Show image from controller in rails

I am displaying an image in view using <%= image_tag(@staff.attachment_url(@staff.image), alt: "No image", width: "100px", height: "100px") %> which is working fine.

Here attachment_url is method for creating dynamic url every time you open the image i.e. staff_profiles/images/b64f8b457dddf968712401bf07a8d08ba7f1ce3a326598ec2144f1c995309e06 and also this image is valid for 30 second only and after 30 second when you refresh or open the same url it will show Access denied.

Everything here is working fine.

Like this image i have other attachments to download/view with download link. when any user open page this attachment_url calls at the time of page load / show method but after 30 seconds this download link expires and when user click on the link it shows Access Denied. I want to call the attachment_url when user click on download link after 1 minute or 5 minutes or 10 minutes of page load.

So I need to open the image or create download link url from controller, Not like mentioned above and also want to use the method given above attachment_url which will help to create url dynamic.

Thanks