it would also introduce more steps to the manufacture, possible driving prices up.

This is also different than all the other disposable razors I’ve looked at beforethey have all had the blade moulded or otherwise secured in place.

Drawing from US patent 3,413,720 showing a disposable razor set up for injector blades.
Patent drawing from US patent 3,413,720

Inserting the blade

As mentioned, the razor would be moulded without the blade. The blade, as shown in figure 5, is a standard injector blade. This would be slid into the holder, then pushed against the backstop. A dab of glue would hold it in place.

Or, as the patent says in the typical verbose way:

FIG. 7 is a top plan view of the razor head, showing the blade partly inserted in a slot in the head, the direction of movement of the blade for further insertion being indicated by the arrow;
FIG. 8 is a top plan view of the razor head and blade, showing the blade inserted in the slot along its full length, the arrows indicating the locations at which and the directions in which force may be applied to complete seating of the blade in the slot in the razor head;
FIG. 9 is a top plan view of the razor head showing the blade seated in the head, and showing the application of a drop of a liquid bonding material; and
FIG. 10 is a top plan view thereof after hardening of the bonding material.

From US patent 3,413,720

It should, of course, be possible to pry of the glue and replace the blade. That said, the head of this disposable razor is very much not set up to handle the standard injector blade injectors.

Thoughts on the razor

I like this, despite it being a disposable razor. The angle on the head looks good, and it is set up to take a standard blade. This would simplify logistics when it came to production. And since the patent expired in 1985, it is free for anyone who have an injection moulding press standing idle.

A little tinkering with the design should make it easier to get the blade in and out too – for instance the opening in the top could be made wide enough that a small screwdriver could engage the two slots in the blade. A disposable with a replaceable blade would be something novel in today’s market.

The full patent can be found at Google Patents. I also got a page full of old shaving patents and oddities if that is your jam.


  1. Although not on the back of glossy pictures, sadly.

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